Will the Wine Be OK? With the Napa Fire Raging On, Here's What to Know About California Vineyards

As vintages go, 2017 does not look like it will be a very good year in California's famed Napa Valley.

As of Tuesday, uncontained fires have raged over more than 50,000 acres of northern California's wine region, and Governor Jerry Brown has declared a state of emergency.

Local emergency personnel and winery staff are focused on protecting people first, but multiple vineyards have already been consumed in the blazes. The loss of hundreds of acres of vines will no doubt affect future years' production, but even grapes that have already been harvested may end up with smoke taint, which occurs when finished wine picks up a smoky flavor from compounds absorbed by grape skins during a fire.

The Signarello Estate winery in Napa, California, was damaged by a wildfire that moved through the area, on October 9. As of Tuesday, uncontained fires have raged over more than 50,000 acres of northern California’s wine region. Multiple vineyards have already been consumed in the blazes. Justin Sullivan/Getty Images

California vineyards had a particularly bad experience with smoke taint in 2008, when, fires earlier in the growing season left vines, particularly in Mendocino County, northwest of Napa, bathed in smoke. Vintners are struggling to decide whether their wine was even worth selling.

Smoke taint is more severe in red wines because there is increased contact between the wine and the grape skins during the winemaking process. In theory, smoke taste could be lessened by reducing that contact time. Winemakers can also add an activated carbon compound, according to Kerry Wilkinson, a wine chemist at the University of Adelaide in Australia.

Burned wine bottles at the Signarello Estate winery in Napa, California. There is concern that even grapes untouched by fire might have smoke taint. Justin Sullivan/Getty Images

Cabernet Sauvignon and dessert wine grapes are especially vulnerable to smoke taint because they are typically harvested late in the year, according to James Harbertson, a wine chemist at Washington State University's Wine Science Center.

Smoke is not the only issue right now. The Wine Institute, a group of 1,000 California wineries, said some fermentation plants have been hit by temporary power outages, which could delay grape processing. These could also affect the final wine, John Aguirre, president of the California Association of Winegrape Growers, told Newsweek.

"We've heard reports of wineries in affected areas redirecting harvested grapes to wineries outside of fire-threatened areas, so that those grapes can be processed in a timely manner," he said.

Smoke looms over vines at the Gundlach Bundschu winery in Sonoma, California. Justin Sullivan/Getty Images

The crisis will continue long after the fires are extinguished, experts said. Heat can damage individual vines, even if they aren't burned, and sometimes the damage is permanent, Wilkinson adds. Across Napa County, there are 45,000 acres of wine grapes, almost one-tenth of the county's area.

And of course, the vineyards that have suffered direct fire damage will face steep rebuilding challenges.

"It is very expensive to plant grapes in California, let alone Napa and Sonoma Valley, and very expensive to build anything, not to mention regulations and permits," Harbertson told Newsweek in an email. "The economic losses here can be quite severe."