First published in 2015 by The Drinks Business.
Whilst certain climatic parameters are known to vary with increasing altitude above sea level (asl), it appears that high altitude viticulture is nothing without its anagram, latitude. “Altitude has a meaning when related to the particular conditions of a given vineyard” said Fernando Buscema director of the Catena Institute in Argentina. John Worontschak, who consults for Mexico’s Casa Madera said “high altitude matters only where it is hot below. In the UK, for example, 100m is high altitude because of its high latitude.” Buscema added “I would define high altitude as the minimum altitude at which the environment significantly affects grape and wine quality. The exact number might vary with the latitude, geography and proximity to oceans.” Laura Catena, the managing director of Bodega Catena Zapata founded the Catena Institute in 1995 to, among other things, “try to figure out the magic of high altitude”.
Nonetheless, attempts have been made to narrow a definition. In Europe, CERVIM (Centre for research, environmental sustainability and advancement of mountain viticulture) was set up to defend the wonderfully termed ‘heroic viticulture”, which exists only above 500m asl (plus on minimum 30% slopes and terraced/embanked vineyards). Around 5% of Europe’s vineyards qualify, with more than half in Switzerland and Portugal.
Elsewhere, some in Argentina suggest 1,200m is a decent starting point to qualify for high altitude status. Included would be Mendoza’s Valle de Uco (1,200m), Famatina in La Rioja (1,400m) and the Calchaqui valleys (mostly 1,700 to 2,200m). But Ignacio Lopez, winemaker for Pernod Ricard Argentina remains ambivalent, saying “altitude is not the same at 1,200m asl in Mendoza as in Salta. It is not the same at 2,000m asl in a 33° latitude as at 2,000m asl in a 26° latitude.” The frost-free season is too short at the higher latitude, but maybe okay at the lower latitude. Lopez added further complexities exist: “the soil is not the same, the sun exposure, the wind, the humidity are not the same.”
In Mendoza alone, Buscema said “we have clearly seen positive changes in grape and wine quality at altitudes over 1,000 meters above sea level and more dramatically around 1,500m asl.” And, he added “some of the most attractive [malbec] wines comes from our Adrianna vineyard [Gualtallary, in Tupungato], located at almost 1,500m”. Studies at the institute showed “malbec at high altitude usually has more intense colour, a denser palate and a longer aging potential than its counterpart from low altitude. Also, it shows lower levels of alcohol and higher acidity, resulting in a more harmonious age worthy wine.”
So no easy linear equation for a definition of high altitude viticulture.
Or is there? Professor Hans Schulz, president of Hochschule Geisenheim University, appears to link altitude and latitude in a single seamless manoeuvre, saying “sea level is the reference for altitude, but it should be the baseline temperature at sea level” for grape growing. He explained “between April and October [northern hemisphere] you need a baseline temperature, average minimum 12°C”, like a little bit south of London, he added. “In Germany, at 15°C, you can lose 0.8°C per 100m, so 400m above sea level would be 11.8°C. Therefore 400m asl is close to the limit for an area such as Rheingau. In northern Italy, where the April to October average temperature is 17-18°C, you can grow grapes at 600-800m altitude.”
High altitude asl for any given region becomes the limit of being able to grow and ripen grapes; any higher and the average growing season temperature becomes so low that cultivation is not possible. If the baseline growing season temperature at sea level increases to 22 to 24°C at the Tropics, you can increase altitude a lot before you hit the threshold. This rough guide, he emphasised, takes no account of other factors such as exposition, or UV.
Other climatic and geomorphological factors inevitably play their part. For example temperatures in Europe’s highest vineyards – the Canary Islands “should be hotter than they are” said Pablo López Betancor, the winemaker at Bodega Frontos, because of their relatively low latitude. “However, the trade winds prevent temperatures in the archipelago from being higher, and they bring with them considerable benefits in terms of humidity and uniform temperatures across the year.” He added “the trade winds affect the Islands almost every year, by virtue of the latitude at which the Islands lie and their proximity to the anticyclone that occurs in the Azores.” This combined with the high altitude allows successful viticulture.
