Wildfire smoke hasn’t tainted this year’s grape harvest – yet

Around Washington this summer, wildfire smoke has reduced air quality and blocked out many beautiful views. Fortunately for Washington winemakers, it has yet to affect this year’s grape harvest, though that could change depending on how the rest of the wildfire season plays out. Photo: Agne27

Washington wine lovers will be pleased to know that the wildfire smoke inundating the skies and reducing air quality over much of the state hasn’t ruined the grapes from this year’s impending harvest. However, the intensity, location and duration of wildfires over the next month could change that.

In early August, smoke from wildfires in British Columbia poured over Washington state, deteriorating the air quality in many areas. The state has also had numerous wildfires that have burned over 136,000 acres.

And yet, wine experts say that the smoke hasn’t wrecked the grapes.

“We’ve had people concerned, but I’ve not tasted any wines that have been smoke tainted,” Washington Association of Wine Grape Growers Executive Director Vicki Scharlau said.

Wildfires have been a major concern for grape growers since California’s 2008 wildfire season, when 1.3 million acres burned and the state experienced record levels of air pollution. For many California vineyards that year, the wildfires left their grapes smoke-tainted.

Washington is a major wine-producing region, featuring 900 wineries that contribute approximately $2.1 billion to the state economy. Last year, 350 growers harvested 270,000 tons of grapes and produced 17.5 million cases of wine. Like California, it has also faced record-setting wildfire seasons in recent years.

Tom Collins is an assistant professor at Ste. Michelle Wine Estates Wine Science Center at Washington State University’s campus in the Tri-Cities. While smoke levels haven’t been high enough to taint this year’s grapes, he told Lens that “it’s not known yet” whether that will still be the case at the end of the wildfire season, because there’s “still plenty of time for more smoke and more fires before we get through this harvest.”

Although they’re still studying the effects of smoke on grapes, he said that the “general thinking right now is the risk for smoke taint in the fruit and in the wine is lower when you have smoke exposure before the start of ripening.”

The wildfire smoke from Canada in early August arrived before most grapes ripened, a process also known as “veraison”. Measurement tools used to gauge smoke levels showed it was “relatively low,” Collins said. “I know they looked terrible, but the actual amount of particulate matter (from the smoke)…was fairly low.”

However, the statewide harvest impact may be hard to determine, he added. Smoke taint is more of an issue with taste preference and not usually a health concern.

“The wines that have noticeable smoke taint … in many cases it’s sort of self-limiting,” he said. “There’s not really a sharp dividing line between ‘this wine is fine’ and ‘this wine is not.’”

The smoke taint “in part depends on timing,” he added. “The risk goes up. But it also depends on the intensity and duration. If you have it for a short period of time and it’s not intense, you may have a little bit of (smoke) effect but not enough to preclude you from making wine that is sellable. If it hangs around for 10 days, you may not be able to do anything with it.”

Jack Delvo is a winemaker with Bergdorf Cellars, a Leavenworth-based winery that uses grapes grown throughout Chelan County and Columbia Valley. He told Lens that whether a wine is considered smoke tainted, i.e. not sellable, “all depends on the individual winemaker.” So far, the wildfire season hasn’t affected them as it did in 2012 when the Cashmere Fire burned 2,600 acres near one of the vineyards.

Winemakers will often add a smoky aroma to their wines through aging in oak barrels, he added. However, unlike wildfire smoke, the process and exposure is controllable.

Another reason the effects of wildfire smoke will be difficult to gauge is that their severity isn’t as relevant as their proximity to a vineyard, the duration of the smoke levels and how intense that smoke is, Collins said. Several vineyards located near the same wildfire may have wholly separate smoke levels.

“The fact that we have fires routinely means that there are areas that will be affected routinely,” he said. “It really comes down to that right set of combinations.”



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