Wildfire and What Comes After: Two Thousand Seventeen to Two Thousand Twenty

October of two thousand seventeen began normally enough for the wine country. The harvest had just come in. It had been a good year.

On the night of October eighth and ninth, wind gusts reached sixty and seventy miles per hour across Napa and Sonoma counties, and a dozen fires ignited simultaneously. The Tubbs Fire came down out of the hills and into the city of Santa Rosa with a speed that outpaced evacuation orders. More than five thousand structures burned in Santa Rosa and the surrounding communities. The Nuns Fire moved through Sonoma Valley, damaging or destroying multiple historic wineries. The Atlas Fire burned simultaneously in Napa County. Forty-four people died in the October fires, according to Cal Fire's official count.

What the fires introduced to the wine industry went beyond direct destruction. Vineyards miles from any active flame, in counties that did not burn, produced grapes that made undrinkable wine. The cause was smoke taint: the absorption by ripening grapes of volatile phenols produced by burning vegetation, which bind to sugars and release a medicinal, ashy flavor during fermentation. A vineyard does not have to be touched by fire to be ruined by it. Smoke drifting across a valley on the wrong day in October can destroy a harvest.

Three years later, the two thousand twenty fire season was worse. The LNU Lightning Complex, ignited by a lightning storm in August, became one of the largest fires in California history, ranking around seventh by acreage, and burned through Lake, Napa, Sonoma, Solano, Yolo, and Colusa counties.

The industry has adapted. Winemakers now harvest earlier, before smoke can accumulate in the grapes. Trellis systems have been redesigned to reduce leaf surface exposure. Air filtration has gone into processing facilities. None of this changes what is happening to the climate driving the fires.

The same thermal geology that makes Calistoga's mud baths possible, the same Mayacamas watershed that gives Napa Valley its microclimate, the same fog pattern that moderates summer heat in Sonoma: all of it is being slowly altered by a warming that lengthens fire season and reduces the snowpack that historically regulated harvest timing. The valley rebuilt after phylloxera. It rebuilt after Prohibition. The question the industry is beginning to sit with is whether a third rebuilding is structurally possible when the thing being destroyed is the climate itself.