Guaiacol and 4-methylguaiacol are the main compounds involved.  But they also occur commonly in wines aged with toasted oak, so are, to a certain extent, desired in some wine styles – toasted, smoky flavours are deliberately sought, especially in red wines.

The smoking of certain foods is big business where smoky flavours are actively sought. And the specific smoky flavours differ according to the fuel origin – beechwood imparts different flavours to oakwood.  And where would the barbecue be without smoky flavours? 

Bush fire smoke over Simonsberg in South Africa, 2009

In 2003 in Australia, thousands of tonnes of grapes were downgraded or rejected, amounting to an estimated AUD$7m. Research carried out in the heat of those burns provides the basis of our understanding of the issue. 

What is smoke taint?

Smoke taint, though, suggests a presence of these compounds, and likely others too, that has not been deliberately sought by winemaking. They can be identified by an ‘excessively dry back palate character and a lingering retro-nasal ash character’ according to Australian Wine Research Institute (AWRI) research, and it is Australia where much research is being done.

Bush fires occurring near vineyards are known to cause contamination of the resulting wine.  It first came to serious attention after the 2003 Australian vintage, where industry services dealt with a lot of grapes and wines tainted by smoke flavours.  During January and February 2003 there had been a lot of bush fires in Victoria and southern New South Wales.

Smoke taint was observed in both grapes and wines. 

Given the number of incidences, trials by the AWRI examined the issue during the vintage period, the main findings of which were:

• samples exhibited characters of smoky, burnt, ash, ashtray, salami, smoked salmon, etc.
•  guaiacol and 4-methylguaiacol were the main compounds implicated in the taint.  Both these compounds are regularly found in wines matured with toasted oak. An additional back-palate drying and ash note was found in contaminated samples.
• These compounds are thought not to be the only ones contributing to the taint. When control samples were spiked with guaiacol and 4-methylguaiacol, the sensory effect was less marked than in smoke-affected samples. 

Possible ‘vineyard washing’ remedies were trialled to reduce guaiacol concentration in the grapes, but none of the options reduced the concentration in juice or crushed grapes.

Concentration of the compound increased with increasing time of maceration of juice with skins.  This was consistent with anecdotal evidence of taint being worse in machine-harvested fruit and in pressings.

These compounds were found to reside in the skins of grapes.

Tests were done to see if was possible to reduce the taint during winemaking, for example, by using fining agents to ‘scalp’ the flavour compounds. Only activated carbon removed any guaiacol.  

A sample of cabernet sauvignon grapes had been exposed to fire smoke for up to eight hours, 3-4 weeks before veraison. The concentration of guaiacol and 4-methyguaiacol fell only marginally in the subsequent to harvest, possibly as a result of dilution with berry growth. 

The AWRI report said: “The results of these investigations provide conclusive evidence that tainting of grapes and wine by bushfire smoke can occur, and potentially have a major economic impact. Many affected white juices, wines and especially sparkling base wines, were deemed to be ‘unfit for purpose’ and were consequently severely downgraded in terms of value.”

Western Australia

In Western Australia, prescribed burns are an important part of landscape management. Drew Haswell, policy and science advisor at Western Australia’s (WA) department of environment and conservation said they carry out “prescribed burning in forests to stop the impact of damaging wild fires. We can only burn wet Karri forests in a small window of opportunity in April/May [when they are at their driest].” The Pemberton wine region is nearby these burns.  

The department of environment and conservation has recently been working with the university and the wine industry association (WIAWA) to minimise the impact on the wine industry. In 2007, said Sue Vidovich, chief executive officer of WIAWA, they have “formed a Smoke Taint Working Group comprising representatives from WIAWA, the Department of Agriculture and Food and the Department of Environment and Conservation to learn more about the effect of smoke on vines and the resultant wines. We have one research project currently underway”.

Kristen Kennison, viticulture research and development officer at the Department of Agriculture and Food, Western Australia had been carrying out research for the previous 18 months. She said: “We need to know more about how smoke ends up in grapes, and what part of the grape smoke ends up in. Over 4000 compounds have been detected in smoke alone. A whole range of compounds could contribute to taint. Research is looking at the compounds within smoke taint. We’re using guaiacol and 4-methylguaiacol as indicators. We’re looking at particular growth stages of the vine, when during the season is smoke a particular problem. Also the timing and duration of smoke events. How vines assimilate and translocate the smoke compounds. We’ve applied smoke to vines for different durations, and we’re currently making wine from that fruit. Once we have knowledge, then can work on amelioration.”

Victoria

In Victoria in 2007, over 1m hectares were affected by bushfire, with King Valley and Alpine Valleys the worst affected. Having already lost a big chunk of the crop to frost and drought that year, extensive bush fires left smoke palls over vineyards.  It was estimated the combined effect of the vintage’s natural conditions may cost the region AUD$70m. 

