Olivier Humbrecht

In part one of his presentation on minerality, Oliver Humbrecht said what minerality is not, and explained the need for a soil full of microbial life to bring the mineral fraction into contact with the organic fraction of the soil. Plants need minerals to grow properly.

Will this mineral fraction give a taste to the wine? “I can’t answer that” he said “this is a subject for the next few decades. It’s very hard to say that because your soil has this mineral fraction, its wines will taste more complex.”

However, “finding a wine with a high mineral content is always a sign of a soil that functions properly and a sign the vine is capable to transfer these minerals from the soil.”

Humbrecht explained that the extraction and transfer is done by different microorganisms in the soil. “A vine that has a high mineral extract also has mycorrhizae on the roots functioning perfectly, able to absorb those minerals.

“So minerality in a wine is a sign that the vine is working properly. But it’s a dangerous statement to [suggest] minerality affects the taste of the wine in terms of flavour. We don’t have the research to clarify that.

First steps, he said, are that “you must learn to recognise minerality on the palate. This very small amount of minerals may not smell of something, but they will taste. Very often it’s associated with acids in the wine especially tartaric. And it will modify the structure of wine in terms of acidity, pH, salinity of wine. A wine with a high mineral content, with lots of ashes, will for sure be a wine that makes you salivate.”

Part of this learning is to avoid confusing “true minerality or true salinity with green acidity.  People have to learn how to distinguish. A big mistake is to confuse unripe characters with actual salinity/minerality.”

Root activity is key to understanding minerality, he said. “Everything in non-organic cultivation favours the development of the green parts of the plant [branches, leaves]. It neglects the root activity and flowering process.” So when you increase the vegetative part of the vine by augmenting photosynthesis, you diminish the importance of root activity and dilute minerality.

Checking to see if a vineyard is managed properly can be done by digging a hole and cutting a piece of fine root.  Under the microscope, Humbrecht said “in vineyards with good organic metabolism, you find lots of mycorrhizae, like a veil of white mushroom filaments. These mycorrhizae are in symbiosis with the roots, using vine sap to satisfy their own sugar and carbohydrate needs.  And they help to degrade the soil around the roots, liberating minerals” in this zone.

But when mycorrhizae are not working properly, for example where soil is compacted or where chemicals have been used, he said, fertilisers are needed so vines get the minerals they need.

Whether your mycorrhizae are working properly or not, all soils are not equal in the minerals stakes. “Not every soil has the capacity to produce high quality clay” he said “and therefore have the capacity to fixate minerals in the soil.

“You can measure the mineral capacity fixation ratio.  It depends on the capacity of the mother rock to degrade into particles small enough. Limestone, calcareous [soil], schist, marl, ferruginous clay and basalt are all soils that have this capacity to produce these interesting elements. But some soil types do not have the capacity to produce minerals and these are usually sandy soils, sandy loam, silt, gravelly soils that are not mixed with marl or richer content.”

Grape varieties, too, can influence the sensation of minerality. Humbrecht said “probably there is an inference that varietal aromatics of a wine can hide minerality. I often say that minerals don’t smell. But some aromatics are often associated with a mineral quality. For example iodine is a volatile compound so you can smell iodine.  If I smell iodine it brings a notion, an association, of minerality to my mind.  But you have to teach your brain not to fall into certain traps, the most common one is not to associate reductive character in wine with minerality or unripe character such as high malic content.“

On the question of high alcohol and lots of new oak, Humbrecht said “anything that detracts from the fundamentals of the wine may hide the minerality. New oak, a very aromatic grape variety: for example many people say riesling is more mineral than gewürztraminer but this is because we look at things from the aromatic point of view. Yet once you dissect the taste, not the flavour, on the palate, you understand what makes you salivate. It’s a tasting exercise.”

He reiterated “minerality is not acidity. Acidity is not minerality”. However biodynamic practitioners report a rise in analytical acidity, anything from 0.5g/l to 2g/l, though it’s still not fully understood why this happens. Humbrecht did say “wine is based on tartaric acid, a strong acid, with two acid radicals which each can combine with minerals. [Biodynamic growers] have seen a change from malic-dominated wine to tartaric-dominated wine, and tartaric acidity is capable of fixing more minerals which are in the wine.”

So minerality is by no means a preserve of biodynamic producers, but the inference is that they get more of this elusive palate sensation.

Olivier Humbrecht

In London earlier this month, Olivier Humbrecht, of Alsatian Domaine Zind-Humbrecht, discussed minerality in wine.

His presentation was part of a tasting of biodynamic wines from members of Biodyvin Syndicat International des Vignerons en Culture Biodynamique, the organisation of which Humbrecht is president, though his discussion was not uniquely about minerality in biodynamic wines.

He kicked off by dispelling some commonly held mis-perceptions: “for most people minerality is reductive, or a certain green flavour, it doesn’t taste fruity or floral, and you end up calling the wine ‘mineral’. Minerals don’t smell.  If stones, or water, or salt smell of something, it’s because it’s associated with an organic compound that is volatile.”

The organic compound commonly associated with minerality is sulphur, about which he said “sulphur is a very broad component in nature, it’s found in very many organic molecules. It smells a lot.  At worst, think of wet dog, mercaptan, H2S.

“These sulphur compounds can be linked into more complex molecules, not smelling obviously like sulphur, and these elements might be associated with some kind of minerality. And the most common mistake is to associate reductive character with minerality. [Another mistake] is to associate certain forms of organic acidity with minerality, if the wine is tight, with green acidity.  All these are not minerality.”

Minerals are present in soil, coming from the degradation of rock by erosion, weathering, frost action, as well as the activity of microorganisms, all of which break down larger particles to smaller particles.  When the size of these particles is smaller than two microns, it is called clay.

Humbrecht said “the finer the structure, the more it can trap minerals in the soil. And minerals are necessary to the plant. But will the minerals in the soil give a taste in the wine, that is questionable” though he did say “the mineral fraction in the soil will be represented in the wine as a mineral fraction.” And it is this that is interesting to analyse in a wine.

“Often people analyse minerality of a wine by analysing dry extract, or reduced dry extract” he said. “This consists of evaporating all the liquids, then burning all the organic elements. Or by calculating the reduced dry extract.  It’s good to have a high reduced dry extract as it shows wine is more concentrated.

“But the organic fraction of a wine is expendable, according to physiology of the plant – you can easily have more sugar, more organic acids, as the vine continues to function. [Dry extract] is something the vine is continuously producing, so it can change with time. It can also be altered if you acidify a wine or add sugar to a wine.

“So when we talk about minerality we should talk about the ashes. Take a wine and burn it till you have only dust left. You end up with few milligrams of dust which directly comes from the earth. It’s the only solid fraction in a wine that you can directly link to the earth, everything else comes from photosynthesis – 99.9% of wine is made from heat, air and light.

“The fraction of minerals is a very, very small quantity. Whether the wine is very acid, or high or low alcohol, it doesn’t really change the mineral fraction.”

And, he added “we don’t analyse the mineral fraction in a wine very often because it’s very expensive. But it’s the best way to see if a wine has been produced from a high or low yield.  The reduced dry extract could be the same for a wine made from 25 or 100hl/ha, but the mineral fraction will be divided by 4.”

Digging deeper into the issue to understand the soil, Humbrecht said “a soil should be able to feed a plant without doing anything. For us having a living soil means having a soil that is able to supply all that the plant needs at different moments in the year. And this is something modern agriculture has forgotten.” He spoke of forests that have survived centuries in a sustainable fashion without man’s interference in the form of soil additions, be they fertilisers or chemicals.

But even biodynamic producers add composts to their soils. Humbrecht said “it’s not really to bring fertilisers to the soil, but to bring something alive, microorganisms, and the elements of humus to stabilise the mineral fraction in the soil and bring energies to bring back harmony into our wines.

“We want our soil to be alive, with worms, fungus, micro-organisms, everything it takes to allow the mineral fraction to combine with organic fraction in the soil. If you don’t have this link the soil will fall apart” for example being eroded after rain, or compacted from repeated machinery passes.

This is so important, he said “because the very small mineral fraction is absolutely necessary for the vines to grow properly.”

Will this mineral fraction give a taste to the wine? Find out what Humbrecht said in part two.

Quinta do Vale Meão, Douro Superior

The Douro is one of the oldest vineyards in the world, and it also ranks amongst the hottest, making it a challenging viticultural landscape.  Yet the region makes some of the finest still and fortified wines known to man.  When all the buzz is about cool climate, why is it cool to be hot in the Douro?

Heat stress is very real in a region where daytime temperatures can reach 40 to 50°C. Additionally, Paul Symington, the managing director of port producers Symington Family Estates highlighted a 1.2°C rise in the average temperature over the past 35 years was plenty to contend with. But, he added “there is no clear pattern of rainfall changing, as there is with temperature. You can say it’s getting hotter, [but] you can’t say it’s getting drier.”

But “there’s always been heat in the Douro” said Pedro Barbosa, the viticulturalist at Quinta do Vale Meão in the Douro Superior “and there were no problems like there are today. In the past, people used mixed grape varieties, so problems were not so exposed.” Single block plantings highlight issues, as do the use of planting particular clones.

In a scientifically modulated reversion to older practices, Antonio Magalhães, viticulturist at the Fladgate Partnership, which makes only port wine, said they “plant in micro-blocks, with the aim to look after the grapes separately during the year, and to ripe them at the same time. We then pick just-ripe, and ripe, and some overripe” to make the port blend. Such micro-planning melds with the multiplicity of aspect, for example, taking advantage of the heat-loving tinta cao on south-facing plots, and planting wind-affiliated tinta roriz on spurs of land, sometimes just a dozen vines in two rows on a tiny plot of particular aspect.

It is aspect that Magalhães argues is the most important consideration in an extreme mountainous environment, and it is a factor that cannot be controlled – orography has created 360° aspects. He said “in the middle of the afternoon, at the same altitude, the difference between north and south is 2°C.” So in a hot climate, Magalhães prefers an east-west orientation where the sun is over the canopy at the hottest time, but he rarely gets this; because of the mountains “we cannot choose the row orientation.”

The evolution of grape varieties is another of the great adaptations, along with the fact that blending different vineyards, different grape varieties, and in the case of Port wine, different years, allows unevenness to be ironed out. But Douro wine requires different fruit parameters, so, said Rui Cunha of Secret Spot wines, “we don’t want to produce over-matured red wines. We’re looking up, 400, 500m to produce elegant wines.” Indeed above around 500m production is virtually all Douro wine – lower altitudes get more points in the port classification system.

Even with the choice of grape varieties, heat stress is considered the most important factor. Winemaker Charles Symington said it’s about “varieties with the best resistance to heat. It’s more about heat than rainfall.

Dry Douro vineyards

“Touriga franca survives best; it’s late ripening, resistant to heat and low rainfall.  We tend to plant it at lower altitudes close to the river, and west facing, which is often the hottest of the four alternatives. It’s difficult to have high Baumés, so it’s ideal for hotter locations. On the other hand, Touriga nacional is earlier ripening, getting higher sugars earlier on. This is interesting if it’s east facing and higher.”

Tinto cão is more recently interesting.  Barbosa said “cão is well adapted but the tannins are rough for still wines” whereas Magalhaes, making only port, would plant cao “for climate change. Viticulturally it is a wonderful grape. In a hot climate it is the best, it has high tolerance to drought and sunburn; it’s late ripening with a high acid content.  But in vinification it is usually less than 5% – it’s not high in colour, it’s not a strong wine.”

Water stress is a variable issue west to east, but winter cover crops have become an important anti-erosion tactic, with a moisture benefit too. Charles Symington said “we thought the cover crop would compete with the vine for humidity, but in summer it dies down. [Then] the dry stubble breaks up the wind and doesn’t let wind erode so much.” But, added Cunha “our experience of planting grasses to fight erosion [has shown it also] makes the soil healthier, and helps fight heat. Making mulch creates shade and reduces soil evaporation, as well as reducing erosion.”

The impetus of dealing with water stress is towards finding ways of working without additional water.  Bringing irrigation water into the vineyards for example by pumping up from the river would be prohibitively expensive, and irrigating vines discourages them from sending roots deep into the schist to look for water reserves.

The lessons are already there, said Luis Seabra, winemaker at Niepoort’s Quinta de Nápoles “mechanisation changed the viticulture of southern Europe a lot. People are making vineyards to be more efficient, to produce more quickly with higher alcohol. So you have higher canopies which suffer more water stress, with roots that are less deep so suffer more in summer. We need to lower the canopy.”

