From fire to fallout: CZU’s lasting impact on Santa Cruz County’s wine industry

High in the Santa Cruz Mountains and surrounded by redwoods, it’s difficult to see evidence of the CZU Lightning Complex fires that destroyed Big Basin Vineyards five years ago. Trees surrounding the vineyard have grown back, the winery and tasting room reopened, and 600 damaged vines were replanted and are thick with verdant leaves. 

But the fires still haunt Big Basin Vineyards owner Bradley Brown. For five years, he tried to save 2,000 cases of wine from his 2020 vintage, which he spent more than $250,000 to produce. Unknown to him at the time, Brown made the wines from grapes that had been marred by smoke from the fires. After years of trying to remove the muddy taste they left in the finished wine, this summer he finally threw in the towel and tossed out the whole vintage.

Smoke taint, as it’s known in the industry, affected nearly all of the grapes in the region to varying degrees. The cloying molecules are impossible to rinse off the delicate grape skins and leave unpleasant flavors in the wine, ranging from ashtray to burnt toast. 

The 2020 harvest season and the years that followed became a crash course in identifying numerous chemicals found in smoke and their varied effects on wine. While that information will be invaluable should another wildfire strike the area, it was earned at great cost by local winemakers and producers who lost grapes during the harvest season or had to later destroy cases of spoiled wine, at a loss of hundreds of thousands of dollars. Five years later, some winemakers are still feeling the financial toll. 

When the CZU Lightning Complex fires tore through the Santa Cruz Mountains in 2020, they destroyed more than 86,500 acres and damaged Brown’s winery on a remote ridge above Big Basin Redwoods State Park. Flames melted an irrigation line, scorched a mile-long fence and incinerated storage buildings filled with large equipment worth hundreds of thousands of dollars, including tractors, four-wheel all-terrain vehicles, a front loader and a crawler. Brown’s home, located on the property, also burned almost to the ground. Along with two decades’ worth of memories and all of Brown’s belongings, the house held a quarter-million dollars’ worth of wine inventory. 

The flames licked the outer edges of his vineyards, but most of the vines survived, heavy with grapes just weeks away from harvest. “Vineyards don’t burn; they singe,” said Brown. “There is so much water in a grapevine you cannot burn it. You can take a cutting off a vine and throw it on a raging fire, and it will be there an hour later.”

Most of his vines survived, but were the grapes usable? Brown wasn’t sure, and he and other area winemakers faced difficult and urgent decisions about whether to use the visibly untouched but possibly corrupted fruit for winemaking. 

At the time, not much was known about smoke taint. Winemakers in Santa Cruz County didn’t know how close a wildfire had to get to affect vineyards, or how it might change a finished wine. The Santa Cruz Mountains American Viticultural Area – the region’s official geographically defined winegrowing area – stretches along the Central Coast from Half Moon Bay to Watsonville, dotted with 1,500 acres of vineyards and more than 60 wineries. Although the fires held the northern end of the AVA in their grip, members of the local wine industry held out hope that grapes in Corralitos and the southern end of the mountain range could be saved. 

“The big picture for me was coming to realize how ill-prepared we were for figuring out what the impact of the smoke was. It was a big learning curve,” said Prudy Foxx, a well-known viticulturist and consultant based in Santa Cruz. She thinks of herself as a matchmaker between vineyards and winemakers, and advises them on how to produce the best wines possible from each vintage, depending on the qualities of the grapes. 

Foxx has worked with hundreds of vineyards throughout the Santa Cruz Mountains over the course of her 40-year career. When the fires struck, she raced along mountain roads, “madly taking samples” of grapes, she said, to be tested for smoke. 

Nobody wanted to believe they were going to lose their whole harvest, especially if they felt they were a safe distance away from the fire, said Foxx. “There wasn’t really good [fire] insurance in place for vineyards then. There weren’t a lot of great options for people.”

Although the wine industries in Napa, Sonoma and Australia had been badly affected by the Sonoma Complex fire in 2017 and the 2019 Australian bushfires, respectively, 2020 was the first time smoke heavily impacted Santa Cruz County’s wine industry. 

At the time, winemakers sent samples of the juice from the crushed grapes to ETS Labs, an independent laboratory in St. Helena that performs chemical analyses for wineries, breweries and distilleries. ETS tested the samples for one chemical indicator for smoke taint – guaiacol – and the amount detected was recorded on a numbered scale. If a sample went over a certain threshold, testers believed the smoke would be noticeable to drinkers. 

That turned out to be a rudimentary view, said Foxx. Guaiacol is created when wood is burned, so it can indicate smoke contamination. But it’s also created intentionally in winemaking by toasting the inside of oak barrels for aging wine because it adds sweet, woodsy, vanilla-like flavors. It was difficult to understand what level of guaiacol would have a negative versus positive effect. 

She came to realize that there are huge differences in how smoke can present itself in wine, with flavors ranging from campfire to barbecue, to a dullness or lack of flavor. Some of these flavors are more deleterious than others, while others could be incorporated into the wine’s overall flavor profile. Rich smoky flavors in a syrah, for example, might be desirable. For that reason, she believes that “smoke impact” is more accurate than “smoke taint.” 