Joanne Butterworth-Gray, chief executive, Victorian Wine Industry Association said: “We had six weeks of bush fires, starting on December 3^rd, finishing in the third week of January ’07. About 50% of the state was covered in smoke haze for this time. Some companies in the north east are not using those grapes for their own brands. Some is left on the vines, some is blended out. What you can’t afford to have happen is the strength of ultra premium brands being affected”. Some producers have treated their wines with carbon.

Butterworth-Gray added: the Victorian government put forward a lot of funding for sustained research into the long term effects of smoke taint, and to assist businesses in getting over those effects. We don’t know if there is an accumulation effect in the vine itself, so part of the research will look at this.” 

In 2009, there were again catastrophic bushfires in Victoria – the Yarra Valley – some started deliberately, which this time killed nearly 200 people.  Tony Jordan, who heads up the Yarra Valley Winegrowers’ Association said after years of below average rainfall, and after “a four-day heatwave in south east Australia [at the end of January] flammable eucalypt forests were tinder dry. Strong, hot, northerly winds, with gusts over 100 kilometres per house created a recipe for bushfire disaster.”

About a quarter of the Yarra Valley vineyard was directly affected by grass and bush fires.  Jordan added: “Many vines will be pruned back severely and they’ll recover. Vines were already shooting green growth, 8-10 weeks after the fires.”

It is now known that the effect in a single season is cumulative. Jordan said their “experience of smoke in 2007 and 2009 indicates that exposure to several days of moderate smoke levels is required to produce an effect above threshold.” The intensity and duration of exposure are also implicated, with even short periods resulting in a small amount of smoke compound pick up, though often below organoleptic thresholds.

Aftermath of bushfires, Cederberg, South Africa, 2009

Treatment

A sporadic and individual problem it may be, but the commercial decisions can be harsh, especially without contaminant insurance. Some sort of treatment exists (see Memstar below). David Wollan, director of Wine Network said: “A number of wine producers have said they’re not prepared to take the risk and they rejected a lot of grapes.” But others, especially a larger producer who has more than one tier of brands, an option is to treat the wine and put it into a lower tier of wine brand.

Detection thresholds vary by style of wine, with fruit for sparkling base wine having the lowest threshold. One industry insider said: “a smoky, bacon flavour in a sparkling base might see a significant downgrade for example from AUD$3/litre to AUD$0.30/litre.” The threshold for reds is obviously more forgiving, but varies by grape variety. Blending away is one option, for larger wineries, but a guaiacol concentration above a certain level is likely to see the fruit left on the vine without commercial value. It’s clear that smoke taint is unpleasant. But the overall impact to the industry is not great.

Memstar – a treatment option (MEMbrane Separation, Treatment And Recombination)

This a group of reverse osmosis membrane processes. Wine is pumped under high pressure. Compounds of low molecular weight pass through a highly selective membrane. The liquid passing through the membrane is treated to remove some of the unwanted compounds, and the treated portion is returned – ‘recombined’ to the wine.

For smoke taint a ‘loose’ membrane is required. Guaiacol and 4-methylguaiacol have a higher molecular weight than, for example, ethanol and acetic acid.  Compounds are removed by passing the liquid through activated carbon filters, though this also removes some other wine components that passed through the filter with guaiacol.  The  treated portion is added back to the wine.

Depending on the level of taint, it costs about USD$0.30/litre to use the technology.

David Wollan, director of Wine Network, which runs the Memstar technology, said: “We can reduce the taint components. We can’t eliminate the smoke taint, but we can take out a portion of what’s there each time the wine passes. We estimate 8-10% of taint is removed each time.  Wine is processed until it’s at an acceptable level, which could be 3 to 10 times going round the loop.”

Smoke taint – not brettanomyces.

Smoke taint is not to be confused with brettanomyces, which is a taint cause by yeast. Wines made from smoke tainted fruit show an acrid, burnt, ‘morning after’ ashtray note.  Wines tainted by brettanomyces display horsey, medicinal, farmyard, ‘elastoplast’ notes.

The compounds responsible for these two taints are different, but they do all come from a group of volatile phenols

• Smoke taint culprits are guaiacol and 4-methylguaiacol.
• Brettanomyces culprits are  4-ethylphenol and 4-ethylguaiacol. 

With brettanomyces, many argue a little influence offers complexity to wine. With smoke, any detectable amount will be regarded as a fault in an aromatic white wine, but in a robust wine aged in new oak, the story is more complicated. A proportion of the two main compounds measured to identify taint, are often regarded as positive complexing influences, so the line between flavour enhancement and flavour fault in robust reds, as with brettanomyces, is a fine one. More research needs to be done on the other compounds that contribute to smoke taint.