Modern viticulture uses cordon training, so there is a lot of permanent wood. Barbosa said such-trained “20-30 year old vines are dying before the ancient ones”. The traditional guyot training he said “is adapted to Douro.  The trunk height is 25 to 30cm. But with cordon it’s 50cm high then 1m long. So there is 1.5m of old wood with cordon and just 30cm of old wood with guyot.  With a small amount of water, it’s more efficient in guyot.” At Vale Meão all new plantings since 2006 have reverted to the traditional guyot training, which said Barbosa “will still be here when I am not.”

This and other lessons from the past are being re-learnt for the Douro’s extreme climate, and could provide important new lessons for other hot climate zones.

The Douro’s climate data compared to other wine regions

NB: different sources make direct comparisons impossible.
Sources:
The Fladgate Partnership
Viticulture and Environment, John Gladstones
The World Atlas of Wine, sixth edition. Eds Hugh Johnson, Jancis Robinson

These data ensconce the Douro firmly into Winkler and Amerine’s Region IV, which previous work by Dr. Andrew Pirie, has also lined up with, for example, McLaren Vale, the Upper Hunter, Swan Valley and Montpellier in France.

My research visit to the Douro in April 2011 was sponsored by the ‘Discover the Origin’ campaign.

New eggs at Castagna

The first egg vat was commissioned in 2001 by Michel Chapoutier, following discussions and design between Chapoutier and French vat manufacturer Marc Nomblot, whose company has been making concrete wine vats since 1922.  The shapely historic connection to Roman amphorae was not coincidental in the design.

They are made without using chemical additives, according to Nomblot “from washed Loire sand, gravel, non-chlorinated spring water”, and cement.  There is no iron added during manufacture of the eggs. Because the concrete is unlined it must be treated with tartaric acid solutions before use, and tested with a further solution to ensure there is no reaction.

Since 2001, Nomblot has sold some 800 of the vats, which are usually 6hl or 16hl in size.

Concrete arguments in their favour?

Concrete has been used successfully since the 19^th century for winemaking, but the egg shape is new.  Regardless of shape, evaporation loss is quite small, as is temperature fluctuation, though the concrete is liable to crack if temperatures get too high.

A critical thing is a continuous flow of liquid in the egg vat.  Gilles Lapaulus of Sutton Grange Winery, who was the first to import egg vats into Australia, in 2005, said “with this sort of shape there are no dead corners, so there is a better uniformity of the composition of the liquid, in terms of temperature, especially.” And he added “the fermentation kinetics seem more regular, without peaks or slowing down, and it’s less reductive than stainless steel.” Though he was quick to say he’s done no strict comparisons.

Biodynamic farmer Werner Michlits, at Meinklang in Austria has observed a temperature difference of around 1°C between the top and bottom of their eggs, which Michlits said enhances the slow, continuous flow of the liquid. And Lapalus added “the thickness of the wall is important in temperature variation, the shape allows a more homogenous liquid through the circulation inside.”

Eben Sadie in South Africa was an early adopter.  He’s been using them, on his whites, for eight years, and he was so happy he now has half a dozen. He uses the 6hl size, in which he said the fermentation temperature is stable, without artificial refrigeration.  He said, in his ambient cellar temperature of 16°C, “my white fermentations are about 20°C without any cooling. I don’t inoculate and natural ferments are cooler than yeast additions” explaining the effect of the circulation “adds more depth and structure to the wine, but doesn’t let wines go flabby; they stay linear, dense and tight. It’s finer stitching.“

Lapalus agreed, saying “in my experience with viognier, we can have long time on lees with a good control on reductive character, giving a lot of texture to the wine. I don’t see any effect on the acid profile.

Le Clos Rivieral, Languedoc

A similar result has been seen at California’s Spottswoode, who’ve been using egg vats since 2006, as a blending component in their sauvignon blanc. Winemaker Jennifer Williams said “We were experimenting with ways to increase minerality and weight in our white wines at the same time. We like that the concrete preserves the natural character of the sauvignon while also adding richness and body.  The [eggs] act very much like oak barrels in creating texture [but] without imparting vanillan, spice, etc.  They preserve fruit flavours and aromas like stainless does.”

Another oft-cited benefit is a small micro-oxygenation akin to that seen with oak, without imparting oak flavour, and avoiding the reductive conditions of stainless steel.  Sadie said “I tried to find an alternative vessel to wood that could breathe, but that doesn’t give a taste of wood, which is not part of terroir. Concrete allows a higher level of purity, site and place. “

Back in Australia, Julian Castagna recently started maturing his viognier in eggs, which is used in his flagship Genesis syrah.  He said his researches showed him “concrete had a freshness that surprised me and I thought was really interesting.”  And for him this was enough to do his own experiments – “At the level of wine we make, to try and increase quality by even 1% is worthwhile. My gut tells me it will add another level of complexity.“

For reds, maturation is so far the main use.  Almost inevitably Alvaro Espinoza was the first in South America to buy egg vats, in 2009. He has two 6hl vats, saying he was experimenting with the smallest ones because it is very expensive to move them from France.  He is working with carmenere, saying “I wanted to age the wine on its lees after malo. The lees are always in movement, like a continuous battonage, because of the shape of the egg.” Though, he added, it’s difficult to clarify the wines, so afterwards, he puts the wine in tank for 3-4 weeks, then racks.

He said “we did a tasting a few weeks ago.  An egg tank can age better than a barrel. It shows very nicely with a lot of fruit flavours, without oak. But we also get a very good mouth development, round and soft.”  Compared with stainless steel he said “the wine is evolved in terms of tannin structure. The wine increases in volume, mouthfeel and softness, and I prefer the sweetness of the wine.”  Adding “you don’t have reduction in concrete, I haven’t racked all year.”

Espinoza is releasing a single vineyard carmenere from his biodynamically grown grapes at Antiyal under the El Escorial vineyard label. He thinks about 90% of the wine will be using egg vat fruit, with maybe a bit of cabernet sauvignon, but it’s not due to be released for 18 months, so it is still evolving.

Michlits has also found there is “nearly no evaporation of wine” in egg vats.  He’s working with Sankt Laurent, which he presses off to do the malo in the egg vat. Comparing the same wine in stainless steel, oak and concrete, he said “that concrete had the best texture and mouth feeling; it was fuller, rounder, and with more complex darker fruit on the Sankt Laurent. Wood gave more tannin structure; stainless steel was the lightest.”

The downside

What these egg vats are not is cheap, especially if they are being transported half way around the world, which is what seems to be happening. The cost from Nomblot in France is between €3,000 for the 6hl size and €6,000 for the 16hl vat. The small one weighs 1.2 tonnes; the 16hl weighs 2.6 tonnes, so transport costs are substantial. Producers are not experimenting on a whim.  But they last a lot longer than barrels, so cost per use may eventually be economical.

The other main drawbacks include the need to protect against acid corrosion. Castagna said “concrete is more work, but if you prepare it correctly it forms a skin. I can see that in our eggs already – a layer of tartaric acid which is forming on inside of concrete.  Within 2 to 3 seasons, the wine won’t be in contact with concrete it’ll be in contact with tartaric acid.  The shape will be the most important element of it.“

Science beginning to analyse

As to the science, Geisenheim Research Centre has been leading the field with so far one experiment, which Dr. Maximilian Freund calls neither representative, nor science, comparing Rheingau riesling in a 900-litre concrete egg (made by Michlits) and 900-litre stainless steel tank. They concluded Rheingau riesling in 2008 is not particularly well suited to concrete, as its pH is too low for unlined concrete, meaning the wine acids corroded the concrete. Although the concrete did not affect the sensory properties of the riesling.

Freund explained there are two considerations with egg vats, namely the material concrete, and the egg shape.

Of the material he said in regions with a higher pH and lower acidity, such as the southern part of Europe where mostly red wines are made, the wine is not so corrosive.

In terms of the egg shape, Freund said their single experiment didn’t “see any difference in fermentation” between stainless steel and the egg vat. He also found no difference in yeast cell numbers and biomass between stainless steel and egg vat, but they did find the length of fermentation in egg vat was longer, with a little higher residual sugar.

While eggs may be uber-trendy and fun to look at, they are not the new wonder-drug of wine. Lapalus draws us back to reality “I don’t want to create an ‘egg’ wine, it’s too much of a fashion. It’s just a tool not a magic trick. The important work is in the vineyard, then not to miss or destroy the potential in wine making. The whole process is important not only one element.”

“Scientists will tell you this is all rubbish, it has not been proved, but when you reach the level of taste, of smell, something which is not tangible, proof has no real meaning.

“Why does biodynamics play its part in the quality of wine? I start with taking an example: if you were in the vineyard in February, or the beginning of March, in the northern hemisphere, you will see nothing – pruned vines, small sticks with tiny buds. If you return to the same spot six months later, you have branches, leaves, flowers, grapes.

“In six months several tonnes of matter per hectare have appeared. If you take away water from that matter – to get dry matter – 94% of that dry matter comes from photosynthesis. This is a very important key to understand biodynamics. Photosynthesis converts the sun’s forces into matter. 94% of dry matter every year comes from photosynthesis.

“From spring to [autumn] a vine, a plant, is incarnating forces of something intangible, call it wavelengths or frequencies, into matter.  Non-matter becomes matter. This is the key to biodynamics.

“When you say to people we use 10g, at most 100g, per hectare of biodynamic preparations, scientists say this rubbish. They say it cannot work, because this person has been trained in the physical way.

“The main part of a plant is to take something intangible and to contract it into something tangible. The biodynamic preparations have to be viewed as catalysts.

“I describe biodynamics as being a better acoustic. [Imagine] a man with a splendid voice singing in subway [versus] singing in beautiful old church.

“So we help vines to catch a little deeper these forces which will become, in the end, taste and smell, structure and complexity in your glass.  All this is intangible work, in the same way that if you see a beautiful painting, would you give it a score [out of twenty]? You cannot come up with measure for something that belongs to a non-physical world.

“So, with biodynamics, we try to help the soil to feed the root, and to help light and heat to feed the leaves. To help photosynthesis and help the work of the roots.

“You need to understand the forces to understand biodynamics.  Gravity, which means contraction, are the forces that go to the centre of the earth. The opposite forces – sun attraction – are the ‘levitation forces’.  Some biodynamic preparations work up, others work downward, some are in the middle.

“You want an understanding of your place and an understanding of how you can balance these forces in the place where you live. And appellation contrôlée is a specificity of taste from the earth, and a specificity of taste from the climate, so we want to help the leaves catch the microclimate, and help the roots catch the micro-geology. And you want the vine to be as capable as possible to do this process (up and down).

“A side effect of what I’m telling you here is that a clone is a nonsense. Clones have been invading the vine for 30 years and more. A clone takes one vine and makes lots of copies. It is absurd quality-wise. How do you create complexity? But clones are easy to manage because they all flower at same time, and are harvested at the same time. But they are missing the complexity that each vine wants to express.

“Once you understand that you want photosynthesis to be as good as possible, and the work of the root to catch the soil as well as possible, you want the vine to be as lively and as sensitive as possible.

“What has modern farming done to appellation contrôlée?  First, weed killers, which destroy the life of the soil. Then the root cannot feed itself. Roots need the assistance of lot of microorganisms. Weed killers were presented to farmers in the late 50s, 60s. But after six or seven years the roots are starving so they grow back to the surface of the soil. Already the originality of the soil is destroyed.

“Then you need to bring food, so chemical fertilisers came. They are like salt; chemical fertilisers force water into a plant. This is not growth. If you stopped chemical fertilisers, the world would starve because the soil is destroyed – chemical fertilisers have been replacing the soil.  Vines are forced to grow because of the salty solution; it is forced to take up water.  

“Before weed killers and chemical fertilisers, the pressure of disease was lower, and we could solve diseases with simple products, such as copper and sulphur.  If these are used in small quantities, these are not poisons.

“Then came systemics, where molecules go in the sap, so you are sure not to have diseases. But the side effect is it poisons the sap. So on one side the downward process of the root is killed by weed killer, and [on the other] the originality of climate is weakened by systemics. The result is a crop which is not marked by the originality of the place where the vine is growing.  

“Once you understand this, you understand why organic wines are coming back, why biodynamic wines are spreading all over the world. A deeper understanding of nature, respecting nature allows good taste to be achieved. All biodynamics is, is stimulating forces which are specific to the place of the vineyard, which increase the originality of taste.   

“In biodynamics what you have in front of you, the vine, is the incarnation, through photosynthesis, of forces transformed into matter between spring and [autumn].

“With biodynamic preparations in tiny quantities, we are improving specific processes. For example if you put black plastic around the earth, some sort of death will come. So we know life on earth depends on being a member of the solar system.  What forces keep together the solar system? We don’t work at the physical level, we work with the forces that end up at the physical level.  