Foxx began asking labs to test for six different chemical compounds to determine which flavors might be in a finished wine, in the hopes of gaining a clearer picture of how local grapes were affected. When ETS became backed up for weeks due to a wave of vintners requesting tests on their wines, Foxx and local winemaker John Benedetti of Sante Arcangeli Family Wines began testing the grapes on their own to determine whether they could harvest certain vineyards. 

A few weeks before the grapes were ripe, Benedetti would harvest, crush and quickly ferment a small amount of fruit from possibly smoke-impacted vineyards in 5-gallon buckets in his kitchen, and he and Foxx tested them through taste and smell. 

The ad hoc process was effective. “In some cases, you could smell it in the bucket – it smelled like an ashtray,” said Benedetti, but other batches smelled and tasted fine. Those were sent to the lab, and a few weeks later, the growers would have their results by the time the fruit was ripe.

Ultimately, Benedetti, Foxx and other area winemakers discovered a hard truth: that even minimal exposure to smoke muted the wine’s flavor, creating a muddy profile even if the wine didn’t taste obviously smoky. The effect was especially noticeable in delicate varieties like pinot noir, a favored grape in the Santa Cruz Mountains, and became more pronounced over time as the wine aged, dulling desired flavors. As a result, it’s difficult to find Santa Cruz County wines from 2020 on shelves in 2025. Wineries made an effort to sell those wines quickly before the smoke damage was noticeable, if they made the wines at all. 

Red wines made from grapes like pinot noir and cabernet sauvignon were nearly impossible to produce because they require extended contact with the grape skins to create the rich color and extract tannins. But that year, smoke contaminated the skins. White wines like chardonnay fared better, because the juice is pressed off from the skins immediately after harvest, limiting contact with the smoky chemicals. 

Some winemakers got creative and experimented with new winemaking styles in order to work around the smoke effects. Benedetti made a white pinot noir for Lester Estate Wines in Aptos, a winemaking style that’s popular in Oregon but rare in the Santa Cruz area. Other winemakers quickly harvested their unripe grapes early before the smoke damaged them and made sparkling wine, which requires grapes to have lower sugar content compared to non-fizzy wines. 

And almost everyone made rosé from their red grapes, another winemaking style that separates the juice from the skins. The style stuck around in the years following when drinkers and winemakers discovered they liked the lighter wines, said Foxx. “It’s much more common to see a version of rosé made of virtually every varietal that’s out there” compared to before the fires, she said. 

But when Brown harvested Big Basin Vineyards’ syrah grapes in the fall of 2020 to make rosé, he wasn’t so lucky. “The grapes were so badly smoked, the juice smelled like a barbecue coming right out of the press,” he said. 

The fruit at his own vineyards was too contaminated, so Brown purchased additional grapes from other vineyards to make wine that year from vineyards in the southern Santa Cruz Mountains and the Gabilan Range in Monterey and San Benito counties that he hoped were well away from the smoke. 

For the first year, he didn’t detect any impact on the wines. But after the fermentation process and barrel-aging was complete, Brown began to notice that the wines tasted lifeless — the smoke molecules muted the natural flavors of the wine. 

It was a huge disappointment, but not entirely a surprise. Smoke impact can become more pronounced after the first year, and typically gets worse as time goes on. Brown attempted to save some of his wines by filtering out the smoky chemicals, an untested process that ultimately didn’t work in practice. “It seemed to make it better at first, but then it came back later,” he said. 

This year, he faced the reality that the vintage was a total loss. 

In retrospect, he wishes he had been more conservative in selecting grapes that year, and not thrown good money after bad to save the spoiled wine. “Not only did I spend a quarter-million dollars on fruit and bottling wines that I had to send to the crusher, but I also don’t have those wines to sell,” he said. 

That hit comes at a time when the wine industry as a whole is facing a dramatic downturn, largely the result of changing drinking habits. Big Basin’s estate tasting room reopened in 2021, but sales are down like they are throughout the state, said Brown. 

The experience led him to reinvest his energy into Big Basin’s three-year-old tasting room in downtown Santa Cruz. That space offers sharable tapas plates paired with its wines, and food revenue there has grown, he said. 

It wasn’t the only lesson learned from the fires. Brown spent years battling with adjusters over insurance. In 2023, he successfully sued Allied Insurance Managers, the company that insured his winery, after it attempted to reduce his coverage. But there was nothing he could do to recoup other uninsured losses, such as $100,000 in vineyard management fees for his vineyards to grow fruit that had to be cut to the ground. 

His experience wasn’t unique. After 2020, more than 600 wineries in the state lost their fire insurance, and many saw the amount covered shrink while costs increased dramatically. 

Photos that Foxx took at certain vineyards days before the fires struck became crucial evidence for later insurance claims, and now she takes care to photograph vineyards that she works with throughout the growing season. She puts in addendum in all her contracts with winegrowers she works with that discusses the risk of fire, and who is liable to pay for damaged grapes. “That was something none of us had thought about prior,” she said.

The greatest takeaway is that smoke impact is huge and very difficult to protect against, Foxx said. The best thing wineries can do is have a backup plan in order to respond quickly, and to be willing to let go of the harvest if necessary. 

The vineyards themselves send a lasting message of resiliency. “They get scorched and smoke-tainted, but they remain standing,” Brown said of his vineyard. “Our vines were producing the next year, and we made some really good wines in 2021.”

FOR THE RECORD: The CZU Fires destroyed 600 vines at Big Basin Vineyards in 2020.

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