A new study held by researchers at Columbia University and Harvard University has proven that human-caused climate change is resulting in early grape harvesting. The change has happened periodically but now, it is changing the quality of the wine.
A wine bottle is the result of a complicated process in which the environment plays a key role. European vintners use the word “terroir” to define the process of grape growing and wine making, grapes and terroir are sensitive processes that change with environmental factors.
The study published in the Nature Climate Change journal investigates the periodic change experienced in french vineyards. Since terroir is a sensitive process, any rain or temperature pattern change causes grapes to grow slow or not growing enough.
Weather change affects the wine process, producing sugar levels that don’t allow enough alcohol content. At the same time weather can also help grapes to grow faster improving the sugar content in the fruit, increasing alcohol levels and reducing acidity.
The researchers analyzed data from the last 400 years, especially wine harvest data from France since it has major wine growing regions such as Bordeaux and Burgundy. To understand better the change, the scientists analyzed independent sources of climate information, trade archives, church documents, local weather observations between others.
The study found that grape harvest in France has happened earlier in the last 30 years, according to the research it has happened two weeks earlier compared to the last 400 years. This process has occurred naturally, normally an early grape harvest is associated with higher wine quality.
“So what we were able to do is look at climate and wine over a much longer time period than people have typically done and see how exceptional the most recent decades are compared to the last 400 years of climate and wine variability” Said lead author Dr. Benjamin Cook from the Columbia University’s Lamont- Doherty Earth Observatory
While studying climate changes and wine quality both researchers found that in the year of 2003 the most dramatic case of early grape harvest happened. The early harvest was due to the massive European heat wave that took the lives of 15,000 people across the continent. The harvest happened over a month earlier, most people were expecting great wine quality for that year, but according to the study, there was nothing particular about that year’s harvest.
Further research that included the statements of an experienced vintner in California, that assured early harvest only helps white grapes, since they don’t need any flavor or color development. But in the case of red wine, there’s a series of developments that must be concluded in the grape before the harvest.
Elizabeth Wolkovich, a biologist from Harvard University and co-author of the study assures that global warming will reach a tipping point and the study has concluded that in the future higher temperatures will not result in higher wine quality.
In the past few years, Europe has suffered from lower wine volume, lower wine stocks and higher prices thanks to the disastrous climatic conditions that affect the grape harvest limitation according to Euromonitor in 2015.
Climate change may affect wine flavors in factors that don’t include the grapes or the vineyards. Cork trees, the branch in which the grape is born, have been changing in the last two decades, cork bark has become thinner regulating less oxygen intake and lowering the evolution of wine over time.