“With pollution, only the physical pollution of the atmosphere is covered, not the energy pollution of the atmosphere.  But if you fill the atmosphere with billions of frequencies and wavelengths, for example with satellites, antennae, you are weakening the forces that bring life to earth.

“Biodynamic preparations – we can call them Mr. potassium, Mr. calcium, Mr. phosphorus, Mr. iron – help to recreate a system of communication for the plant to receive the forces it needs to help it express itself [that help photosynthesis etc].

“You need to understand the light, heat and earth forces. Heat goes up – it destroys the earthly process [into gas]. Light goes with air. Water is the liquid state. No life on earth [exists] without going through the liquid state. Then there is the earthly level.

“Understanding polarities is what biodynamics is about. If you have a place where the earth is too strong, you can calm down the forces. And you can increase reception for other forces.  If you have too much downward force – wine has no taste. Too much cosmic force – the vine will die. So need to balance it.

“Then you need to understand with these four levels of matter [heat, light, water, earth] what is each animal. Pig manure is linked to earth, so if you are in rocky place with shallow soil, with not enough earth forces, then bring pig manure. Horses are linked to heat. In a place like Champagne, which lacks heat, bring horse manure.    

“By having a deeper understanding of nature, of the forces in each type of plant and animal, of the place where you are, the bottom or top of a valley; which aspect, once you know this, you will know how to use biodynamic preparations. … to allow the plant to express itself. Or to find for the singer the place with the best acoustic to express his voice.

“Then we reach the cellar. When we have 12 hours of day and night we have a balance of the down [gravitation] (autumn) and the up [sun attraction] spring [forces]. The day after spring, you have 1 minute more of day than night – the scale of balance has changed. All the forces are going outward. Then you have the flowering, the reception process. After summer, days are getting shorter, then the movement is a slow contraction into seed. If things are balanced, you have within the grape at the time of harvest everything in the grape that you need, to do nothing in the cellar. The opposite of what is taught in universities.

“So biodynamics is rediscovering the forces that are behind life. The behaviour and understanding of place through biodynamics allows vines to come up with more complex taste.”

Forget closure OTR (oxygen transmission rate) for the moment. In closing up a wine bottle, TPO (total package oxygen) is where the TLAs (three letter acronyms) are at, and the bottling operation is the bigger oxygen issue by far.

TPO is the sum of dissolved oxygen (DO) in the wine plus oxygen in the air of the headspace (HO), and whilst many folk have got their heads around DO, the idea of TPO is still relatively new.

Warren Roget, technical manger at the AWRI (Australian Wine Research Institute) said “normal bottling processes entrain oxygen in the bottle. There is oxygen dissolved in the wine, and there is oxygen in the headspace. Our work shows that 60 to 70% of the total package oxygen is typically contained in the headspace.”  What is concerning, added Roget, is that “it’s typical industry practice to measure DO in wine, meaning the majority of the oxygen in the bottle is not being measured.”  In practice he added, this means QA specifications may state permissible DO levels at less than 1mg/l, but when “you look at TPO, they may be closer to 3mg /l because they’re not measuring oxygen in the headspace.”  Wine specifications should be moving to detail TPO instead of the less relevant DO.

Measuring TPO has only been possible for a few years with the development of non-destructive (i.e. not needing to open the bottle of wine) measurement kits, such as PreSens, OxySense and NomaSense. Standard laboratory equipment only measures DO.

Importantly, TPO is a snapshot measure immediately after the bottle has been packed. “Three months after bottling” said Roget “the TPO will virtually all be consumed by the wine. It is from this point forward that closure OTR becomes the important factor in regulating oxygen intake into the wine. However significant quality and shelf life impacts may already have been incurred.”

Management of headspace is therefore one of the most critical areas for control of oxygen ingress at bottling.  Sometimes remedies are simple, though incur costs: using inert gases, for example nitrogen, or carbon dioxide, to flush out oxygen in the filling tanks, in pipework, the empty bottle, the headspace, prior to the wine being transferred.

According to closure trials done on riesling at Geisenheim Research Centre, Professor Dr. Rainer Jung found that after nearly a year, cumulative OTR varied significantly across screwcap and synthetic, from “0.5 to 2.5 mg/l in total, which is not very much.  It is not enough to oxidise the wine.”

But a different picture emerged with headspace trials. Jung said “we measured 6mg/l oxygen in the headspace. It takes about 4mg/l SO2 to reduce 1mg/l oxygen, so if you have 6mg/l of oxygen, you need 24mg/l SO2.” The first AWRI closure trial identified oxidative characters developing in white wine at about 10mg/l free SO2, and whites are commonly bottled with 30 to 40mg/l free SO2, so, said Jung “if you don’t want to lose of 24 mg/l SO2, flush the headspace [with inert gas].”

Jung highlighted the snapshot significance of DO and TPO, saying wine can arrive at the bottling line with 1-2mg/l DO already in the wine, though this completely depends on what has happened to the wine before, and its style. For example a micro-oxygenised red versus a reductively made sauvignon blanc. And he said, of a reductively made wine, where oxygen has always been kept away “in the last step, you pump into the bottling tank, and get the same amount of oxygen uptake. This will directly react with wine components, so no DO is measured, but the aromatics and phenols can be oxidised.” So the wine is in specification, but its defining characters have been lost.

Even some reds won’t benefit from oxygen at bottling. Stéphane Vidal, global oenology director at Nomacorc, said “syrah is quite reductive. If you add oxygen at bottling, you are simply wasting sulphur dioxide” and shelf life. He added that improving bottling TPO by 2mg/l “could save one year of shelf life of the wine”, if the bottle is closed with their Nomacorc Classic+, for example, which has a 2mg/l OTR over the course of a year.

Headspace management is also a critical control point for traditional method sparkling wine. Michel Valade, responsible for viniculture at the CIVC in Champagne said “the quantity of oxygen that might enter the bottle at moment of disgorgement varies according to conditions of disgorgement.” CIVC studies showed that the amount of oxygen introduced at disgorgement varies from 1 to 10 mg/l, and averaging 2 to 4mg/l.  Valade said that during ageing [sur lattes] “only 1 mg/l per year of oxygen enters the wine, and is consumed by the wine, so 2 to 4mg/l is the equivalent of 2 to 4 years of oxygen transmission through the closure.”

Valade explained “at the moment of disgorgement some bottles let some mousse escape, in which case there will be no oxygen entering the bottle [as the effervescence expels headspace oxygen]. But if bottle is very quiet, or stays a bit longer on the line, up to 6 mg/l may enter the bottle.” This clearly creates big bottle variation which will directly affect the flavour profile. 

The ideal is to have zero oxygen entering all bottles at disgorgement.  And to this end, the CIVC are developing a technique already used by the brewing industry, and, according to Valade, by some of the big Champagne houses, though the CIVC are still completing trials. A tiny amount (20 μL, or 0.02 mL) of wine is injected into the bottle under pressure, after dosage, immediately before the bottle is closed. This provokes the wine to effervesce, which expels the headspace oxygen. 

“Very soon” Valade said “this technique will be widespread in Champagne.” It “is not very expensive, and can easily be installed on the disgorgement line.“ Added to which, he said, achieving a close to zero ingress of oxygen at bottling means producers can use less sulphur dioxide, to achieve a lower final sulphur dioxide measure.

The level of TPO that industry should be aiming for depends on individual wine style, though “generally the lower the better” said Roget. Vidal said their studies showed “on average, DO is 1-2ppm mg/l. And headspace is 1-4mg/l, giving a TPO of 2 to 6 mg/l.” So, he said “A TPO of 2 mg/l is therefore already a good situation – a bottling line that is working fine.“

For the majority of wine which is drunk within two years of bottling, this is all crucial, as high TPO at bottling quickly erodes shelf life. And for these wines, the wine should be ready for drinking at the point of bottling.  Jung said “During bottling and storage the lowest quantity of oxygen coming into the bottle would be the best way to keep the wine in a ‘ready to drink’ situation.”  Roget added “a high TPO can have a shelf life reduction equivalent to 10 years of oxygen transmission through a Saran-tin screwcap.” He said it’s a “completely different order of magnitude with TPO versus OTR.”

It’s clearly time to focus attention on the moment immediately preceding closure.

CASE STUDY – Reh Kendermann GmbH Weinkellerei

Reh Kendermann (RK) moved from measuring DO to measuring TPO in March 2010, with the purchase of NomaSense equipment.  Their winemaker Phillip Maurer explained that some years ago their contract customers wanted to know about oxygen management, so “we started to measure oxygen input at all the different situations in the cellar – racking, filtration, centrifugation, blending, the whole bottling – tank, filter, filler, bottling line.” 

Measurement, by sampling bulk wine was relatively easy, enabling RK to control the whole process. Flushing pipes, tanks, bottles etc., and blanketing wine with carbon dioxide minimised oxygen uptake. But this only measures DO.

With NomaSense, the TPO is measured and the “main goal is to have a TPO in bottle below 2mg /l.” Maurer added that such a TPO measure is now included as standard in the wine specification for Black Tower and the Kendermanns wines.

There are effectively five different styles of terrace that have evolved over time, with differing issues.

Original stone terrace

Firstly, the original stone terraces, called socalcos, with high walls and a flat vineyard surface. Vines, often just one or two rows on each terrace, are planted along the contour. Arduous to create, and extremely expense to renovate, these remain the best system to minimise erosion in the valley, which is said to be the region’s biggest problem.    

Late 19th century terrace

Secondly, an end of the 19^th century development of the original vertical wall, horizontal planting surface, was the lower wall with sloping vineyard surface. Vines are still planted along the contour.  Rui Cunha, of Secret Spot Wines explained “these are bigger terraces, with a shallow slope and small wall, which allowed more rows of vines. These terraces allowed the first mechanisation – with mules and horses to plough.”  With the higher density, said Tiago Alves de Sousa, of Quinta da Gaivosa “there is more competition for the soil, so vines need deeper roots. And the vines are not so vigorous, so they stay compact, and [therefore] use less water”, which is a seriously precious commodity in the Douro.  Alves de Sousa added “on the other terrace types, you need to be more interventionist to manage the canopy.”  

Two-row patamares

Thirdly, in the 1980s, the two-row patamares was developed.  More economical earth banks were built instead of vertical stone walls.  This allowed the mechanisation of many vineyard operations. Vines are planted along the contour. These are generally regarded as the worst type of system and have not been constructed for around 20 years. The unsupported earth banks are liable to suffer erosion.  Earth patamares also tend to be quite long, so the same grape varieties are planted with different expositions along the length of the patamares, which results in differing ripening times.  With these, said Cunha “the earth slope [created] a higher wall than the original terraces. And the two rows gave irregular maturity. You had the hot sun on the outside row and higher humidity on the inside row.”

One-row patamares

Fourthly, the narrow, single-row patamares is the modern expression of the two-row patamares. With only one row of vines, there is enough room between the vine row, planted along the contour, and the base of the earth bank for small machinery to pass. However the erosion issue is not addressed with this system. Above around a 35% slope, this is the modern model for Douro vineyards. The vines “are planted away from the outer edge to protect from the sun.  But the density is very low” said Cunha.

Vertical planting

Fifthly, the ‘up and down’ or vertical system, is where vines are planted up and down the slope, rather than along the contour.  This system is limited to slopes of less than around 35%. It is more efficient because there are no earth embankments taking up valuable slope surface, so vine density is higher than patamares.  Erosion remains a risk on higher gradients, as does the ability to successfully operate tractors. Alves de Sousa said this system is “better than the terraces with earth banks because you don’t lose so much ground.  There is greater density but some erosion.”

Apart from the erosion issue, which is most successfully dealt with using the original system, vine density and exposition are other issues.  Although, said António Magalhães, viticulturist for the Fladgate Partnership “the question of the system is a question of economics [and slope]. We plant all the systems.”  They need different management strategies to deal with manifold differences in altitude and exposition in a mountain environment, as well as the ripening requirements of different grape varieties. José Manso, the viticulturist for Sogevinus said simply “What I do at the top I don’t do at the bottom. I do on one side, but not the other; I do in one month, but not the next.”

My research visit to the Douro was sponsored by the ‘Discover the Origin’ campaign.

We may live in a water-world with water, water everywhere, but more than 97% of the earth’s water is too salty to be drunk or be used in agriculture and industry. Most of the remaining 3% is deep underground or, even now, frozen in ice. Less than 1% of the world’s total water is usable for domestic use, farming and industry. Of this agriculture uses some 70%.  The availability of even this 0.7% of  water is increasingly unreliable, being intimately linked to climate, and therefore becoming less predictable in the face of more extreme climate events, such as extreme flood events in some countries; long term drought in others.

