Marketplace

California winemakers try to save grapes tainted by smoke from wildfire

Like nearly everything in California, the state’s wine industry — with an estimated retail sales value of $43.6 billion in 2021 — faces another hot summer of drought and potential wildfires. But when the forests burn near California’s wine country, it’s not just the flames that threaten the vineyards; it is also the smoke. Grapes exposed to wildfire smoke can produce an ashy and bitter wine, forcing winemakers to leave millions of dollars on the vine.

Now, Santa Cruz scientists are helping the industry deal with this dilemma, with a unique approach that can detect smoke from grapes. They say the results will allow winemakers to better predict whether the grapes are worth harvesting or better left to rot.

“It’s a huge problem for the wine industry,” said Prudy Foxx, a winemaker in the Santa Cruz Mountains.

This was especially true in 2020, when the catastrophic wildfire season led winemakers to cancel more than $600 million in contracts with grape growers, fearing fruit exposed to smoke could produce unsaleable wine.

Phil Crews, an organic chemist at UC Santa Cruz and owner of the Pelican Ranch Winery in Scotts Valley, turned to Australia, where winemakers have been battling the impact of smoke in wine for nearly two decades. . He applied a method developed by the Australian Wine Research Institute to California wines.

This method is unique, he said, because it provides an accurate measurement of the smoke particles in the wine that lead to the smoke smell.

The smoke-tinted wine bottles are in the early stages of smoke analysis at SC Labs. (Jerimiah Oetting/KAZU News)

When grapes are exposed to smoke from a forest fire, the ash-tasting compounds that are absorbed into the fruit bind to sugars. Crews said the smoke particles are so entangled with sugars that the grapes don’t even smell of smoke.

Everything changes once the juice is drunk. Enzymes that begin to break down food in saliva tear these molecules apart, releasing the smoke particles again and causing a bitter, ashy taste.

Directly measuring sugar-bound smoke particles is the surest way to know how wine will end up, Crews said. “I knew how to do it, but I couldn’t do it in my research lab. So I ended up teaming up with the folks at SC Labs.

SC Laboratories is a private laboratory in Santa Cruz that tests another California crop: cannabis, which it has been testing in California for over 12 years. The company now has labs in Oregon and Colorado.

“Cannabis and wine are produced in the same regions,” said Jeff Gray, CEO and founder of the company. “And, unfortunately, they are subject to the same environmental factors. Wildfires are now the norm here in California. »

Wine analysis is not a central objective of the laboratory. But because they had the equipment and expertise Crews needed for his study, Gray saw an opportunity to try something new.

Mass spectrometers at SC Labs.
SC Labs mass spectrometers can detect impurities at the molecular level – in cannabis or wine. (Jerimiah Oetting/KAZU News)

“I think we’re just scratching the surface,” said Paul Dorenbach, principal analyst at SC Laboratories and co-author of the Crews study, published in March. He said they measured more than 250 samples between 2017 and 2021.

“As we test and geolocate these samples, we can get a library of reference levels for all of these wines,” he said. This library will help winemakers interpret the number they receive, placing their wine on a spectrum between heavily smoky and clean and sparkling.

The methods and results of the study are freely available. Crews said he wanted to create an open source way for more labs to replicate the analysis, so the wine industry is better prepared for the next big wildfire year.

“We want a lot of labs doing this rather than one or two,” Crews said.

Prudy Foxx, the grape whisperer, says wine ultimately comes down to taste — and what wine critics think.

“We’re going to learn a lot about how this wine goes through the market,” she said. “If critics choose to block anything where they detect even smoke impact, it will affect the industry.”

The wine is also infinitely complex, Foxx added, and a slight impact of smoke could add another interesting layer – a memorial to the fires of that year. Or a bitter reminder that the anger of climate change grows heavier with each vintage.

There’s a lot going on in the world. Through it all, Marketplace is there for you.

You rely on Marketplace to break down world events and tell you how it affects you in a factual and accessible way. We count on your financial support to continue to make this possible.

Your donation today fuels the independent journalism you rely on. For just $5/month, you can help maintain Marketplace so we can keep reporting on the things that matter to you.