How climate change is tweaking the taste of wine

Warming, wild;res and unpredictable weather threaten to disrupt the delicate processes that underlie treasured wines, putting the ;ne distinctions between grapes at risk.

Soon after the devastating Glass Fire sparked in California's Napa Valley in September 2020, wine chemist Anita Oberholster's inbox was brimming with hundreds of emails from panicked viticulturists. They wanted to know if they could harvest their grapes without a dreaded effect on their wine: the odious ashtray 1avour known as smoke taint.

Oberholster, of the University of California, Davis, could only tell them: "Maybe."

Industry laboratories were slammed with grape samples to test, with wait times of up to six weeks. Growers didn't know whether it was worth harvesting their crops. Eight percent of California wine grapes in 2020 were left to rot.

Winemakers are no strangers to the vicissitudes wrought by climate change. Warmer temperatures have been a boon to some in cooler regions who are rejoicing over riper berries – but devastating to others. Scorching heat waves, wild;res and other climate-driven calamities have ruined harvests in Europe, North America, Australia and elsewhere.

And as 2020 showed, climate change can take its toll on grapes without directly destroying them. Wild;res and warmer temperatures can transform the 1avour of wine, whose quality and very identity depends on the delicate chemistry of grapes and the conditions they're grown in. Many growers and winemakers are increasingly concerned that climate change is robbing wines of their de;ning 1avours, even spoiling vintages entirely.

"That's the big worry," says Karen Macneil, a wine expert living in Napa Valley and author of The Wine Bible. "That's the heartbeat of wine – it's connected to its place."