As it becomes more recognised that water is the new gold, stewardship programmes for water management are being created to develop systems of sustainable river basin management, considering issues such as water risk, availability, quantity, quality, and fair-share usage. 

The South African wine industry has been first out of the blocks in thinking about water from the perspective of water boundaries, i.e. catchment, or watershed, areas, which often bear no relationship to geopolitical or parish boundaries.  This approach is out of necessity, Inge Kotze, BWI co-ordinator for the WWF in South Africa said, “our wine industry is located in one of South Africa’s most water stressed provinces – where demand [for water] is already outstripping supply … wine industry expansion is curtailed largely by water availability or lack thereof.” Su Birch, CEO of WOSA added “the increasing cost of water will help drive home the awareness that we need to do something.”

Kotze pointed out the fast pace of change in environmental standards, saying “three years ago no-one had heard of a carbon calculator.  It is the same journey of learning with water footprints: standards and labelling. We need the wine industry to get on the front foot.”

So whilst the global industry may already be familiar with the concept of waste water management, Birch emphasised, “waste water management is different from reducing water usage.” The treatment and re-use of waste water is already monitored as part of the Integrated Production of Wine (IPW), and she added “WOSA is going to work with BWI over the next 12 months to start promoting water neutrality to all our producers.”

Alien invasion

Clearing alien vegetation at Vergelegen

The industry has already identified alien plant species as one of the single biggest threats to water neutrality in the Cape. They use much more water than native species and burn more regularly and at higher temperatures … and, said Kotze, “planting alien trees that grow the fastest to carbon off-set is a shocking disincentive to addressing real carbon neutrality.”

As an agricultural product the key building blocks for grapes are healthy soils and a sufficient quantity of good-enough quality water.  But in South Africa, said Kotze, “invasive alien species, such as black wattle and pine, are degrading our soil and water catchments, and altering the natural fire regime.”

Infrequent fires are an essential part of the Cape Floral Kingdom in which the Cape winelands nestle. Kotze said “in the Western Cape, fire is our friend when it comes appropriately every eight years or longer.” She said “the 2009 fires burnt for five weeks. At Lourensford, which hadn’t burnt for 12 years, 660 species were discovered soon after, so the seed bank comes back once the alien species are cleared. But over 240 acres burnt in both December 2008 and January 2009” which is too frequent. And the wine industry is also severely affected by these fires.

Not only are alien vegetation fires too frequent, they cause large scale damage to infrastructure and soil, as well as threatening property and lives. Because alien vegetation comprises woody, tall trees, Kotze said, they “result in a very high biomass or fuel load, so fires are very hot and prolonged, whereas most fynbos is just that – fine bush, usually growing to hip level, with far lower fuel load / biomass.” Added to which fynbos burns at low intensity heat in short-lived fires due to the lower biomass.

Alien vegetation fires bake soils, which prevents rain water being absorbed. Run off and rapid erosion result.   

Wetlands

Fires are one thing, but alien vegetation has also been invading the natural wetlands of the Cape. Kotze said “the entire lowlands of the Western Cape – all the flat area in and around Cape Town, up the west coast and along the southern coast were all seasonal wetlands, all underpinned by huge groundwater aquifers in the Table Mountain sandstone.”

In an epoch of climate change wetlands are a frontline defence against moderating extreme climatic events. They act as a buffer between precipitation events and demand for water by capturing water and slowing down run off. They also filter pollutants before allowing a slow replenishing of groundwater aquifers. 

Rivers flow again at Boschendal

The Western Cape wetlands, already threatened by urban development have been eroded by alien vegetation literally sucking the life force out of them. Kotze said alien species are “enormous users of water, eucalypts use up to 300 litres per tree, per day in riparian areas on a hot summer day.”  The worst culprits are blue gums, black and silver wattles. 

The strategy of water catchment stewardship would demand they be replaced with natural fynbos. “When the alien trees are removed, the wetlands reappear” said Birch, and “when the wetlands return, the indigenous flora and fauna around them return.”

Kotze said “these groundwater systems form a critical component of our water provisioning strategies,” adding they “will be developing a freshwater stewardship component to the BWI, whereby producers can choose to participate in either the conservation of critically endangered veld types (as they are currently doing) and/ or freshwater habitats (rivers, tributaries or wetlands and estuaries).”  In Elim, Dirk Human of Black Oystercatcher Wines said the hippo is “the latest addition to our wetlands, the first time in 120 years that they’ve been back.” This initiative is part of the Nuwejaars Wetlands area where private land from 25 land owners has been committed to conservation and more sustainable farming.

Elsewhere in the world

South Africa may be the only wine producing country currently looking at an industry-wide initiative, but producers in other water-stressed countries are also taking a leading position.   

New Chilean vineyards

Chile’s largest producer, Viña Concha y Toro, having already measured their carbon footprint for the past three years, is the first winery to be measuring its water footprint.  Laura Noguer, their sustainable development manager said “this is an additional step in our sustainable development strategy and an important sign of our commitment to preserving the environment and its resources.”

In January 2010 Concha y Toro linked up with Fundación Chile and the Water Footprint Network (WFN), an international organisation aimed at promoting a move to sustainable and equitable fresh water use.

Noguer explained “The water footprint of a company measures directly and indirectly used water and it is a multidimensional [measurement] of ‘where’, ‘when’ and ‘how much’ water is consumed, and polluted, considering the whole product supply chain.

“It also explains the type of water that is being used, for example, rainwater (green water), surface and groundwater (blue water), or polluted water (grey water).  The water footprint aims to determine all water consumption at all links in the chain, which are not available for the downstream water system: water that is evaporated (crop evapo-transpiration), withheld (dams) or is otherwise removed from the system (civil works to move water over long distances). Under this logic, contaminated water is water which is not available for later use, and therefore also computed. This methodology, which measures only the outputs of the system, has the advantage that does not allow double counting of water.”

While Concha y Toro wait for the results, potential actions are being discussed for water-use reduction, according to what the results reveal.

Errazuriz has followed in the (water) footsteps of Concha y Toro, and is also working on their water footprint in conjunction with WFN. Head winemaker Franciso Baettig said they will “calculate the Errázuriz water footprint during this season (productive year 2010-2011) by process and product.  The idea is to create an index of the water use in the vineyard and in the cellar. The second stage is to use this information in order to diminish the use of water and become more efficient in water use.”   

They are already anticipating changes to both practices and equipment. Baettig said “we are evaluating the replacement of our earth filters with crossflow filters which require less water for cleaning and washing the equipment and don’t generate earth to be disposed of.” And he added they are thinking how they can “recover all the lees from barrels which will diminish the water consumption for cleaning.”

Liquid waste treatment lagoons at Elgo, Strathbogie

Over in Australia, which, until the 2010/2011 season, had mostly been in drought since 2001, there are no industry-wide initiatives akin to the South Africa example. Though Amy Russell, recently the natural resource management coordinator at the Winemakers’ Federation of Australia and now consultant to the industry via Naturalogic, said winemaking water issues now come under the aegis of the broad environment and wine –  EntWine – program.

She highlighted the logic for a co-ordinated watershed-wide strategy, saying that “for example, in 2008/09, South Australian irrigators were only able to access 16% of their allocation because of the lack of rainfall in the Murray-Darling river system from where their irrigation water is drawn.” Already, she added, private “farm dams must be licensed so that the government can ensure that the landholder isn’t storing too much water and reducing availability to other users in the catchment.”

Necessity being the mother of invention, specific water-reduction and conservation measures are already being adopted. Russell said “conversion to drip irrigation is largely complete, with research now turning to sub-surface irrigation as potentially even more efficient. Partial root-zone drying and regulated deficit irrigation are being used with some success. In the winery, water use efficiency practices include rainwater collection from shed roofs, wastewater treatment for re-use, trigger nozzles on hoses, and dry brushing to clean equipment prior to switching on the hose.”

This sort of reduction of water use in the winery is relevant the world over, and in France, Fitou co-operative Mont Tauch is a founding member of the ‘vinegrowers in sustainable development’ movement, a certified system of improving viticultural sustainability. Among the projects that form part of this certification are a limit on water consumption, and managing waste water. They found water to clean equipment is one of the biggest users of this resource, with a machine-harvester being an especially high user, so the co-op has installed a meter to track the total quantities of cleaning water used, and have started using a pressurised water jet to reduce usage.

Research by the French water agency has been monitoring water use in the area for the past ten years, and Mont Tauch has been involved for the last five years.  This has shown that their more sustainable viticulture has “had a positive impact on the quality and protection of water” according to Jerôme Collas, their vineyard manager, adding, “we’ve done fewer treatments, so less weed killer goes into the water”, and at their Montmal estate he added “we measured water usage two years ago.  And then put on restrictions to reduce usage, by using medium pressure rather than high pressure.”

Pushing the boundaries

As biodiversity goes beyond the perimeters of the property, so does water stewardship. It goes beyond the important parameters of reducing water use and treating waste water. With effective and sustainable water stewardship, downstream shouldn’t be the worst place to be.

No-one seriously disputes that Tasmania is properly cool climate, but a slightly more confusing picture is emerging on the mainland.  And with ‘cool climate’ wines being cool, trendy and of different flavour profile than ‘warm climate’, it’s too easy to let the moniker roll off the tongue without paying due regard to proper climatic data.

Canberra District, ACT

HDDs and MJTs still form the backbone of broad analytical data (see chart below), but part of the confusion in the Australian industry about cool climate may partly be due to a fairly long-standing AWBC reference to ‘warm inland’ regions, namely Riverina, Murray-Darling-Swan Hill and the Riverland, accounting for some 50% of total production, and what became known, as a matter of convenience, as ‘cool’ regions, meant to be the ‘non-warm inland’ regions, being the other 50%. 

But this internal industry distinction is not an official definition and has nothing to do with climate data, and more to do with a splitting out of high cost versus low cost.

It has been modified slightly as Peter Bailey, senior analyst at AWBC explained: “We don’t use the term ‘cool’ anymore because of the confusion surrounding temperature but use ‘cool and temperate’ when the sort of high-level industry supply and demand analysis is conducted.”  Given than climatic temperature zones have a scientific basis which affects viticulture and wine style, producers may mistakenly use ‘cool’ as having an official meaning.

Such internal industry nomenclature notwithstanding, there are patterns in cooler climate Australian viticulture via an enmeshed combination of climate, variety and resultant stylistic expression.

The marginality of ripening  

The limit of ripening for grapes is often used as a measure of climate. What’s cool for shiraz is warm for pinot noir. And pinot noir is useful proxy of cool climate because if it’s grown somewhere too warm, it becomes, hot, blowsy, and just another red wine. To have any varietal character the aromatics and delicacy need to be retained.  

On this measure, some of Australia’s most acknowledged pinot noir/cooler climate areas are coastal and maritime: Geelong, Gippsland, Mornington Peninsula, Tasmania.

Diurnals

But this is not the only story.  High diurnal temperature variations, found at higher elevations, are also crucial for retaining aromatics and delicacy. Where this is combined with the 0.6°C reduction in temperature for every 100m increase in altitude, cooler climate styles emerge.

Orange region, New South Wales

At Brangayne, in Orange, owner David Hoskins said “January can go below 10°C at night. An average day time would be 26°C; a hot day here would be 32°C and really hot is 35°C.” The advantage of this, he said is that “the growing season is long, and fruit is on the vine longer, which means post-veraison flavour development is not rushed by heat. And sugar accumulation here is slower” so resulting alcohol is not so high as in warmer areas. 

Added to which said Hoskins, who has vineyards at 870m and 970m, “we notice it’s worth more than 0.6C between our two properties. The lower vineyard is more open, worth at least a degree more [warmth]. On its western slope, buds burst and grapes ripen earlier than the north-east slopes” of the higher vineyard.  Hoskins reckons the lower vineyard gets more warmth from the prevailing westerly weather.

In Canberra District, which varies from 300m to 800m elevation, Richard Parker of Long Rail Gully Wines said “we’re not Tassie cool, but we’re cool. We have a big diurnal, 25°C in the day to 10°C at night. Our peak summer temperature is around 32°C. These really cool nights maintain our acid. The warmer days give us a riper type character, but cooler nights bring us back.”  He added the cool style is lighter in body, with more finesse and restraint of fruit character with more spice [shiraz], and alcohols held around 13.5%. 

Greater natural acidity

For Phil Sexton of Giant Steps/Innocent Bystander in the Yarra Valley, those cold nights are critical to “drive low pH and therefore keep total acidity high.”  As they are for Richard Thomas of Mayfield Vineyard in Orange, whose vineyards reach 870 to 920m. He said “the high diurnal[s] in the growing season maintain a natural acid backbone, which enhances flavour through gradual flavour development.”

