Wines are getting higher

Assumpta Mateos Fernández / Míriam Lampreave Figueras
Researchers at the Department of Biochemistry and Biotechnology
mariaassumpta.mateos(ELIMINAR)@urv.cat / miriam.lampreave(ELIMINAR)@urv.cat

The vine is a hardy crop, well-suited to the arid and hot Mediterranean environment. A sign of its resilience is that it is grown in areas affected by the changes in climate of recent years, namely higher temperatures with sudden heatwaves during ripening and irregular, often torrential, rainfall.

One of the most important effects that climate change can have on the vines, on the grapes and, therefore, on the final product, wine, is an increase in alcohol content and a decrease in acidity.

High temperatures also lead to a loss of aromas and uneven ripening. Likewise, a lack of water causes reduced yields, stunted growth, premature defoliation and, in extreme cases, even the death of the vine. It is estimated that by the mid-21st century, climate change will mean that there will be 17% less water availability in areas with a Mediterranean climate, which is where the majority of vineyards are located, for example Catalonia, southern France, California, Chile, etc.

The shortening of the phenological stages caused by high temperatures leads to an earlier harvest; in many areas the harvest takes place about fifteen days earlier than it did fifty years ago, meaning that early varieties are now harvested towards the beginning of August. The earlier harvest causes a mismatch between technological and phenological maturity: the flesh of the grapes develops higher sugar levels while parts such as the skins and seeds still impart astringency, lack of colour and unwanted notes to the wines.

In some cases, climate change brings extreme episodes of storms and hailstorms during the ripening season, which can also damage crops.  

Another significant effect of climate change is the increase in pests and diseases affecting vineyards. These are becoming increasingly common and severe, as was the case in 2020 with downy mildew, which caused the loss of the entire harvest in the worst-affected areas.

The increase in temperatures due to climate change has affected the suitability of different varieties, such that in some wine-growing areas, previously well-adapted non-native varieties are beginning to experience problems. This in turn means that new regions will have to be sought for planting the vineyards, for example, higher latitudes, greater altitudes or north-facing slopes.

It may also be necessary to revive local varieties that had been abandoned due to their low yields or non-standard organoleptic characteristics, which we now know are better adapted to their traditional wine-growing areas from which they originate.

As a result, wine producers are seeking higher-altitude areas in order to escape the heat: 'The rise in temperatures has meant that vine cultivation has had to move to previously unimaginable areas, such as Cerdanya or Tremp’.