ROME, Italy ― The family of Alberto Marsetti has made wine in Valtellina, in the north of Italy, for at least six generations. So he noticed when things started to change.
“The watershed year was 2007,” Marsetti said. “That’s when we realized we had to stop thinking in terms of exceptional years and that it was ‘normal years’ that had changed.”
In the last two decades, Marsetti said, he had to adjust his winemaking to account for climatic abnormalities he attributes to global warning. Rather than a rise in average temperatures, earlier springs and warmer autumns made his grapes sweeter, leading to more alcoholic wines.
The phenomenon has been especially conspicuous in the hillsides around the village of Chiuro, where vineyards rise as high as 2,000 feet above sea level.
“Twenty years ago,” Marsetti said, “we struggled to get decent grapes from the vineyards at such an altitude. We used the grapes to make down-to-earth table wines, those you can have a couple of glasses of at lunch every day, not for the top quality wines.”
“Now, instead, we get medium- or high-quality grapes from there too, and the wines have become over 1 percent stronger,” he continued. Instead, vineyards downhill that used to make grapes for the best wines are experiencing problems, such as prolonged dry spells that can entirely change the quality of grapes.
The changes are happening all over Italy, said Domenico Bosco, who heads the wine producers division of Colidiretti, Italy's biggest farmers' association. Now the increase in alcohol content that results from the lengthening seasons is being seen as a problem.
“Until a few years ago,” Bosco said, “people thought that the more alcoholic a wine was, the better its quality.” In fact, winemakers responded to the demand from consumers for stronger wines by making their wines richer in taste and more alcoholic.
But this, warns Bosco, is now changing. Some consumers have started seeking out lower-alcohol wines for reasons of taste. Meanwhile, new laws in Italy and across Europe have clamped down on drunk driving and alcoholism. Producers, however, are struggling to adapt as forces beyond their control push their wine's alcohol content up.
“In the last 10 years,” said Gabriella Tani, an oenologist from Tuscany, “summers have been hotter and we have had more and more wines with high alcohol content, at 15 percent or more.” This is a problem, she adds, particularly with wine made from Merlot grapes.
Winemakers have a range of options available to fight the effects of climate change. They can water their vineyards more, but with rising temperatures and rain becoming more erratic, in many regions this is not an option. They can harvest the grapes earlier, but sometimes this compromises the taste and quality of the wine.
Or they can try relocating their vineyards further uphill. According to oenologist Francesco Bartoletti, in general “100 more meters [328 feet] of altitude means a loss of about 1 percent in alcohol content.”
While there are vineyards at 4,000 feet in the Alps and even higher on the Etna volcano in Sicily, such an altitude would fundamentally change many Italian wines whose character comes from the place where the grapes have grown for hundreds of years. It also means they would not qualify for Italy wine classification system, which labels wines as DOC or DOCG according to their place of origin and methods of production.
“We might have to change some of these rules,” said Bosco. “Maybe not for the big name wines, but probably for the medium-quality ones or they won't be able to stand up against the competition.”
In fact, climate change is proving favorable for countries such as Germany that have previously been considered too cold for wine-making. For Bosco, “climate change and a taste for 'lighter' wines are helping Continental European wines.” Wines from England and other northern countries hold new promise.
“The future,” said Bartoletti, “will see vineyards move north,” while southern European vintners in traditional wine-producing countries will suffer.
Some say the answer lies in big-scale industrial techniques, such as alcohol removal, already widely employed in countries including Australia or South Africa. France and Spain ― two other big European wine-producers that have to cope with the effects of global warming ― have already made it legal. But in Italy, with its small wineries and its strong emphasis in traditional winemaking techniques, such a technique might be more difficult to accept.
“After all, wine is an agricultural product, not an industrial one, and it can't follow consumers' tastes blindly,” Bosco said. “If you apply an industrial process such as alcohol removal, it's not wine anymore. You'll have to call it something else: maybe 'wine-based beverage.'”