Australia has been long derided on the international stage for the poor quality and varietal typicity of its pinot noir wines, and little wonder when Australian imagery has been vast, spectacular, beautiful, panoramic scenery, all of which is the antithesis of the capricious, site-specific, agoraphobic pinot noir. But the last decade has seen a step change in focus as passionate winemakers have been pandering to the variety’s prima donna needs, with some particularly sweet success.

East Coast Tasmania

It’s arguably not even as niche a product as pinot noir is in France. Perhaps it’s one of those weird statistical comparisons, but Australia, with 2.5% of its vineyard area dedicated to pinot noir, has nearly twice the proportion of pinot noir than Burgundy, which has a meagre 1.3% of France’s vineyard area. For the purists, the absolute hectarage is 4,400 hectares (ha) in Australia versus 10,700 ha in Burgundy.

A quick scan of auction house Langton’s latest classication reveals eight pinot noirs, up from two in the first edition. Langtons’ Andrew Caillard MW, said there had been “a genuine improvement of absolute quality over the last ten years … the top regions are really the Melbourne Dress Circle (e.g. Geelong, Macedon, Yarra Valley, Mornington Peninsula) and Tasmania.”  

Pinot noir plantings may be up only 6% since 2001, but it was also around this time that serious pinot noir producers were getting serious.  Noel Young, proprietor of Noel Young Wines, International Wine Challenge (IWC) Australia Specialist merchant of the year in 2008, which lists 23 Aussie pinot noirs said “progress has been rapid in the last four or five years with the right clones in the right locations, but it’s been happening in Tasmania and Mornington Peninsula since the mid-to-late 1990s as growers have done vintages in France” and experimented with different clones in different soils.

Cool Climate Chic

There’s no getting away from the fact that pinot noir performs to its most precise and perfumed best in cooler climates, and this factor oversees the recent themes of new clonal material, vines coming of age at about a decade old, the trend to site-specific and single vineyard plots, as well as the growing band of producers rocking and rolling with the pinot noir drum.  See table at the end for key areas.

Tasmania certainly has the edge here. “The major natural advantage for Tassie is the wonderful cool climate” said Claudio Radenti of Freycinet Vineyard, “Around the world all the great pinot noirs hail from cool climates. Pinot noirs from warmer climates can be a little heavy and jammy lacking finesse and the gorgeous velvety pinot noir texture.

“The quality potential in Tassie is enormous and exciting. Longer slower ripening conditions favours retention of delicate fruit aromas and flavours” and coolness of climate enables some of those classic, ethereal attributes to thrive.  According to the chief winemaker of Kreglinger Wine Estates (Pipers Brook, Ninth Island and Kreglinger sparkling) René Bezemer, “we retain more of our fruit-derivative components. I look for floral attributes, delicate perfume and distinctive fruit aromas – violets, darker berry fruit, dark cherry.  If I see blackcurrant it’s shrivelled fruit from too much sun. If see strawberry, it’s been picked too early.”    

Pinot Noir

Exploiting the trend to cool climate chic, Tasmania’s vineyard area has nearly trebled since the turn of the millennium, with in 2008, 45% of the yield coming from pinot noir.  In 2000, it accounted for less than one-third.   

Over on the ‘big island’, Mornington Peninsula is oft-cited as producing some really good pinot noir. And internally, Mornington Peninsula winemakers have been talking about sub-regions for some time already: three of them.  Pinot noirs from the north are bigger, more muscular, darker style.  The hill – Main Ridge – show delicate perfumes, floral, elegant notes. 

Ten Minutes by Tractor is one Mornington Peninsula producer doing very well, especially with their single vineyard wines, which can all be reached in ten minutes when travelling by tractor. Neil McAndrew, managing director of their UK importer H&H Bancroft, said: “For us Ten Minutes by Tractor have been the best pinot noirs we’ve ever found in Australia.  They are the bridge between Burgundy and Australia. They have some classic pinot noir characters, but they’re not trying to be Burgundy; they have a savoury character which I haven’t seen in the past from Australia. “The volumes are also Burgundian, and what Bancroft get flies out of the door, according to McAndrew, who also said Ten Minutes By Tractor is the sort of premium Australian wines the restaurant sector is looking for.  It sells in places such as The Square, Home House, Fortnum and Chez Bruce.

Kooyong is another highly respected producer in the Mornington Peninsula, planted as recently as 1996.. The managing director of their UK agent, Great Western Wines, said: “He’s producing great quality in terms of acceptance in the market.  The wines that really tell the story of Kooyong are the wines made from individual parcels, retailing at £25 to £30. But Kooyong also makes two other levels retailing at £15-£16 and about £11, and the acceptance for these has been very good, and remains so, with good success in the independent sector and in the on trade.”  The commercial groundswell is certainly beginning in the UK.

