North Coast wine industry now faces smoke taint threat during annual harvest

As he stood on a hill on his vineyard that offered a 360-degree view below of the Russian River Valley Tuesday before dawn, John Bucher could see the faint orange glow of the Walbridge fire 6 miles away.

Even with fire crews making progress to stem its growth, the 54,500-acre fire represents the most significant threat to the Sonoma County wine industry during the 2020 harvest that started three weeks ago amid the turbulence of the coronavirus pandemic.

The fear now is not so much over the burning of structures or the havoc caused by fire-related evacuations. It’s the lingering smoke that could taint the wine grape crop and further shrink a less bountiful vintage expected this year.

“We’re all nervous where this fire is going to go and what is going to happen,” said Bucher, as he looked toward the crew busy picking 13 tons of pinot noir grapes in the early morning hours for Papapietro Perry Winery in Healdsburg.

As he spoke the skies were clear, making the stars visible. There also was a little trace of the “pretty dismal” smoke he said had been much more prevalent Monday morning.

“We have been really fortunate. ... There really hasn’t been much movement,” Bucher said of the wildland blaze centered in mountainous terrain west of Healdsburg. But he was especially happy because he planned by Wednesday to bring in the last of his valuable pinot noir crop that he’s grown on his 55 acres.

“Part of it was that we pushed hard to get everything in, whether it was because of the heat or now because of the potential of smoke and ash issues,” he said.

Throughout the region there is a similar drive to speed up harvesting as a result of the smoke threat that could severely affect the North Coast grape crop that in 2019 was valued at $1.7 billion.

Daniel Chavez of Daylight Vineyard Management, whose crew picked the Bucher fruit, said he’s been getting calls from more winemakers saying “we need to pick within a day or two.”

In past years during mid-August, Chavez said they would be typically wavering over whether they were satisfied with sugar levels in the grapes and not be so insistent.

To identify potential smoke taint, winemakers are taking grape samples to local laboratories to test for chemicals — specifically guaiacol and another related compound, 4-methyl guaiacol — that give off foul flavors during fermentation. One local lab, ETS Laboratories, said on its website “some samples are experiencing slight delays in processing times“ because of the demand. There has been more talk among area winemakers of picking fruit early and turning the wine into a rosé because the skins soak for a limited time, Bucher said.

Major wildfires have been a factor in the North Bay during the past five years, but they typically have come later in the grape growing season, in October when there is less than 10% of the fruit on the vines, as opposed to the start of the season with this year’s fires.

“It’s very difficult to predict, but this definitely has the potential to have a wider impact and impacting more farmers and definitely more wineries,” said Anita Oberholster, an associate specialist in the cooperative extension in enology at UC Davis and an expert on the issue of smoke taint. “This is really the last thing we needed.”

Oberholster said research on the subject is still in its infancy and there are no easy answers to provide. “I get a lot of questions from growers and winemakers wanting to know ’What do I do? Do I pick? Do I leave it?’... and we just don’t know,” she said.

Prior to harvest, she suggested winemakers conduct a small-batch winemaking with a five-day fermentation to determine if there are foul odors or taste in the liquid from suspected grapes.

“That is really the best predictor we have at the moment and what we’re really trying to convince the industry to do,” Oberholster said.

The responses from North Coast wineries are varied, said Brian Clements, a partner at Turrentine Brokerage, a wine and grape brokerage in Novato. Some have sent letters to growers indicating they are going to test for smoke taint. Others are still formulating a plan, while a portion have a wait-and-see attitude depending on how much smoke has permeated a particular wine region.

“Each winery is doing what they feel is necessary to ensure quality wine in their tanks,” Clements said. “It’s kind of pins and needles right now.”

Dry Creek Vineyard plans to start its harvest on Wednesday with a pick of sauvignon blanc grapes, said Kim Stare Wallace, president of her family’s winery in the Dry Creek Valley. The winery’s vineyards are on the valley floor and they have not been affected as much with smoke as hillside locations around Lake Sonoma, Wallace said.

“We’re super, super lucky with our location,” she said.

Some growers may have crop insurance that could cover losses, although such policies are not widespread in the region, said Jeff Okrepkie, who writes policies for wineries at the George Petersen Insurance Agency in Santa Rosa.

Wineries that don’t have estate vineyards could be left exposed in trying to secure grapes elsewhere as a result of smoke taint. That will be especially problematic in regions where there have been extensive smoke exposure — such as the Rockpile wine region near Lake Sonoma — that may leave few alternatives to source fruit for this year’s vintage, Okrepkie said.

“The people who buy those grapes ... there’s no recourse for them,” he said. “There’s a ripple effect. There is so many things that can go wrong,”

You can reach Staff Writer Bill Swindell at 707-521-5223 or bill.swindell@pressdemocrat.com. On Twitter @BillSwindell.