How does climate change affect wine?

More alcohol, different taste, different color, different aroma… The climate changes This has caused a change in the organoleptic profiles of wine and challenges producers to apply different techniques to keep the characteristics of their production intact.

The main reason for this is the greater number of days with high temperatures and heat waves that recur every year, which directly affect the concentration of sugar in grapes and, consequently, the higher percentage of alcohol in wines, explain the voices of Efe experts from the sector.

“Alcoholism is important relevant in what is a sensory profile. The higher the alcohol level, the fruity notes, which are highly valued, are reduced,” says María Pilar Sáenz Navajas, oenologist and chemist at the High Center for Scientific Research of Spain (CSIC).

The expert, who also works at the Institute of Viticulture and Winery (ICVV), adds that a higher alcohol level means that the wine is more aggressive in the mouth and that green characters appear on the nose.

Technically, this higher alcohol level is due to a “separation between the technological and phenolic ripening of the grapes” caused by the high temperatures, explains R&D&i technician and Wine Technology Platform (PTV) project director Andrea Casquete.

Grapes reach a high level of sugar (technological maturity) that eventually turns into alcohol, while phenolic and aromatic maturity (which indicates the optimal state of compounds such as tannins) has not yet been reached, says Casquete, an expert in viticulture and its adaptation to climate change.

“The problem of phenolic ripening It brings us a little head, because it is the cornerstone of great wine. The lack of maturation causes much more difficulty in obtaining a balanced wine without bitterness, vegetables…,” admits Rioja Qualified Denomination of Origin (DOCa) Technical Director Pablo Franco.

Furthermore, the fact that in the hot months the thermal variation between day and night is less and less, significantly affects the formation of anthocyanins, “phenolic compounds that are involved in the color of the wine present in the skin of the grapes”, says Casquete.

This expert also reports that the higher frequency of solar radiation on the soil reduces the acidity of the wine, causing a strong organoleptic imbalance, “not only in white wines (in which freshness resulting from acidity is always sought. ), but also in red wines to maintain color and potential aging over time.

Wines in mutation
These changes in sensory profiles can cause a wine that normally has certain characteristics to taste different, change color or give off other aromas.

For now, the variations are not drastic and “the typical profiles of each designation of origin or variety can be maintained,” says Sáenz.

“With the help of technology”, yes, the CSIC expert points out, which illustrates how the sector works to reduce the degree of alcohol that results in its preparations.

He states that viticulture is looking for new varieties of vines, better adapted to climate changes and capable of maintaining sensory typicality in the final wines, while wineries implement technologies that allow reducing the amount of alcohol in already produced wine.

Franco, for his part, points out that currently the “quality” of the wine is not threatened, but that “small variations in smell or taste” may appear, which in the case of DOCa Rioja wines he considers to be “minimal”.

“The challenge is to try to influence i to change the characteristics of our wines as little as possible and it is crucial to apply targeted viticultural techniques carry out each vegetative cycle with the aim of achieving ripening that preserves the typicality of the territory,” concludes the DOCa Rioja representative.