The acidity, or acidification, question is an interesting one from a European perspective, where de-acidification is the permitted norm in EU cool climate regions.

Added to which sunshine, and its management in the vineyard, in the southern hemisphere is different to the northern, as Ron Laughton of Jasper Hill, explained, for his Heathcote region “it’s not only about heat, it’s the quality of the sun. Summer here is radiant, without so much heat – we needed a blanket on every night last summer.  Shiraz needs some sun and warmth to ripen. There are some cooler areas within Victoria, where shirazes show more elegance than mine, but also less ripeness.  Here we get ripe flavours and elegance.  The best indicator for me is not extreme sugar ripeness, but full tannic ripeness, full flavour ripeness, and full acidity still.  In 30 years I haven’t adjusted acidity.  That’s the single biggest indicator that this area is great for shiraz.”

Heathcote may indeed be cooler marginal for shiraz. But it is not ‘cool climate’ by the numbers (see chart), and is a modest 200m above sea level. 

Elevation and aspect – high country    

Altitude is needed to get those high diurnals, but as though in recognition that the cool climate moniker is becoming muddied, ‘high country’ is becoming a term of increasingly common parlance. Indeed Orange is the only GI defined by altitude – vineyards falling over 600m.

King Valley, Victoria

One of the recent pioneers to plant in Orange was Philip Shaw, when he was working at Rosemount. He said “I was flying over here when I was looking, for Rosemount, for somewhere to plant pinot noir and chardonnay. I planted my own back in the 1980s,” at 900m. He added “At 600m it was looking something like southern France, Spain and Italy. Higher up it was looking more like Champagne.”

The King Valley also reflects such dramatically changing climate by altitude. Its 150m altitude north end is notably warm at Milawa, while the 800m Whitlands plateau at its southern end, just some 25 km distant, nudges the foothills of the Australian Alps. Brown Brothers long ago saw the potential of this higher altitude, establishing the Whitlands vineyard in 1982 specifically for fruit for sparkling wines, of which there were none in their range at that time.

The significance of altitude was recognised last year by one of Australia’s three ‘cool climate’ wine shows.  The entry requirements for the International Cool Climate wine show in the Mornington Peninsula state “wines must be made from grapes grown either: south of latitude 37.5 degrees south, or north of latitude 37.5 degrees north, or from a property in the southern or northern hemisphere which has an average January/ July (whichever is applicable) temperature below 19° Celsius, as confirmed by the nearest Bureau of Meteorology site, or vineyard site is above 800m in altitude.” 

The 19°C limit is stricter than Winkler Region I, but, said Meg Brodtmann MW, of Southern Cross Wines, who chaired the competition in 2010 said “the altitude was introduced in 2010 as they were missing out on a lot of cool climate wines based solely on latitude and MJT.” She emphasised “newer regions of Australia are cooler once you go up a bit.”

Another benefit is that the growing season is delayed, so that grapes are not ripening at the hottest point. Alan Cooper of Cobaw Ridge, with vineyards up to 635m, in the Macedon Ranges said “shiraz can be around six weeks behind central Heathcote, yet you can drive there in 25 minutes” before explaining “cool climate shiraz is black pepper spicy, savoury, minerally, earthy, graphite. It could be spicy on the nose and peppery on the palate, or the other way round.”

Similar cool climate style comments are replicated in Canberra District, where Brindabella Hills’ Roger Harris said of shiraz, cool climate brings “an attractive perfume of violets, in a style that is not heavy and weighted down with a load of tannin; it’s not relying on weight and power, more seductive. You want to have another glass of it.“

Lower Yarra Valley

And in the Lower (higher altitude) Yarra Valley an extra couple of weeks are required for ripening compared to the valley floor 230 to 250m below.  The advantage, said Mac Forbes of Mac Forbes Wines, of “picking at least 10 days later, is that the cooler sites have a slower ripening, with a greater retention of aromatics”, another one of those experientially defining parameters for cooler climate.  In addition, Forbes gets his chardonnay from southern slopes (facing away from the sun), to “retain freshness and line” he said.

A southerly aspect was an important decision for Savaterre’s Keppell Smith, a specialist in chardonnay and pinot noir, whose chardonnay has been listed in the latest Langton’s. He said his Beechworth “vineyards face south on sloping ground to avoid the frosts, which fall down the slope.” But, he added “the sun’s still strong, so I have at least one layer of leaves.”

Beechworth vineyards stretch from around 400m to 550m. Slopes are important as frost is an issue, and it is the more altitudinally-forgiving chardonnay that has excelled in this region of passion-driven individuals, where Giaconda’s vineyards are at 400 to 420m, on the opposite side of the road to those of Savaterre.

Whether the drive is towards the Antarctic or into the high country, cool and cooler climate results in wines significantly different from Australia’s previous models.  Mayfield’s Thomas sums it up as “cool climate has less density, it has more fruit expression, more elegance and finesse, it’s less overpowering and more complimentary with food.”  Do we begin to arrive at nuance, not a word yet commonly encountered in a Pom’s caricature of Aussies?

Source:  Wine Australia

Fred Pizzini, proprietor of Pizzini Wines, King Valley, Victoria, October 2010
“Flavours of the earth. Acidity steeliness, with maybe some phenolics.”             

Katrina Pizzini, co-proprietor of Pizzini Wines, and runs cooking classes at the cellar door, on minerality in food, October 2010
“kangaroo meat; salt bush lamb. It makes you salivate; metallic, mineral salts without being salty. Moist.”

Keppell Smith, proprietor of Savaterre, Beechworth, Victoria, October 2010
“a tactile sense in your mouth. A clean, slatey, non-cloying sensation, different from straight acid. You get it more in pinot noir than chardonnay. Almost like a bit of bitterness in our wines which gives a savoury character, makes them nice with food.

“Everyone’s jumped on the minerality gravy train.  But you can taste it. It’s definitely not acid, but it’s linked with acid.  It’s something of terroir. It‘s not something you have a choice about it. You can’t make minerality in a wine. It’s slightly metallic.”

Ron Laughton, proprietor of Jasper Hill, Heathcote, Victoria, October 2010  
“Minerality doesn’t mean salt. It’s a descriptor about the earth itself. Emily’s Paddock has a creaminess about it, not minerality.  Minerality is earthiness. Georgia’s Paddock has mineral-ness. Different stones have different flavours, rocks are not totally inert. Maybe I’m swayed by knowing there’s a difference, there’s a major difference in the subsoil. Minerals are expressing themselves in a different way.”

Alan Cooper, proprietor of Cobaw Ridge, Macedon Ranges, Victoria, October 2010
“A lot of minerality is acidity; natural acidity. Sure it’s coming from the soil, it’s the whole combination of terroir.”

Roger Harris, proprietor of Brindabella Hills, Canberra District, New South Wales, October 2010
“Minerality is backbone in riesling; a combination of acidity and phenolic characters in the grape – firmness, tightness.”  

Ken Helm, proprietor, Helm Wines, Canberra District, New South Wales
“Minerality from volcanic ironstone. Minerality is clean, fresh, it exhibits characters of the vineyard.  A ferruginous minerality.  Minerality is a balance, no element stands out.”

Michael Walker, winemaker, Faisan Estate, Orange, New South Wales
“Acidity gives a crushed rock, flinty minerality.”

Plus one contribution from
Louisa Rose, chief winemaker, Yalumba, Barossa Valley, South Australia, November 2010, in London. 
Minerality is “a textural thing, a dryness to the palate. It can look a bit like phenolics. It’s a pebbly, wet stone texture.”  

My research visit to Australia in October 2010 was sponsored by Wine Australia.

There’s excitement in France at the new Vin de France category, in effect from the 2009 vintage, which means wines started coming on the market about six months ago.

South of France vineyards

The new category has been created as a result of massive wine sector reform in the European Union, which is seeing large-scale voluntary uprooting, and the phasing out of subsidy support mechanisms which have contributed to overproduction. 

In France, underneath the Appellation d’Origine Contrôlée wines (which are to become Appellation d’Origine Protégée) and Vin de Pays (which are to become Indication Géographique Protégée) lies basic table wine. Until the 2009 vintage, table wine could give no details of its grape variety composition or its year of harvest, which it has been argued, makes it difficult to create and market strong wine brands effectively. Thanks to the innovative marketing techniques of the new world in the 1980s and 1990s, many of the wine world’s consumers buy their wines by grape variety rather than appellation such as Bordeaux, Burgundy, Côtes du Rhône or Ribera del Duero.  

The new category is a major change at the price-fighting end of French production. Not only can grape varieties and vintage be incorporated as part of the label and brand proposition, but blends can be put together from a mix of French regions (and the same rules apply in other European Union countries).  Chris Skyrme, who represents the organisation promoting the new Vin de France, said producers using “sauvignon blanc have already taken advantage of inter-regional blending” adding the new Vin de France category “has a level of flexibility which  new world countries have had forever, and there is more competitivity, which needs to happen at this quality/price level.” 

He added “the category will help build and promote brands in France.”  If France is to compete against strong new world brands, it certainly needs such extra flexibility and labelling possibility.   

One of those sauvignon blanc producers whose already taken advantage of the inter-regional blending opportunity is Lacheteau in France’s Loire Valley, which produces a wine called Kiwi Cuvée, so named because a New Zealand winemaker put the original blend together from Loire fruit. The brand has been around for about a decade. Tim North, the managing director of the brand’s owner, Les Grands Chais de France, said the new Vin de France category has given them “the ability to produce better blends that are more consistent vintage after vintage. Some years in the Loire it’s a bit lean, we can blend in fruit from Gascony [in south west France] or even from the south in some years, and make better quality.” 

He added “for commercial brands it’s a real opportunity to improve quality and do exactly what Australia has been doing with ‘South East Australia’ for several decades. At the volume branded level it gives us a more level playing field with the likes of Australia.”

Good bacteria exist in wine as well as in probiotic formulations. Their greatest vinous contribution is the malolactic fermentation (MLF or ‘the malo’).  This winemaking tool was pretty much a mystery until the middle of the 20^th century. It was just observed in spring that wines maturing in tank and barrel started bubbling, in tune with the rising of the sap in the vines.  In fact, these various species of lactic acid bacteria only come out to play in warmer rather than cooler weather, and they really get partying over 18°C, so winter in the naturally cool European regions was a hibernation period for them.

MLF lowers acidity, increases microbial stability and changes the flavour profile

Now the science of MLF is understood, it can be controlled. Wine can be inoculated with blends of bacteria to reduce some of the unpredictability of the malo process. Additionally, if the winemaker wants to speed through the MLF straight after the alcoholic fermentation, s/he can manage the temperature to encourage the bugs to do their business. 

At its most basic malic acid (think crisp, crunchy apples) is transformed in softer, rounder lactic acid (think milk), with carbon dioxide as a by-product, which dissipates into the air during wine maturation.  If MLF occurs in bottle, then a spritz will develop, which probably isn’t very tasty in a red wine and it likely to be considered a fault.

The three fundamental effects of MLF are a lowering of acidity; an increase in microbial stability, because the bacteria have done their work, and the addition of alternative flavour compounds such as diacetyl which gives a buttery character.  In concentrations of 1 to 4 mg/l diacetyl can be desirable, over 5mg and it’s a bit like slathering your tongue with the real thing.

On the down side, there can be a loss of fruit and varietal definition due to the breakdown of fruit esters by the bacteria, and if acidity is lowered too much this can encourage the bad boys of bacteria to crash the party which spoils the wine.

South Africa’s Napier Vineyard winemaker Leon Bester said: “To avoid MLF add sulphur and chill to 10°C. If this isn’t enough, the last option is to take the wine off its lees” (the dead yeast cells left after fermentation which provide nutrients for the bacteria). Lees are good for building weight and texture in a wine, so winemakers often want to keep the wine on them for as long as possible.  

Malo goes better with some grape varieties than others. Chardonnay has great affinity with MLF.  But malo is not always a good idea for varieties such as riesling and sauvignon blanc. Whilst they do both have high natural acidity, the focus of flavour for the vast majority of wines made from these grapes is their primary fruit characters uninfluenced by techniques that might detract from this pristine expression, such as oak, or indeed, MLF.

Most reds undergo MLF. With their lower acidity, and lower sulphur regime it is more challenging to prevent it. And anyway, the extra degree of smoothness and suppleness provided by the MLF is desirable in reds. Whether the MLF is done in tank or barrel is one of the variables here. It’s less effort in tank, as the process must be individually controlled in each vessel. Oak barrels are smaller, so it is a time-consuming process, but the advantage is MLF in barrel creates a softer, rounder mouthfeel.

