Viticulturists keep fingers crossed that smoke won’t taint wine

Topography, microclimates play a big role.|

While fires to the northeast and west cast a haze and pollute Sonoma Valley air, vineyard and winery owners are cautiously optimistic that the smoke won’t taint wine grapes, which are vital to the county’s economy.

The wine industry and associated tourism dollars account for about $20 billion in Sonoma County every year, and account for more than $3 billion in wages to wine industry employees, according to Sonoma County Vintners.

“At this point, it's too early to know if there will be measurable impacts on the Sonoma Valley wine harvest. In many areas, much of the smoke was transitory,” said Maureen Cottingham, executive director of Sonoma Valley Vintners and Growers Association. “There may have been some (smoke) in the morning and by afternoon it’s gone. The varied climate and topography of Sonoma Valley is so different that there is no one size fits all answer when it comes to assessing smoke impact.”

Smoke, ’it’s insidious. I hate it. I can taste it in my mouth just thinking about it.’ Phil Coturri, viticulturist and winemaker

Danny Fay, general manager of Kanzler Vineyards in Sebastopol who manages Sonoma Valley vineyards for his own wine label, Hill of Tara, said he is concerned about the effect smoke could have, but said he is an eternal optimist.

“I still feel (the) 2020 (harvest) has a lot of great potential,” Fay said.

Fay hasn’t sent any grapes to be lab tested, but is conducting vineyard tests and microfermentations to determine if there has been any damage yet.

Microfermentations, recommended by UC Davis Viticulture and Enology department, is a subject Anita Oberholster discussed in a Zoom webinar on Tuesday called “What Do We Know About Grape Smoke Exposure.”

Viticulturist and winemaker Phil Coturri said he is conducting microfermentations for his clients, and in at least one case some blocks of a vineyard had smoke taint, while others did not.

“There was definite smoke aromas coming off in that fermentation,” he said.

Smoke blankets a vineyard in Kenwood on Monday, Aug. 31, 2020.
Smoke blankets a vineyard in Kenwood on Monday, Aug. 31, 2020.

Smoke, he said, “it’s insidious. I hate it. I can taste it in my mouth just thinking about it.”

Smoke covered Sonoma Valley and the region in 2017 and invaded Coturri’s personal vineyard. It was an experience he said he learned a lot from, and expects that those lessons will be needed in the future. Climate change is a real thing and it is altering weather patterns, including fire season.

More research is taking place now, especially in Australia where fires raged starting in late 2019, but Coturri said there is not a lot of education out there about smoke, and what it does to wine grapes and juice.

What used to take two to three days to get lab results back is now taking more than twice as long, he said.

Fay likens lab tests for grapes to the time lag in COVID-19 tests – results for a test conducted on Monday, for example, don’t come back for eight to 10 days, and a lot can change in that time.

“The only certainty is uncertainty. It’s 2020 in a nutshell,” Fay said.

Gordon Burns, president of ETS Laboratories in St. Helena – the lab that conducts testing and analysis for vineyards throughout Sonoma and Napa counties – said the lab has conducted “a very significant number of berry and wine samples.”

“The equipment required for the analysis of smoke impact markers” are conducted on instruments which “are highly complex and expensive, and require very specialized folks to run them. Because of this, our capabilities for these analyses are centralized in our Saint Helena laboratory,” Burns said.

“To help our clients through these difficult times,” Burns said they have have shifted most of their testing and analysis of smoke-related markers, “and the instruments are at work 7 days a week and 24 hours per day.”

Some wineries have already pulled the plug on this year’s harvest, said Ellie Ceja of Heirs of My Dream Winery custom crush facility. Ceja said a couple of their clients indicated they are not bringing in fruit, and others have said they are considering that option.

One of Coturri’s clients harvested six acres of pinot noir on Sonoma Mountain earlier than usual because of the possibility of smoke taint. Red grapes such as pinot noir and cabernet sauvignon need more time on vines to ripen, but pinot noir is picked earliest during harvest when used for sparkling wines.

County rules related to coronavirus shelter in place required tasting rooms across the region to only offer service outside. Ceja said the businesses at the 22985 Burndale Road location, where Ceja Vineyards, Hanson Sonoma Distillery, and Troika Wines are located, have suffered during the smoke-filled days.

“We really weren’t feeling the effects of COVID too badly, but once the fire hit… oh my goodness,” she said. “The fires are really playing a big part” in day-to-day business.

Tony Moll of Three Fat Guys Wine said business in the tasting room “has definitely declined since the fires” due to the air quality. Where his tasting room is located there is a “nice breeze that pushes through” and the air there is “pretty decent.”

Smoke blankets a vineyard in Kenwood on Monday, Aug. 31, 2020.
Smoke blankets a vineyard in Kenwood on Monday, Aug. 31, 2020.

In years past when other fires have choked the air, “we just have moved everybody inside,” but that’s not allowed during coronavirus he said.

“All I’m trying to do is keep the doors open and keep my team employed; that’s what we’re down to,” Moll said.

His bigger concern though is “smoke taint, the way that the smoke has been leveling off in the Valley is not good.”

He has sent samples to the lab and is waiting for results. But, he said, he is “overly optimistic” about most things and still holds out hope for a great vintage.

Burns said the region is wide and microclimates and varying topography will play a part in the effects of smoke.

“The current fires cover a very wide area, but only a tiny fraction of that area is planted to wine grapes. Every location is different, and smoke exposure may be transitory and as little as none at all,” Burns said.

Cottingham said the region encompasses more than 1.1 million acres and the combined fires are affecting less than 1 percent of that.

“The great majority of the Sonoma County area is completely unaffected, which of course includes the Sonoma Valley region,” she said.

Burns agrees with Cottingham, that the season is still in progress and there is little cause for alarm at this point.

“It is far too early for anyone to speculate as to the extent of impact in areas where smoke was persistent,” he said.

Coturri said the “bigger” red grape varieties still have two or three weeks to go before harvest and he’s hopeful that the good progress firefighters have made on the fires will bode well. Optimism was high among those interviewed who said it is the sentiment they’ve heard from colleagues, too.

“Our winegrowers and winemakers are focused on ensuring that the 2020 vintage will feature only the highest quality wines,” Cottingham said.

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