Diurnal temperature variation can help too. Katogi Averoff winery has the highest vineyards in Greece, around Metsovo. Alexandros Ioannou explained “Metsovo is among the coldest places in Greece and the diurnal temperature variation is 15°C.” He added “Metsovo is also amongst the places with the highest rainfalls per year in Greece (1600mm)” but the weathered schists and gravel, plus the gradient allow excess to drain. Other mesoscale factors come into play: “we have noticed that the same grape variety, for example cabernet sauvignon, matures differently according to the altitude [between 950m and 1050m] of each parcel, the orientation and the ventilation” and in one or two years a decade it struggles to ripen.
Back in Argentina, Martín Coscia, general sales manager at Bodegas Colomé said they have around “20°C difference between day and night”, which keeps freshness and avoids over-ripeness. He added “In all the high altitude vineyards we feel the more delicate aromas have a better expression: mostly the floral, but also the mineral and the fresh fruit.”
It’s not all plain sailing, there are risks of growing grapes at higher altitudes asl. In Colorado, USA, where the new era of winemaking is the same age as that of Marlborough, NZ, almost every vineyard is above 1,200m asl. All the key classic cultivars were planted, but Colorado State University viticulturalist Dr. Horst Caspari said “cabernet franc has been really successful. It breaks bud early, so it’s prone to spring frost, but it has mid-winter hardiness. It’s the only grape variety that’s consistently produced better than average in the last 15 years. It’s almost never the best-producing variety, but equally has never failed.”
Then, heat spikes can accelerate the growth cycle. Caspari said “at 1,500m we can hit 40°C in July, getting a lot of heat in a few days. Once in the ripening phase, we can still get high 20°Cs-30°C, so can accumulate sugar pretty quickly.” But by the time you reach 1,800m to 2,000m, he added “it would be nice to have warmer temperatures at the end of the season.” They would agree in Italy’s Val d’Aosta, where the aim is to harvest before the first snows.
LVMH started at the other end – their quest was for a location suitable for red Bordeaux cultivars. China provided said location, and vineyards are planted at 2,100m, 2,300m, 2,500m and 2,600m asl. Jean-Guillaume Prats, the president and CEO of the Moet Hennessy wine division said “Yunnan is similar to Bordeaux, with a high mountain identity: same maximum temperature, lower night temperature, stronger UV, drier end season” with the location protected from otherwise heavy rains. Hmm doesn’t sound so much like Bordeaux …
So, it seems high altitude asl is only a thing relative to latitude and other natural features, including choice of cultivar … “if you’re getting close to 12°C, you couldn’t cultivate cabernet sauvignon, but you could cultivate Muller-Thurgau, for example” said Schulz.
- Temperature decreases by about 0.6°C to 0.8°C (depending on latitude) per 100m increase in altitude above sea level (asl)
- Diurnal temperature range increases with higher altitude asl. Lower night time temperature reduces respiration rate, particularly of malic acid, of grapes.
- Ultraviolet radiation increases with increasing altitude asl. Increased photosynthesis: thicker skins, more anthocyanins and polymerised tannins.
- Growing seasons shorten between 2 and 4 days per ~100m increase in altitude asl. Vine growth can still be strong because of greater UV and higher diurnal temperature range
- Carbon dioxide uptake is lower at higher altitude asl, which limits photosynthesis. Vine growth may be stunted.
- Risks such as frost, hail, winter hardiness, winds and higher production costs increase with higher altitude asl.
Are these the top dozen countries with the highest altitude vineyards?
|Country||Region||Producer||Altitudemetres above sea level (asl)|
|1||Argentina||Upper Calchaqui Valley, Salta||Colomé||3,100|
|3||China||Yunnan||LVMH||2,300 – 2,600|
|4||USA||Colorado,West Elks AVA||Terror Creek Winery||1,950|
|6||Spain||Tenerife, DO Abona||Bodega Frontos||1,650|
|7||Mexico||Casa Madero||1,500 – 1,700|
|8||Brazil||Santa Catarina||Vinícola Hiragami||1,427|
|9||Australia||New England, NSW||Flower’s Black Mountain||1,300|
|11||Cyprus||Kyperounda||1,100 – 1,400|
|12||Greece||Metsovo||Katogi Averoff||1,000 – 1,300|
Sources: compiled by the author with unreserved and grateful thanks to folk at many generic and promotional bodies, including of countries not making the cut.
NB: excludes Aurelio Montes’ experimental <1ha recently planted in Peru at 3,000m
NB: Just missing the cut: South Africa and Switzerland, both with vineyards at 1,150m.
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