Climate change and wine quality
Sometimes I hear around that higher alcohol level means a high quality wine. I really don’t know where, who and when this came from. So far, after some experience tasting wines I have never seen any correlation between quality and alcohol level. So let’s try to discuss it.
Before trying to understand the consequences of global warming and climate change on wine, we must first understand and define what factors influence the quality of wine. While grape quality and climate play a significant role, post-harvest winemaking techniques such as maceration, fermentation, extraction, and aging also influence wine flavors immensely. But here lets focus on grape quality.
With the gradual increase in temperature and changes in the periods of rain and drought, we have also seen a significant change in the grape ripening time and consequently in the harvest period. As the ripening time decreases, we can also observe a change in the organoleptic composition of the must, which may affect the expected characteristics of certain terroirs.
Another considerable factor is the increase in sugar concentration in the grape and the decrease in acidity. Increasing sugar concentration causes an increase in alcoholic gradation at the end of fermentation. Often alcohol volume reduction techniques need to be used to maintain the characteristics and style of a particular type of wine.
So when we get into a quality discussion we need to understand that some factors resulting from global warming can cause a very significant change in the taste, aroma and texture characteristics of wine. In order to build an assessment that gives a sense of the changes that are taking place, it is very important to perform vertical tastings or even to take notes of your tastings over the vintages for a comparative study.
As a direct result of climate change we are already seeing drastic changes in some producing regions. Can you imagine a Portuguese grape variety as part of the Bordeaux blend? The wine world is changing very fast.