During the wildfires of 2020, California vintners lost billions of dollars by letting grapes die on the vine — and grapes are the highest-value crop in the United States. That’s all according to the Department of Agriculture.
Anita Oberholster, a professor of viticulture and enology at UC Davis, is leading an effort to help the wine industry adapt to wildfires.
She explains that when wood burns in a wildfire, it decomposes into compounds called volatile phenols, which can penetrate into the skin of grapes. Then in the winemaking process with those grapes, the compounds are released — causing a smokey smell and ashtray-like aftertaste when you swallow the alcohol. The taste also isn’t the same as smokiness derived from toasted barrels that some wines are aged in.
So far, researchers are most concerned about smoke that wafts onto vineyards within 24 hours. Thus, Oberholster is optimistic this year’s crops won’t be as drastically impacted.
How can vintners protect their grapes? The first task is to determine whether or not grapes have actually been smoked. Oberholster contends that perhaps some 2020 grapes would have made good wine. Next, farmers can explore whether any barrier sprays can keep the smokey compounds away from the fruit.
“We're looking at … things that [are] already approved and actually used in vineyards for other purposes,” she explains. “A lot of these things are insoluble, they don't make it into the final wine, or they break down and it doesn't impact the taste at all.”
Other alternatives include growing grapes indoors, which can be expensive, or relocating vineyards to areas that are not impacted by the smoke.
And amid climate change, she says, “If you get increasing temperatures as projected, then we will get to a point where we need to start growing other varieties, and other wine growing regions, or climates, may become more positive or better for grape growing. And there may be a movement where other areas become as popular as Napa and Sonoma.”