French winemaker Gregory Guibergia ran his hand over the crackling vine leaves at the edge of his vineyard, relieved the recent wildfire hadn’t destroyed everything. But his relief was mixed with worry. Would the smoke ruin this year’s wine?

The last row of vines in his southeastern France vineyard tells the story. Brown, heat-damaged leaves rustle in the wind, a reminder of the blaze that swept through the region this summer. Further away, the plants look healthier, with enough green leaves for the grapes to ripen before next week’s harvest.

Guibergia knows he’s been lucky. Several wildfires tore through the surrounding Var region in recent weeks, forcing thousands to flee their homes. Among them was Hollywood star George Clooney and his family. The fires destroyed more than 6 000 hectares of land.

But the damage might not be over. “The big question is whether or not we will have a burnt taste during the winemaking,” Guibergia told AFP. “We won’t know straight away.”

Smoke damage threatens harvest

He’s not alone in his concern. France’s main rosé-producing region has seen flames destroy hundreds of hectares from roughly 30 000 hectares of vineyards, according to expert estimates.

Guibergia has been making wine for 25 years. He plans to pick the grapes and process them in separate batches, hoping to limit damage from any contaminated fruit. But he’s worried. If the wine from his 25-hectare vineyard in Correns is declared undrinkable, he won’t be able to sell around 90 000 bottles.

Waiting for laboratory results

Across the region, experts are testing grapes to determine if they’re still good for winemaking.

“An hour or two of exposure is enough to trigger glycosylation, or the binding of smoke to the sugars in the grapes,” said oenology consultant Clement Prelat, who is advising local winemakers. “This smoky taste will only reveal itself after fermentation.”

Lucie Demirdjian, a winemaker in the neighbouring village of Ponteves, is waiting for lab results before she starts harvesting. She lost 11 of her 18 hectares in a wildfire and doesn’t want to waste money harvesting the surviving vines if the wine will be tainted.

“We know what to do for frost or hail, but not wildfires,” she said. At least “we can detect the precursor of the smoky flavour beforehand”.

Chemical solutions may help

Agricultural engineer Gregori Lanza said only vineyards covered in fire retardant by firefighting planes have been declared unfit for winemaking so far. The retardant is a chemical mixture used to stop fires from spreading.

Wine with a smoky taste wouldn’t necessarily be unsafe to drink, but it would struggle to sell. “It’s not a sought-after taste in wines, so even if they’re still drinkable, they won’t be marketed,” Lanza said.

Fabien Mistre, from the Correns winemaking cooperative, said producers in another part of southern France tested some techniques after a wildfire last year. “Activated charcoal can remove the smoky taste from rosé and white wine,” he said.

Mistre is hoping his organic wine will come through the fires unscathed, but he’s waiting until the winemaking process is complete before he knows for sure. Even though insurance won’t cover business losses from taste changes, he won’t sell wine that smells burnt.

“It would be like smoked ham,” he said.

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