Climate Solutions

This experimental vineyard seeks to save wine from climate change

Eugénie Baccot/Divergence

Since Romans brought the first grape vines to Bordeaux, wine has been the lifeblood of this region in southwest France. It has survived invasions by Vandals and Visigoths and an infestation by an American aphid. It was served to royalty and sought by pirates. Now, it’s a billion-dollar industry.

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But the 2000-year-old tradition faces a planetary threat: climate change. Rising temperatures and unpredictable weather affect the growth of grapes and alter the wine they produce.

Vintners fear that further warming will upset the delicate equilibrium between sweetness, acidity and aromatics that make Bordeaux wine distinctive.

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At an experimental vineyard on the outskirts of the city, scientists are seeking ways to help Bordeaux winemakers adapt.

Eugénie Baccot/Divergence

Portuguese and Greek vines are used for climate experiments at the University of Bordeaux, France.

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American scientists examine the leaves' sizes on the vines.

Eugénie Baccot/Divergence

Eugénie Baccot/Divergence

Average annual temperatures in Bordeaux have increased by almost 3.6 degrees Fahrenheit since the middle of the last century, according to France’s meteorological service. A heatwave in summer 2019 sent mercury soaring to a record 106 degrees. That year, wine production across the country fell more than 10 percent.

“People are starting to prepare themselves to face much more difficult conditions to grow grapes and create good wines,” said Nathalie Ollat, an agronomist at the National Institute of Research for Agriculture, Food and Environment.

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One central challenge of climate change is that it increases the sugar content of grapes. When their juice is fermented, more sugar will be converted into alcohol, resulting in a drink that is far too boozy. Sugary grapes are also less acidic, which can accelerate the aging process and affect the wine’s flavor.

Eugénie Baccot/Divergence

Eugénie Baccot/Divergence

Eugénie Baccot/Divergence

Bordeaux wines are typically made from three varieties of French grapes. But the institute’s experimental vineyard boasts more than 50 other types from southern France, Greece, Portugal and elsewhere. Ollat and her colleagues are studying these warm-weather adapted plants in hopes of finding varieties that taste traditional but can tolerate heat.

Eugénie Baccot/Divergence

Scientists are also mapping microclimates in the Bordeaux region — pockets of land on the north slopes of hills, or on the cool banks of rivers — where farmers might find better conditions for grape growing.

“It’s important to show the growers that even remaining in the same place they have some solutions,” Ollat said. “Considering the different varieties, using other growing practices, but also to choose the best parcels and plots.”

Eugénie Baccot/Divergence

Eugénie Baccot/Divergence

Engineer Emilie Bruez (right) studies the effect of pruning on the yield of Cognac vines.

Eugénie Baccot/Divergence

Eugénie Baccot/Divergence

Eugénie Baccot/Divergence

Inside the institute’s expansive laboratory, researchers investigate ways to adjust the winemaking process after harvest. One team is looking for yeast strains that use more sugar to produce the same amount of alcohol, mitigating the problem of grapes that become ultra-sweet from heat.

Eugénie Baccot/Divergence

Meanwhile, economists are studying consumer willingness to buy Bordeaux wines that don’t taste traditional — either because of climate change, or because of growers’ efforts to adapt.

One study of blind taste-testers found that people enjoyed one glass of wine grown under warmer conditions, but were less likely to buy an entire case.

Eugénie Baccot/Divergence

Eugénie Baccot/Divergence

Engineer Cecile Thibon starts a micro-vinification, or the conversion of grape juice into wine, as part of an experiment.

Eugénie Baccot/Divergence

Eugénie Baccot/Divergence

“Growers ... may be interested in change, but they need to know if they will be able to sell the wines,” Ollat said. “This is the reason why we try to suggest adaptation, in order to keep the style."

Eugénie Baccot/Divergence

The institute is also studying ways to cut back on the water and fossil fuels used by the wine industry.

“Climate change is a threat” to winemaking, Ollat said. But by changing its own practices to fight warming, maybe the industry can help save itself.

Eugénie Baccot/Divergence

Eugénie Baccot/Divergence

Eugénie Baccot/Divergence