Climate change and natural wines

Last summer, I was in Bordeaux, exactly in the Côtes de Bourg vineyard. I remember the intense heat and the blazing sun, not the typical summer weather I use to enjoy in the past. While it’s important not to conflate isolated extreme weather events with broader climate patterns., but there is one reality climate change is real, and it will have consequences in the wine world. Let’s take a look at some of them and also at how winegrowers and winemaker can adapt their practices to the changing climate.

After all, on the surface, rising temperatures might seem advantageous for winemaking. More heat should give a little fruitier flavor. The effect of climate change is not limited to the increase of heat on summer days, it is a huge difference in average temperature during the year and this will affect the life cycle of vines. The first consequence, summer heat waves, which will be more frequent, mays have an impact on some grape varieties. Take the Merlot variety for example, it does not support well these heat waves as it can mature too soon. This will have an impact on the wine quality.

However, there’s another dimension to consider.; the average temperature rise means that the flowering of the vines arrives earlier in the year, with a non-negligible risk of frost sometime later. Harvest will occur earlier; it is not rare to see harvest in August while 10 or 15 years before September and October.

But to have a quality wine, the maturation of the pulp must coincide with the maturation of the skin. The skin maturation process requires a fresh night or at least a large gradient of temperature between the day and the night. This occurs generally during September. But at this time the fruit may be full of sugars and may lose a large amount of acidity. The result will be very high in alcoholic wine with little or no acidity. Wine is an acidic solution, acid is an essential element of the wine, it gives it structure and it is a natural preservative. Losing the late maturation of the vines will have a very negative impact on wine quality with wine very Hight in alcohol and low in structure, the fruity flavors will also be impacted and more spicy flavor can appear.

Change in wine climates

Climate change will also bring about shifts in the characteristic climates of established wine regions.. Bordeaux may become as hot as Seville, The Beaujolais, but also the Loire and the Bourgogne may have a climate similar to the Rhône Valley.

Moreover, less renowned European regions could emerge as ideal for viticulture.. Thinks about the region of south London, the soil is similar to the Parisian soil, which makes it ideal to produce Champagne-style wine. Other regions like Denmark or Sweden could also become the new Jura or Alsace

In the Beaujolais vineyard, climate change and rising temperature may have some positive effects. The higher level of sugar and alcohol may give the wine more quality.

Rising temperature is also a problem during the winemaking process. As the harvest starts more and more early, the winemaking step starts early too, vatting the grapes and starting the fermentation require temperatures around 15°C for white wine at the start (during the skin contact), and the fermentation process is exogen, the temperature of the grind can increase up to 30°c. But what if the temperature of the cellar is higher; poor fermentation.

Indigenous Yeast in Natural wines

And there is a higher issue, especially for natural wine. Natural wine uses indigenous yeast for alcoholic fermentation. But with climate change, vineyards will experience droughts and heat waves just before harvesting. It will prevent or limit the development of microbial flora. The level of indigenous will be too low to start a normal fermentation. It could be a big problem for the coldest vineyards like Jura, Alsace, and others that do not experience warm summers. In the coming years, natural wine profiles may change drastically.

Are winegrowers and winemakers helpless?

There are many things winegrowers can do, starting with techniques used in organic and natural wine vineyards. Having living soil, which implies a huge reduction in herbicides and pesticides, keeps the soil its biodiversity. Also improving the canopy, and adding trees in the vineyards may help to create local microclimates. Another technique, used in Beaujolais, increasing the height of the trunk, from 50-60 cm to 90 cm. This limits photosynthesis and therefore lengthens the maturation period.

Late maturation is the key to adapting vineyards to climate change. If the maturation occurs later and coincides with the skin maturation consequences for wine-making, only, will be limited.

One possibility is to grow vines at higher altitudes. On average, temperatures are lowered by 1°C every 100 m in altitude. This is the choice made in Spain, going up in the Pyrenees, in places where no vines have ever grown.

But having higher mountains will not be a solution for all wine regions in Europe, Except for the Alps and the Pyrenees, higher altitude is almost impossible.

New grappes varieties

To delay the maturation, some regions planted new vines. In the Beaujolais region, some Gamay varieties that were left over because of their late maturity are replanted in the hope they will better support the raising temperature. More radical, in the same region, where Gamay and Chardonnay exist for centuries, varieties from the south of the Rhône valley are also planted, Syrah for red wine, and Viognier for white wine. These varieties are more adapted to heat waves and are supposed to have a late maturation compared to Gamay.

A more radical approach has been adopted in the Bordeaux, region. As the vineyard will soon have a climate more or less like what we have around Seville in the south of Spain and the traditional varieties like Merlot. Since 2009, scientists are testing 52 varieties coming from the south of France and other parts of southern Europe. One of the selected varieties is the Touriga Nacional, a variety from the Douro Valley in Portugal. After all, Bordeaux and the Douro Valley share the same ocean frontage with the Atlantic.

Another solution experimented in the Champagne region is to use multi-hybrid (several crossing between different Vitis families) vines. The Voltis, authorized in 2023, this new variety has the ability better manage its water needs by digging its roots deeper.

We know that climate change is a reality. It will have an impact on our future life. Wine will be impacted too, but adaptation is one way. But the taste will certainly be impacted. At the same time, new wine regions will emerge and may gain popularity. Times are changing and the wine we drink today may not be the same in 20 years.