Osmosis is essentially water molecules passing across a semi-permeable membrane from the side of higher water molecule concentration to lower water molecule concentration. Memories of curly raw potato chips in school science lessons suggest the concept of osmosis, and thus reverse osmosis, shouldn’t be completely alien.

Clearly osmosis is not good for wine or grape juice – they would become diluted. But there are three decent reasons to reverse the passage and selectively take bits out of wine:  

1. Your vineyard is in a cool climate; you’ve had to wait till rainy late autumn to harvest because that’s when the sugars and phenols (tannins, colour etc) in the grapes are ripest. If wet grapes go straight to winemaking, all that rainwater dilutes the fruit.
2. Your vineyard is in a hot climate. All the grape sugars are ripe, and continue to accumulate, but the phenols take longer, which means, the wine has ripe tannins, but shed-loads of alcohol too.
3. Volatile acidity (VA): stuff that’s brilliant at adding complexity and lifting aroma in small doses, but smells like nail varnish remover and vinegar in larger quantities which is a major fault.

The ‘reverse’ bit of osmosis is achieved through high pressure and it separates out different bits of juice or wine in the opposite direction to osmotic flow across a selective membrane. The liquid going through the membrane looks pretty much like water; the winey bit stays on the original side of the membrane. Water is the smallest molecule in wine and passes readily through the membrane. So you whiz some of the wet grapes through an RO machine before the fermentation starts.

When dealing with high alcohol wine, water goes through the membrane, and so does ethanol. The water/ethanol mix is distilled to separate the two.  The watery bit can be added back to the wine to keep the original concentration while the alcohol is removed.  (If the alcohol is added back and the watery bit removed, this increases the alcohol content of the wine).

The molecules responsible for VA are also quite small and can pass through a selective membrane, along with water and a few other things. This mix is treated in a different way to remove the offending acetic acid, and what remains of the mix is returned to the winey portion. Et voilà.

Yeasts are the little gods of wine, fermenting grape juice to that illustrious liquid.  Winemakers can exert a little influence by choosing ‘cultured’ yeasts (come in packets) over ‘indigenous’ (a combination of ‘wild’ and ‘wine’, from the vineyard environment) ones, depending on the aim, but the importance of being yeast has moved way beyond the simple conversion of sugar to alcohol. There are around 400 aroma substances in wine influenced by yeasts.  

There are a whole bundle of different yeast strains which behave slightly differently during fermentation and they therefore produce wines with different characteristics. The ‘cultured’ ones have been bred in a laboratory specifically for certain traits, both production- and style-related. These include efficiency, so converting less sugar to more alcohol, the ability to resist high pressures for sparkling winemaking, the ability to ferment at very low temperatures to preserve delicate primary fruit characters, or for the delivery of certain aroma profiles. 

Cultured yeasts are added to newly harvested juice. A single strain of yeast is usually chosen with a specific character, although some manufacturers also produce packets of blended yeasts with combined properties. In addition to any specific character trait, cultured yeasts are predictable and consistent – the brands of the yeast world.

‘Wild’ yeasts hang out all year round with ‘wine’ yeasts in the vineyard and winery corners, waiting for the juice to become available. A whole gang of different yeast strains is implicated in a wild ferment, each with their own character, sometimes clubbing together to bring flavours that they couldn’t bring individually, for example helping to liberate floral and citrus flavours from flavourless precursors during fermentation. And as the fermentation continues, there is a changing cast of characters having a dominant influence each contributing their own little bit.

But wild ferments are much less predictable, more risky, they can produce funky flavours, they may not ferment to full dryness, they may take longer, and they can build character and individuality into a wine.

What’s that all about, and if white wine comes from white grapes, and red wine from red grapes, where does pink wine come from, given there aren’t really any pink grapes?

In the pink

In the first instance, rosé, or pink, wine offers all the bright, refreshing, crunchy characteristics of a (usually) un-oaked white wine, plus some of the rich berry fruit flavours of red wine. They are ideal for summer drinking, with summer and forest fruit berry flavours, yet without the grippy tannins that are typical (and essential) in most reds.  But they also have a year-round appeal that we have finally cottoned-on to.

As an aside, there are some reds that suit chilling well, but chilling tannic wines accentuates the tannins, so for cool, tasty wine, pink can be a great unifying factor.

Along with the growth of pink production has come great stylistic diversity. Style varies from the medium-dry/medium-sweet white grenaches and zinfandels from the USA, and many wines from all over the world labelled ‘blush’, to bone dry, serious aperitifs or even food-demanding styles, often from parts of France such as Provence in the south and Tavel in the Rhône valley. Everything exists in between these two extremes.  

In the second instance, the way pink wine is made is protected in the European Union (EU). Within the EU rosé wine must NOT be made by blending red and white wine together. 

Blending red and white is allowed in non-EU countries, and those wines can be imported into the EU, but rosé wines made in EU countries have to be made by a traditional method.

The only exception to this rule is in Champagne, where rosé Champagne can be made by blending white and red wines together.

Apart from the Champagne exception, in EU countries, pink wine must be made using ONLY red grapes. Colour compounds are found in the skins of grapes, which is why rosé wine cannot be made from white grapes. Rosé wines must be made by the bleeding, or saignage, method.

By macerating grape juice and skins (after crushing the berries a little just after harvest) for a shorter to longer period of time, less or more colour is extracted from the skins. For a very pale rosé, red grapes may be pressed directly – a bit of a squash and some colour comes away from the skin (vin gris). More usually skin and juice is macerated from a few to several hours, after which the coloured juice is drained off (bleeding/saignage) to continue its fermentation as for a white wine (i.e. without skins).  Judging the desired colour of the finished wine before it has fermented is a skilled and complex job.

Red grapes macerating in their juice

Globally nine out of ten bottles of rosé are made by this ‘bleeding’ method, using just red grapes. The poshest French pink wines such as those from Provence and the Rhône’s Tavel, are made by this maceration method.  Indeed pinks from Provence account for 5% of all rosés made in the world.

Merely blending red and white wine together to make pink is by comparison very simple. But because so many new world countries allow it, there was a proposal in 2009 in the EU to allow this blending option for production in the EU, in part in an attempt to increase the competitiveness of rosé wines from EU countries. 

The proposal did not succeed because the three biggest global wine producing countries, France, Italy and Spain, led a successful lobbying campaign to prevent it, arguing that blending red and white to make pink belittled their traditionally made products and would lower the quality of rosé wines. Their argument won the day, so EU pink wines continue to be made by the ‘bleeding’ method. Given that France alone makes nearly 30% of the world’s pink wine, its voice was bound to carry some authority.

One more thing about rosé wine.  Freshness is key to pink wine. They are generally made for young drinking (though there are exceptions to this rule).  A large part of the joy about drinking pink is the freshness, the vibrancy, the brightness of hue, indeed the youth of them.  This also feeds in to the original summer-drinking idea.  The northern hemisphere harvest is in Sept/Oct, so by the time the wines have finished fermenting, settled over winter they’re at their peak of freshness as summer emerges.  It’s a similar pattern in the southern hemisphere with harvest in Feb/March/April…

Minerality in wine is one of the trendiest tasting terms of our times. Science is establishing that it does exist, at least sensorially, but identifying potential responsible compounds or complex of compounds working in combination, and that can be chemically analysed, remains elusive at best.

No minerality directly from rock

Professor Alex Maltman of the Institute of Geography and Earth Sciences at the University of Wales, Aberystwyth explained: firstly “there is a whole series of complicated ways in which the parent geological minerals decay to yield nutrient minerals”, and “for roots to pick up nutrient minerals, such as potassium and calcium, these elements have to get into solution. Then there is a whole series of complicated ways of those elements getting into the vine roots – a complicated series of distancing reactions between geological minerals and getting nutrients into the vine.

No route from root to wine

“When you start making wine, yeast takes some of those nutrients from the fermenting must, making the connection between mineral nutrients and geological minerals even more remote and complicated.”  He added “whatever minerality is, it is not these elements that ultimately came from the vineyard. They’re last in all the things that give wine its flavour.”

With minerals comprising just 0.2% of wine, Maltman said you cannot taste the minerals, especially with all the organic compounds that do give wine its flavour.  

Semantic confusion

Though, Maltman explained, “I’m not saying the taste attribute doesn’t exist in wine. But it’s given the label that gives a connotation of origin, of coming from vineyard. People used to talk of austere, lean, steely, even. As soon as people say minerality, people assume minerals are in the wine.“

To geologists minerals are complex compounds – collections of minerals/elements bonded together, such as feldspar. To nutritionists minerals are single elements – zinc, calcium, potassium.  To wine people minerality seems to elicit a direct causal link with vineyard rocks despite this being an untenable thesis.  All of which creates confusion: of description, of accuracy, of communication.  This is not to say that soil, geology, drainage and water holding capacity are not important influences on the flavour of wine.

Mosel slate

Which leads us back to minerality by association: this is Mosel riesling therefore I’m tasting slate’ or ‘this is Sancerre therefore I’m tasting gunflint’.  Minerality has relatively quickly become a literal and emotive ‘beam-me-up Scotty’ of rocky allusions which create vinous illusions.

Winemakers’ words

Even winemakers worry for words when trying to explain the ‘minerality’ in their own wines. The ‘reductive’ sulphide connection is often mentioned, as well as other perceptions – a palate texture, tension, tautness, a tingle on the tongue, a cleanness, purity and freshness, an integrative feeling.

Dr. Tony Jordan, of global consultancy Oenotec, said minerality is a “taste sensation. People have talked the talk in the last ten years. It’s one of the buzz words, everything has to have minerality. I tend to associate it with wines that have a finer, tighter, long flavour spine, good spice,  that have a distinct play of acid in the balance; occasionally an effect of sulphide, and may even be other chemistry in the wine, both organic and inorganic components.”  

This relationship with acidity is a common thread. Martin Aurich, general manager of Weingut Unterortl in Italy’s Alto Adige said: “minerality is a certain amount of acid, acid which is not sour; a positive acid which requires another sip. It’s like a game in your mouth – acid, tannin, sugar.”

Bevan Johnson, managing director of family winery Newton Johnson in South Africa described minerality as “the poise of the finish. It brings a freshness from the mid palate to the finish; a freshness that’s not just acidity. A harmonious finish that’s fresh.”

Pfalz basalt

And Ernie Loosen, of the Mosel’s Dr. Loosen, was emphatic, saying “minerality always has something to do with acidity. Acidity expresses minerality, just as sweetness brings out aroma structure in our wines; as alcohol carries the aroma. A wine without acidity doesn’t show minerality as strongly as wine with the right amount of acidity.”  

At Loosen’s JL Wolf estate in the Pfalz, when they taste the wines blind “with its black basalt soil the Pechstein is the most mineral driven. It is more grippy, with a stony edge.  The Ungeheuer, with its loamy, weathered sandstone soil, is softer even with the same analytical acidity. Minerality is the acidity and soil together. At the end of the day you can only describe minerality by tasting it.”

Cooler climate

If the acidity thesis gains ground, must minerality be a cooler climate phenomenon?  Loosen said he saw less minerality in the hot 2003 than the classic 2007 German vintage.

Climate change specialist Professor Gregory Jones, of the geography department at Southern Oregon University, agreed, saying “grapes grown in cool climates tend to express themselves differently than those grown in warmer climates. Also, cool climate wines are much more likely to be single variety wines than the blends we find in warmer climates. Single variety wines grown at or near their cool climate margin will always show more finesse and character than those grown in warmer climates. A good example is chardonnay, which is grown in cool to fairly warm climates. In a warmer climate there is less finesse and more need for oak to bring out other characteristics. Also a good test is to try the chardonnays grown in the same region in a cool versus a warm vintage … the warm vintage will lack the supposed ‘minerality’ and finesse. So climate does play a role.”

Priorat schist

But what about places such as Priorat, where notes of minerality/graphite are commonly reported in the wines?  This is a warm to hot Mediterranean climate where big, alcoholic, blended reds are made. In his inimitable style, Alvaro Palacios of his eponymous Priorat property said “minerality is exactly as you see in the slate or granite soils. There are huge levels of minerals and metals. When you lick them you can feel that. Vegetal tannins are normally very fat, and mild, gentle, soft. Minerality is different; something tiny and vertical that dries out, micro particles.”

Over at Celler de Capçanes, in neighbouring Montsant, winemaker Jürgen Wagner upheld the acidity paradigm, saying “minerality adds some astringency. It gives a feeling of a higher level of acidity. It is a certain saltiness, the graphite of lead pencil for me means nerviness, liveliness, even astringency.”  