Climbing, Climbing

Both Mornington Peninsula, and Geelong, noted for the likes of Bannockburn and By Farr – on the other side of Port Philip are low-lying coastal zones which garner cooling winds from the Bass Strait. Yet planting at cooler, higher altitudes is also beginning to reap rewards in places such as the Adelaide Hills, though the Macedon Ranges are arguably more successful.  It was in the Macedon Ranges, at 560m elevation, that Phillip Moraghan of Curly Flat settled, having eliminated both Geelong and Mornington Peninsula.  He explained his search was “all about pinot ‘grief’, looking for soil, cool climate, water” all issues for this fastidious grape variety.

But is arguably Bindi, 500m up at the southern end of Macedon that leads the field. The vines, which require straw buttressing in winter, have some age, having been planted in 1988, with 1991 the first vintage.  Owner Michael Dhillon said: “We see about 7-9 years as a real turning point for complexity and structure.”  

Yarra Valley

Steve Webber, winemaker at De Bortoli in the Yarra Valley, also cites vine age, as well as continuously improving quality practices, saying : “I think that with more care and attention to the manual practices [hand picking, hand sorting, whole berry fermenting], we have seen a huge shift in our own quality … I think pinot noir is a vine age thing. Generally our quality is improving with vine age. But poor quality old vine material is not good. I am just starting to make a single vineyard wine from a property that has pinot noir planted in 1990 and 1997″, adding that single vineyard is an important way forward for pinot noir.

A criticism of the Yarra Valley, making as it does, everything from sparkling to fortified, is that its pinot noirs don’t do so well in the warmer years, or indeed the warmer areas, so you need to be in the higher altitude, more southerly, reaches of the valley. But not everyone thinks like that. Rob Hall, winemaker at Mount Mary, just about 30m above the valley floor said: “you can still make very good pinot noir in warmer years, but may not be in the style you’d choose.  Normally we’d like a more delicate style of pinot noir, we’re not keen on tannin or wood. So you might get more tannin in a warmer year. But you can do something with the canopy to keep the fruit cooler.” He added “we’re purchasing south facing slopes for pinot noir and chardonnay to counter some of the warmer years. ”

Champion Clones

Along with site and vine age, newer, trendier clones such as 667, 777, 114 and 115 have been in Australia, also for about a decade. Pirie said there had been a “big impact of new clones and new sites leading to more refined pinot noir expression. At Tamar Ridge, up to 2006, wines were dominated by ‘old’ clones, plus MV6, an old introduction into Australia. These are robust clones but are lacking some of the high notes of true Burgundy.  In the last few years the Pommard clone and the ‘Bernard’ clones from Morey St Denis were introduced. A blend of Pommard and MV6 will be one of the Tamar Ridge reserve wines in 2008.  The Dijon clones, grown on the right soils, have the classic perfume of cherries and summer pudding berries.”

Creature Champions

But above all, human champions are at the vanguard of Aussie pinot noir’s lifting reputation.  Dhillon said: “15 years ago it was young vines, often in poor locations, little experience in the vineyard and winery.  Most [winemakers] did not have a philosophy based on understanding the international benchmarks.  Today, the vines are older, vine management better, yields lower, winemaking more appropriate and the best sites are proving themselves capable of expressing unique qualities.”

“We have inspired growers and winemakers who have a passion and a thorough understanding of benchmarking, using the correct clones and the right sites to grow this unique and challenging grape variety” said Dalwhinnie Wines’ winemaker David Jones, adding “the Mornington Penisnsula Pinot Noir Celebration [a bi-annual pinot noir fest with international flavour, which started in 2003] has been an iconic event and a great inspiration to reach even higher quality levels.”

Another such event is the Victorian Pinot noir workshop, a winemaker-only event, now in its 6th year, where more than 60 winemakers come together to discuss the grape and how to get better and more from it.  Having witnessed “a growing ‘collegiality’ amongst Victorian winemakers who venture down the love-struck path of growing and making pinot noir, more so in this state than I have observed elsewhere” the Victorian Wine Industry Association’s chief executive Joanne Butterworth-Gray thinks this co-operation has been “critical to the success of Victorian pinot noir on the world stage.”

The scale may necessarily be small for the best results, as indeed it is in Burgundy, and as Radenti said, “there are considerably more serious producers of pinot noir in the current decade than in the previous one. There is better understanding by these young professionals of what it takes viticulturally and in the winery to come up with the goods.”

Pinot noir plantings in Australia

A lot of areas are experimenting but a few core regions dominate higher quality production

Adelaide Hills                       391 ha

Geelong                                   170

Macedon Ranges                    58

Mornington Peninsula       252

Tasmania                                 625

Yarra Valley                          706

Sub total                              2,202   50% of total pinot noir plantings