MONTEREY – The nearly $190 million wine grape industry in Monterey County is dealing with the prospect of “smoke taint” in this year’s harvest due to nearby fires, and it does not leave growers many options.
“This was lining up to be an excellent season,” said Kim Stemler, Monterey County Vintners and Growers executive director. “It’s been really good so far with a mild winter, enough water … this was going to be a good harvest.”
But with the recent River Fire outside of Salinas, the Carmel Fire in Carmel Valley and the ongoing Dolan Fire moving east from the Big Sur area, smoke taint has become a major concern for wine grape growers in the county.
Smoke taint occurs when grapes are exposed to wildfire smoke which releases aroma compounds called volatile phenols that can be absorbed into the skin of the grapes and bond with the sugars inside to form glycosides. Once the phenols bond with the sugars, the smokiness cannot be detected by taste or smell. But during the grapes’ fermentation, the glycosides are broken down and the smoke can once again be detected.
Smoke taint is not the typical smoky profile often associated with wines that are aged in charred oak barrels.
“The biggest problem with smoke taint is ‘ashtray,’” said Jason Smith, owner of Valley Farm Management in Salinas. “It may smell OK but the back of the mouth gets the ashtray.”
Valley Farm Management has been growing wine grapes in Monterey County since 1973. Smith’s family once bottled their chardonnay and pinot noir under the Paraiso label.
Local growers, such as Smith, are racing the clock to determine if they should continue to pour money and labor into crops that may already be doomed. Testing for the level of smoke taint in wine grapes is taking longer to get results as hundreds of growers throughout the state flood the limited number of labs available for reliable testing.
The wine harvest is about two weeks late this year. In a normal year, it would be in full swing starting in late August with whites and moving through to late October with reds. Currently, less than 10% of wine grapes have been picked when normally 30% to 40% would be picked already, but growers are waiting for lab results.
“Because of the fires in the last three to four years in the north, there is a lot more known, but there are also a lot of unknowns with big impacts,” said Smith.
He likened the availability of adequate testing to what has happened with labs available to process COVID-19 tests which has also seen backlogs in getting results.
“In order for us to know what levels of smoke taint are in our vineyards, we need labs to do analysis,” said Smith.
Tasting the grape berries, or gauging the amount of ash that blankets a vineyard is no indication of what lies beneath because the smoke permeates the skins of each berry. Grapes can seem fine, but smoke taint comes through months later in the finished wine.
“Many of us are doing our own micro fermentations and then able to do our own sensory analysis,” said Smith.
The West Coast Smoke Task Force, a group formed by industry leaders and three West Coast wine grape growing associations, advises using micro fermentation along with lab analysis to evaluate the presence of off-aromas and ashy flavors.
“This method is most accurate as a predictor of risk when used closer to harvest,” said the task force in its Micro Fermentation Protocols paper published in August.
Valley Farm Management has about 2,000 acres in Monterey County and has sent 50 tests from various vineyards from Gonzales to Bradley. It is one grower among many others throughout the state who are using one main lab and a couple of small labs for testing.
“We just don’t have the results back in a timely fashion,” said Smith.
What was a 24- to 48-hour turnaround time now takes three to five weeks. And it is not just California wine grapes in need of testing but many other wine grape growing regions throughout the world which are experiencing their own problems with wildfires.
Vintners in Australia’s Hunter Valley, for example, estimate that much of their 2020 harvest was lost to smoke taint.
Smith said that a conservative estimate of about 25% of the wine grape acreage his company farms in Monterey County will not be usable.
“We are a chardonnay and pinot noir county,” said Smith. “Chardonnay has been OK, but pinot noir has been devastated.”
Smoke taint is less of a factor in white wines since the smoke compounds are concentrated in the skin of the grapes. Whites do not typically sit on their skins during fermentation as reds do.
“The color in reds comes from fermentation from skins of the berries,” said Smith. “Pinot noir is a much more delicate variety and even in good times it is a difficult variety in winemaking.”
Smith estimates that overall in the Santa Lucia Highlands, 75% to 90% of those wine grapes may be rejected because of smoke taint.
Though most growers have crop insurance, coverage comes to about 50% to 60% of the cost of growing, debt service, and many other factors that go into what was Monterey County’s eighth-ranked crop in 2019 with wine grapes covering 44,683 acres, producing 132,000 tons, and attaining a value of $186,096,000.
Two vintners in Northern California have sued their insurance companies for refusing to cover wines that were damaged by smoke from the 2017 wildfires there.
“You can only honor claims tested from certified labs but there is only one in the entire country, ETS, and their capacity is 250 tests a day,” said Stemler.
ETS, based in St. Helena, is considered one of the most advanced wine laboratories in the world. In existence since 1978, the lab has developed new methods of analysis and new technologies to support the winemaking industry.
It has seen a surge in tests from all over and is working on getting caught up on its backlog.
Monterey County wine grape growers are working with the wineries they have contracted with to determine a course of action, but some may be dropping contracts.
Smith said that even with lab results, wineries may err on the side of rejection rather than take in a product that may not be good.
As climate change and the need for better forest management contribute to increased wildfires throughout the western United State’s wine regions, research continues including an idea first developed for use on cherries that could be used to protect grapes from smoke as well. It is a phospholipid spray that forms a waxy layer on the grape skin and is food safe. Research and testing are ongoing to determine if the taste of the wine produced from the grapes is different.
“It’s been a steep learning curve for a lot of us in Monterey County,” Smith said, “but the positive in this is the sharing of information between neighbors and working with wineries to learn about it.”