Scientific speculation

All of which means we are left with supposition and suggestion.  Jones suspects “there are chemical pathways via fruit to wine transformation that create aroma/flavour components that spark sensual characteristics that lead us to our cues of certain, remembered qualities.”

Maltman makes it clear he doesn’t know “what minerality is actually due to. I think acidity in wine is relatively well understood so I’m not sure it’s primarily that; my guess would be some combination of organic compounds (secondary metabolites), possibly, as has been suggested, involving sulphur” adding “complex organic molecules could be influencing minerals, promoting some, and buffering others. The effect could be important. I’m saying you cannot taste vineyard minerals. But these tiny amounts could have a chemical role. “

But we are left with more than poetic allegory. Jean Trimbach, of Maison Trimbach in the Alsace, said: “It is there. It exists. It’s the philosophical part of the wine; the most intellectual part of the wine, which has yet to be better analysed, and quantified.”  

Wine needs the scientists to get a hurry-on, so we can use the term correctly and consistently as a meaningful communicator of wine quality, composition and style.

But what about using a small proportion of ‘good botrytis’ in dry white wines, notably riesling but not restricted to this variety? So-called ‘good botrytis’ because it is the same mould as that which causes grey rot/bunch rot/bad botrytis, where infected grapes must be thrown away because they give a rotten fruit taste to wine.

Bunch with healthy grapes and botrytis-affected grapes

There are two schools of thought on this issue, which Roman Horvath MW, the managing director of Domäne Wachau outlined for the Wachau region of Austria, saying some producers, such as “Franz Hirtzberger work with botrytis. I call them the masters of botrytis. There has to be a very exact picking time, almost with half-day precision. And with even more picking passes through the vineyard. Others, such as Rudi Pichler, focus on elegance, minerals, purity and precision. We are more on the side of Rudi Pichler and Alzinger.”

Indeed for the 2009 vintage Mathias Hirtzberger of Weingut Franz Hirtzberger said “usually we use 5 to 10% botrytis. These are wines for 10 years’ ageing, and our smaragds will age for much more. The wines have a lot of alcohol, acid and sugar as we aim to harvest the grapes very ripe.  It’s always about the taste.”

Such use of ‘good’ or ‘dry’ botrytis usually results in wines of higher alcohol, 14 to 14.5%, rather than 13 to 13.5%. The wines are more concentrated, with greater weight, though not necessarily with more residual sweetness to them, as this is likely to have been fermented out. Lucas Pichler, the winemaker at Weingut F.X. Pichler explained further, saying with good botrytis you get “more deepness, more extract, especially for riesling. It’s not so important for grüner veltliner because you lose a bit of the pepperiness of grüner veltliner.”

It’s this potential masking effect that deters other producers. Leo Alzinger of Weingut Alzinger explained “we use dry botrytis as little as possible. The wines are more focused without botrytis. They are more reflective of their terroir. Wines start to age after one year with botrytis. And with more botrytis there is more alcohol, plus aromas which cover the terroir.” 

Cleanliness of fruit and precision of focus are important drivers for ‘no-botrytis’ proponents. Also in the Wachau, Peter Veyder-Malberg of Weingut Veyder-Malberg said “botrytis destroys the character of the grapes and the character of vineyard.  With riesling, when I see bunches start with botrytis, I cut the whole bunch and make the wine, leaving other [completely healthy] bunches on the vine. Three weeks later I can harvest sound bunches. But it means I harvest quite early.”  He added “I tell my workers to select each berry which they would choose not to eat and throw it away.” 

Wachau vineyards close to river Danube

The ‘to B or not to B’ question appears most pertinent for the Wachau, at the western, coolest extreme of Danubian viticulture in Austria, where the vineyards are close to the river and botrytis is more likely to creep into the vines at the end of the growing season.  Horvath said “botrytis is part of the microclimate here [Wachau] in October. You can’t avoid it.”

Almost next door to the Wachau, in Kamptal, where the vineyards are a little bit further from the mist-creating river, said Willi Bründlmayer, of Weingut Bründlmayer, “Kamptal has a tradition to work without botrytis.”  Though he’s not dogmatic on the question, adding “In 2001 we harvested with botrytis because it was a high acid year and the botrytis softened it out to balance the wine. Normally it’s not our style [to use botrytis]. I like straightforward, clean grapes.”

Bründlmayer also believes botrytis masks terroir effects saying “It should taste like riesling, like Heiligenstein, like the vintage.  Botrytis gives complexity, makes you a winner in a blind tasting, but if you want to drink the wines, then you need no botrytis.” 

Fellow Kamptal vintner Weingut Hiedler has moved away from this winemaking style. Maria Angeles Castellanos-Hiedler said “we used to use dry botrytis. In the last five years we’ve refined the winemaking and now try to have as little as possible. We like to have clear wines.  The botrytis means the wine is not ‘quiet’, it tastes very spicy. We want clear and clean tastes.”

This theme was picked up by Johannes Hirsch of Weingut Hirsch, who said “botrytis lays over the terroir, it hides typicity”, adding “petrol notes come earlier with botrytis.”

The subject came up at a May 2010 Global Riesling tasting in Vienna, hosted by the Institute of Masters of Wine. Rowald Hepp, managing director of Schloss Vollrads in the Rheingau region of Germany, said “botrytis can add complexity in dry riesling, but makes it more difficult to keep single vineyard expression. Terroir and botrytis is a tricky pairing. We avoid it in our dry wines.”

Ultimately the use of dry botrytis is just one winemaking option with a resulting style outcome. If the complexity imparted by botrytis adds layers of interest, dimension and texture to a wine that the drinker enjoys, it doesn’t matter if terroir or even varietal character is obscured. Some would argue terroir obscures varietal character. It depends on what the winemaker wants to achieve.

If the wine is tasty, job done, with or without botrytis.

French oak from centuries-old forests has asserted its dominance in the wine world with aplomb and skill as well as price premium, but it wasn’t always thus. The Bordelais used to be more than happy with Hungarian and Baltic oak, and a comeback for non-French wood is being quietly asserted. 

It is over the last quarter of a century that oaks from the same species as French – Quercus petraea (sessile oak) and Quercus robur (pedunculate oak) – from other European forests have been making a return into the wine world, especially those from the post-communist world. Other woods, notably cherry and acacia have long been used in traditional European wine making.  American oak is from a different species (Q. Alba) and is not considered here.

French oak barriques

This resurgence is not a question of economics. Research at the Australian Wine Research Institute (AWRI) by Mark Sefton et al. found that the geographical origin of oak for barrels resulted in differing amounts of flavour compounds in wines. Though the only Q. robur (a.k.a. English, French, Russian etc.) studied were from different regions in France, it’s not far-fetched to make an extrapolation for flavour difference to different zones and climates outside France.

The origin of species: Hungary, Russia, Slavonia

While both Q. robur and Q. petraea are grown throughout Europe, including mixed forests in France, there is more Q. robur further east, though some areas also have concentrations of Q. petraea. Jean-Pierre Giraud, commercial director at Taransaud cooperage, whose owners Chene & Cie have a joint venture in Kadar Hungary, explained “sessile is what we consider medium to tight grain and pedunculate is medium to wide.”

But the two species tend not to be separated in the cooperage process. Geographical origin and quality of the oak are more important than the species of oak. Giraud said “The Hungarian oak trees where we source at Kadar are smaller in diameter because they age in the hills in the east of Hungary, in Tokaj, in a continental climate.  This oak gives structure to the wine, with elegant tannins and spicy toasted bread.”

In southern Hungary, the Trust Hungary cooperage has been working since the early 1990s. Their managing director, James Molnar said: “Hungary sits in the Carpathian basin, between the mountains of Austria, with Slovakia to the north and the Ukraine to the east.  Warm airs come over the Adriatic giving a Mediterranean climate in the basin. As you leave the Carpathian basin, the chemical and physical characters of the trees change, with smaller trees as it gets colder to the north.

Big, old oak casks

“Hungarian oak has higher levels of eugenol compounds than French – nutmeg, clove, oriental sweet spice characters.” He added “if I’m in a blind tasting, I usually look for mid palate weight. Hungarian oak generally adds a rich sensation of weight and texture in the middle of your mouth.  I find French oak has more breadth in the mid palate.”

Even earlier onto the eastern scene was Seguin-Moreau in the late 1980s. They use Russian oak from the Caucasus – the north east corner of the Black Sea – which also has a more continental climate than France.

Research by Andrei Prida – prior to his current role of research and development manager at Seguin-Moreau – and Jean-Louis Puech at INRA-Montpellier (National Institute for Agronomy Research) found that the “most important features for distinguishing origin [French versus Eastern European] were volatile compounds including eugenol, 2-phenylethanol, vanillin, and syringaldehyde, which give a slightly spicy, mild vanilla aroma.”  Prida added “we observed forest effects more when we consider remote sourcing. So we talk about French, Eastern European (Russian, Bulgarian, Romanian) and Caucasian – zones separated by hundreds of kilometres.”

Prida said: “We observed that Caucasian oak is characterised by moderate tannin and aromatic impact. This oak allows winemakers to obtain fresh and mineral wines, while generic Eastern European oak is mostly well suited for wines which require big tannin impact; it’s good for building wine structure. But we cannot say one is more valuable than another, and the choice is mostly related to the profile of wine and oenological results needed“.  

Rioja producer Marques de Vargas was one of the early trial partners, in 1991, using Russian oak from Seguin-Moreau. They were so happy with the results that they created a new wine – Marques de Vargas Reserva Privada, made in very good vintages, and made using 100% Russian oak barrique size [225 litres].  The winery’s winemaker, Francisco Javier Pérez Ruiz de Vergara, said: “The Russian oak gives different aromas [from French oak] during the ageing, more elegant and sweeter aromas.”

Over on the north-west side of the Black Sea, a swathe of forested territory continues along similar latitudes, and now comprises Romania, north-eastern Croatia, Hungary and Austria.

This is Slavonian oak territory – a staple of traditional European winemaking. According to the FAO (Food and Agriculture Organisation of the United Nations), Slavonian oaks of the Danubian plains of ex-Yugoslavia (part of Hungary before the first world war) are of very high quality. Bosnia and Croatia equally split the majority, with the rest divided between Slovenia, Serbia and Montenegro.  They suggest the best quality Slavonian oak comes from the north-eastern plains of Croatia.

Slavonian oak is widely used in the traditional and classic Italian wines of the Veneto, Tuscany and Piedmont.  Respect for the fruit by Slavonian oak was top of the list for Amarone producers. Riccardo Tedeschi of Agricola F.lli Tedeschi said: “Slavonian oak has a less fine grain [than French], which is fine for big barrels; it’s more consistent over time, at least two years. We use 25-50 hectolitres (hl) for Amarone. It gives a less intense flavour than French oak, sweeter aromas, less structure than French. As our grapes are delicate, bigger oak is gentler.”  Luca Speri, of Speri Viticoltori, added “with Slavonian oak, micro-oxygenation is long, and the wine needs time to be ready. And with Slavonian oak, the wine can live longer in the bottle.”  

For their Amarone, the Allegrini family pursue a mixed French/Slavonian oak philosophy, as Marilisa Allegrini explained: “our Amarone goes to new French barrique for 18 months.Then the wine is finished in old, 80 hl, Slavonian oak for 7 months. Slavonian oak breathes and integrates the French oak into the wine, and it eliminates the variation between the oak barriques. We don’t use stainless steel because it gives bitterness. “

In Tuscany, the blending and integration facility of Slavonian casks is also valued at Felsina, where Giuseppe Mazzocolin said “we use Slavonian oak for our Chianti Colli Senesi and Chianti Classico, since their main qualities are their drinkability and the refreshing crispness of a young sangiovese. Slavonian oak has a beneficial effect on the wine’s structure,” adding, “please keep in mind that we work predominantly with sangiovese, [which is] technically temperamental. It consistently requires a light hand on the oak.”

Optimising the use of oak for micro-oxygenation properties rather than oak characters continues to be important where fruit, rather than ‘boisée’ characters are sought.  Mazzocolin said “We place great importance on employing barrels that have been used in preceding years, since the wine that has been in them has lent them certain characteristics that reflect the Felsina terroir. They are excellent up to the third or fourth usage, and in this respect Slavonian oak gives us better rotational effectiveness.”  

North east Italy neighbours Slavonia. Here, at Tenuta Manicor, proprietor Michael Count Goëss-Enzenberg, said: “The advantage we see in our oak is, besides the harmony with our wines, that it is very subtle on our fruit, and on the aromas and the minerality our wines show. It just respects the character of our wines more.”

Cherry and Acacia

A little further west still, and cherry and acacia wood are added to the mix, offering something entirely different to European oaks. Marinella Camerani, owner of Azienda Agricola Corte Sant’Alda, near Verona in northern Italy, uses cherry wood for her Valpolicella Ripasso, because of its traditional use for wine ageing and because “the Ripasso is a traditional wine of our area. The cherry wood is less invasive on the wine, it doesn’t cover the taste and flavour with vanilla. It gives just a little bit of cherry taste to the wine without covering or hiding natural flavours.”

Who knows if it’s chicken or egg, but cherries are the third most important crop after vines and olives in the hills around Corte Sant’Alda. It’s not a question of price though. Camerani said “cherry wood is 30% more expensive than French oak.”

Staying in the Veneto, Stefano Inama, of Azienda Agricola Inama, uses acacia wood on his dessert wine Vulcaia Après, which is made from sauvignon blanc, having eliminated French oak in tasting trials. He said: “we use it because it has a beautiful sweetness. Acacia has no tannins, it’s perfect if you want to make a wine which is particularly elegant, with finesse, and which doesn’t need extra tannin, such as a fine white dessert wine.” And not much is new, about 20%, which Inama said makes little difference, apart from “more acacia notes, more acacia flowers, acacia scent which melts into the wine.”  But he added: “I wouldn’t use it for other wines because there’s too much sweetness, and you get into sweet and sour flavours.” 

Acacia is also relatively popular in Austria, with the likes of Sattlerhof and Tement in Styria, and Bründlmayer, Schloss Gobelsburg and Hiedler in the Kamptal using it.  Ludwig Hiedler said: “For Austrian whites like grüner veltliner, riesling and weissburgunder, with their spicy taste and lively acidity, I like to work with acacia wood, which helps to increase these unique and authentic characters of the wines.” He added acacia wood has “soft tannins with a sweet and more neutral taste” compared to the “tannins of French oak [which] are stronger and the wood/oak flavour is more present.”

Size does matter

French and Hungarian oak may focus on the 225 litre barrique, but the advantage of larger oak tanks for fermentation and storage is that there is some thermal inertia, although internal temperature control panels can also be used.  The low level micro-oxygenation reactions help to polymerise tannins and avoid reductive flavours developing during ageing.

Sometimes though, the choice of size is less romantic. Camerani’s choice of 15 hl barrels is dictated both by space in her traditional cellar and the quantity of ripasso she produces.

Hiedlier uses 1,500 to 2,500 litre acacia casks, saying “The bigger size is better for a perfect micro-oxygenation.” For the past four years Hiedler has fermented his wines spontaneously.  Because of this, he said; “the fermentation goes over a longer period than with cultivated yeast and needs more oxygenation. This micro-oxygenation is perfect in wooden casks. And the typical flavours of our wines have no competition with stronger tannins or wood flavour.”

So cherry and acacia evoke eponymous aromas; Slavonian oak respects the fruit, and Hungarian and Russian oak offer varying degrees of tannic modesty. And for all these woods, casks larger than barrique are favoured for micro-oxygenation and their exceedingly modest oak-flavour.  Respecting and supporting fruit flavour rather than adding oak flavour are the modern stylistic priorities.

Los Lingues vineyard

The Casa Silva study came about because the family-owned and run company wanted to understand why they had the same grape variety in the same climate but they were getting quite different wines.  They wanted to explain this variability so the knowledge could be used to grow grapes better matched to the style and quality of wines they wanted to make. 

And they’ve discovered that even very small distances in the vineyard can produce different results in the wine, which is making them re-evaluate what they plant and how they manage the vineyard on a micro-scale.

How it happened

The research project was started in 2005, by Casa Silva’s technical director and chief winemaker Mario Geisse, in conjunction with Professor Yerko Moreno of the University of Talca, where he is the director of grape and wine research, specialising in viticultural issues including clonal selection. 

They started looking at small ‘terroir units’ of 0.1 to 0.5 hectare with an aim to identify the pre-requisites for growing high quality carmenère in Colchagua.

Prof Moreno in a soil pit

They investigated crop load (the weight of grapes per vine), vegetative vigour (foliage), as well as the soils, which have all been brought down from the Andes over the last 300,000 years, and contain more or less rock, depending on location.  Professor Moreno said the team identified “small terroir units for carmenère, cabernet sauvignon, viognier, syrah, petit verdot, considering climatic conditions, topography, soil composition and origin, vine rootstock, variety and clone, and viticultural managment.”  He said they dug hundreds of soil profiles, describing them for chemical composition, water holding capacity, rooting capacity, which allowed them to separate areas into different units, broadly along the lines of sand, limestone and clay.

They measured growth parameters of the vine, including the vegetative canopy and yield, and related this to bunch shade/exposure. Moreno said: “If you have a grape cluster that is too exposed under our conditions, you can cook the berries. It’s completely different from areas of cooler climate. It can reach up to 45°C in our valley.” What they found was that sunny berries had lower colour, harder and drier tannins. 

Then they did lots of small batch winemaking and carefully analysed the resulting wines, creating a virtual warehouse of vineyard and winery data.  Once they started to sort out some of the effects, Moreno said “One of the most important for me was the water behaviour of plants. Cultivars have different responses to stress – syrah copes with more stress than cabernet sauvignon. And vines of the same cultivar behave differently in different sites, and within one season.”  He added “cabernet sauvignon with severe water stress produced more astringency in the wines, the tannins were too harsh.  And if there was no water stress, we tended to have similar problem – the tannins were too harsh.” 

But on carmenère the results were different. With no water stress there were “green characters.  We got some dry tannins with increased water stress, though not as much as cabernet sauvignon.” He explained “the best expression of carmenère was achieved where the plant had to explore greater soil volume to get its water supply, at least one metre deep.”

The results of this research are enabling Casa Silva to replant areas of vines. Moreno said: “I would change the way the vineyards are planting, not the direction of rows. This project is aiming to produce high quality wines, the variabilities are subtle.  New plantings are being done considering the soil.” Combine this with tweaking vineyard management to realise more potential from their grapes should enable Casa Silva, Geisse said, “to get the best possible quality wines” from each plot.

The research also revealed quite marked genetic variability in the carmenère vines, so Casa Silva recently embarked on new research into carmenère clones to identify those that produce better quality fruit for high class winemaking.

The first article looks at where the scientists are at with minerality.  The second one speculates scientifically, if such a thing is possible.

What follows are some thoughts of winery people I have quizzed on my various research visits, along with dates, so the comments can be put into the perspective of our evolving knowledge on the subject of minerality in wine.  These comments are unfined, unfiltered, uncategorised, not that we yet possess the knowledge to categorise minerality.
 

A few developing themes, make of them what you will, not all highlighted in the following quotes, include

• linking minerality and acidity.
• linking minerality and ageworthiness.
• linking minerality and (bed)rock.
• linking minerality and complexity.
• linking minerality and freshness.
• linking minerality and tannin.
• linking minerality and terroir.
• suggestions that not all grape varieties have the potential to express minerality.

Olivier Humbrecht, Domaine Zind-Humbrecht, Alsace, France. November 2009
“You cannot smell minerals as they are not volatile. Salt is associated with other molecules, for example iodine, which is volatile.  Minerality is more a palate sensation than an actual smell.  If a wine is going towards more undergrowth, earthy, it goes to more mineral. The brain does not associate fruit with minerality.”

Minerality “leaves your palate more salty than sweet. And it’s more difficult to see it on sweet wines than dry wines, as sugar will hide it.  Also the tannins of oak will cover or overpower a sense of minerals on the palate.”

It’s a “sensation on the palate.  You can also sometimes detect it in a way of pH. Acidity potential might reflect how minerals have reacted with the wine.  A higher pH, if not caused by a fault, such as rot or dilution, for me, is that soil is more present in the wine. The more minerals in the wine, pH increases.”

Wolfgang Klotz, marketing and sales manager at Cantina/Kellerei Tramin, Alto Adige, Italy, November 2009.
“If I smell stony, chalky, and stones banging together, and the wine is dry and crisp, this I think of as minerality.  The topsoil is chalky, and 1-2 metres below is volcanic porphyry.  Porphyry gives lot of minerality. You could age wines up to ten years and more.”

Klaus Gasser, sales director at Cantina/Kellerei Terlan, Alto Adige, Italy, November 2009.
The mountain “Tschögglberg is porphyry, a quartz porphyritic rock, high in minerals, with a high silicate concentration, like in Pouilly-Fumé with silex. There’s a high mineral concentration in the soils. Minerality in the wines is a salty note, and great ageing potential.”    

Martin Aurich, general manager at Weingut Unterortl, Alto Adige, Italy, November 2009.
“Minerality is a certain amount of acid, acid which is not sour; a positive acid which requires another sip. It’s like a game in your mouth – acid, tannin, sugar.”

Franz-Joseph Loacker, sales manager at Tentute Loacker, Alto Adige, Italy. November 2009.
“Minerality comes from the stones and from the power of the soil, from the terroir, and what we have in the soil. Some grapes such as sauvignon blanc have minerality; other grapes do not, such as gewürztraminer, which goes more in the sweet direction.”

Willi Bründlmayer of Weingut Bründlmayer in Kamptal, Austria, June 2009.  
“In spring, the terraces are soaked with rainfall. Water remains hidden in clefts of the rock, and takes up minerals. Vine roots need water. But the taste is something different.  For me, the wines are not too alcoholic, they lack creaminess and softness. I feel a slight roughness, a substance and structure but different from the substance and structure tannins give.”

Hannes Hirsch of Weingut Hirsch in Kamptal, Austria, June 2009.
“Minerality is like an extra layer of Maldon sea salt, which bubbles and explodes on your tongue. Heiligenstein has a smokey nose, like banging stones together.  As grüner veltliner  and riesling wines get more powerful, they lose their fruit definition. Minerality comes through as a tension on the tongue.”

Andi Kollwentz of Weingut Kollwentz-Römerhof in Burgenland, Austria, June 2008.
“Minerality comes from the soil but it’s not a chemical influence, it’s a physical influence, it’s stoney. If you get the grapes in the right state, and you don’t interfere with the wine in the cellar, you get an impression of minerality: fine, fragrant fruit, but not bold, and a spiciness, not from oak.”

Alvaro Palacios of Alvaro Palacios in Priorat, Spain, April 2009.
“Minerality is exactly as you see in the slate or granite soils. There are huge levels of minerals and metals. When you lick them you can feel that. Vegetal tannins are normally very fat, and mild, gentle, soft. Minerality is different. It’s something tiny and vertical that dries out: micro-particles. It’s a blend of tannin and minerality.”  

René Barbier of Clos Mogador in Priorat, Spain, April 2009.
For Barbier, minerality “is all to do with terroir.” Of his Clos Manyetes wine, he said the “wine is built on the basis of terroir; the minerality and tannins are interwined. When wine is created on a more technical basis, the tannins are clearly defined. With terroir and minerality the tannins are intertwined.”

Sara Pérez of Mas Martinet in Priorat, Spain, April 2009.  
“Minerality in Priorat is complicated to understand sometimes. Minerality is all the aromatic components of the soil – liquorice, iron, non-organic things that you can find in wine. You never have liquorice or iron on calcareous soil. The floral and fruity elements are the climate and the grape variety.”

Jürgen Wagner, winemaker at Celler de Capçanes, Montsant, Spain, April 2009.
“Minerality adds some astringency. Minerality disguises. It gives a feeling of a higher level of acidity.  It is a certain saltiness; the graphite of lead pencil. For me it means nerviness, liveliness, even astringency.”  

Duncan Savage, winemaker at Cape Point Vineyards, South Africa, March 2009.
“Minerality is the most abused tasting term. It’s a perception, an holistic picture. You identify with the soil, and feel like you’re tasting what you see in the soil. This is minerality by association.”  

Neil Ellis of Neil Ellis Wines, South Africa, March 2009.
“Minerality is a term to describe a certain feel in a wine, not massive, not big, more elegant. On chardonnay I use ‘restraint’.”

Andrew Gunn of Iona, South Africa, March 2009
“Minerality is flintiness, wet stones, chalk rocks.”

Bevan Johnson, manager of Newton Johnson Wines, South Africa, March 2009.
“Minerality is the poise of the finish. Minerality brings a freshness from mid palate to the finish; a freshness that’s not just acidity. An harmonious finish that’s fresh.”

Anthony Rawbone-Viljoen of Oak Valley Wines, South Africa, March 2009.
“Minerality is a product of the soil, and is something at the back of the wine, a flintiness, a complexity lurking at the back.”