The USDA Ag Research Service is helping grape growers and winemakers save wine grapes impacted by wildfires by finding a natural solution to remove the unpleasant flavors caused by smoke taint — which costs billions of dollars in the U.S. wine industry.
Smoke taint occurs when wine grapes are exposed to high levels of smoke in a vineyard and absorb volatile compounds. The leaves and grapes attach sugars to the smoke compounds and store them, which results in unpleasant flavors in the wine, often described as tasting “smoky” or “ashy.” Consequently, most grapes exposed to wildfire smoke are considered unsuitable for making wine.
In a research study, researchers from the ARS Plant Gene Expression Center in Albany, CA, and their collaborators found that Gordonia alkanivorans, a bacterium that can occur naturally on grape leaves, is able to break down guaiacol, one of the main phenols responsible for smoke taint in wine. Phenols are naturally occurring chemical compounds that are responsible for much of the flavor and color in wine.
“We found two strains of the same species of Gordonia alkanivorans that can use guaiacol as their only food source,” said Devin Coleman-Derr, ARS Research Molecular Biologist.
The researchers sequenced the strains’ genomes and studied which genes were active when Gordonia alkanivorans were given access to guaiacol. They found that a gene called guaA produced an enzyme that was key to breaking down guaiacol into a harmless compound. Furthermore, the guaAenzyme broke down only guaiacol and not the other phenols.
Though guaiacol is just one of several phenols potentially responsible for smoke taint,Coleman-Derr says the findings show that using bacteria as a biotechnological tool in treating smoke taint is a potential solution.
“This research provides a roadmap for finding bacteria and other microbes that can target other problematic chemicals in or on plants,” said Coleman-Derr.
The research was done in collaboration with University of California, Merced’s Department of Molecular and Cell Biology, Oak Ridge National Laboratory’s Biosciences Division, and Washington State University’s Viticulture and Enology Program. – By Jessica Ryan, ARS Office of Communications
The U.S. Department of Agriculture (USDA) has released additional details on a new crop insurance endorsement to better protect California wine grape growers from the devastating impacts of wildfire smoke. The Fire Insurance Protection-Smoke Index (FIP-SI) endorsement, developed by USDA’s Risk Management Agency (RMA) in collaboration with industry stakeholders, including the California Association of Winegrape Growers (CAWG), is set to be available as a pilot program for the 2025 crop year.
FIP-SI will be available to grape growers in all California counties, with the deadline to sign up for coverage being January 31, 2025.
The endorsement is designed to provide grape growers with an additional layer of financial protection in the event of significant smoke exposure. This area-wide policy triggers a loss when a minimum number of cumulative Smoke Events occur during the insurance period, as defined in the policy using data from the National Oceanic and Atmospheric Administration’s (NOAA) Hazard Mapping System Smoke Product.
“The 2020 wildfires sent shockwaves through the wine industry, with losses from smoke-exposed fruit felt throughout the state. Since that devastating year, we’ve been working diligently to find solutions to better safeguard California’s winegrape growers from the impacts of wildfire smoke,” said Natalie Collins, CAWG President. “The introduction of this targeted risk management tool for smoke marks a significant step forward in protecting the livelihoods of our growers and the future of the wine industry as we continue to face the challenges posed by increased wildfire activity.”
Collins continued, “CAWG extends its gratitude to RMA’s Product Development Team for their extensive work in crafting and introducing this critical crop insurance endorsement. We also commend U.S. Senator Alex Padilla and Congressman Mike Thompson for their advocacy in calling for action through crop insurance to better protect the CA wine industry.”
CAWG will host an educational webinar on Thursday, November 14 at 10:00am, where Relation Insurance Services will present in-depth information on the new FIP-SI endorsement. The webinar will discuss how FIP- SI interacts with growers’ existing policies, and answer any questions from growers.
About the California Association of Winegrape Growers (CAWG)
CAWG is a statewide nonprofit trade association advocating for California’s winegrape growers to ensure the sustainability of the winegrape industry. CAWG promotes the industry’s long-term success by advancing the adoption of sound public policies and fostering awareness and understanding of winegrape growers’ contributions to the economy, environment, and California communities. Learn more at cawg.org.
Viticulture and enology researchers from multiple universities have been feverishly working with the western wine grape industry to learn more about how wildfire smoke impacts developing wine grapes. The hope is to develop some form of industry standard threshold for smoke taint, so that wine grapes will not be rejected at the winery unless they have truly been compromised. Watch this brief video with Miguel Pedroza from the Viticulture & Enology Dept. at Fresno State to find what they are learning about this issue. Read more about it in American Vineyard Magazine.
Please thank this video’s sponsor Suterra for their industry support.
Where there’s drought, there’s fire, and where there’s fire, there’s smoke. This is a major concern for wine grape growers in the drought-stricken west this year. Evacuations, power outages and smoke taint have had a major impact on the wine industry at harvest-time in recent years, and not having an industry standard or threshold defining smoke taint can raise questions and contention upon delivery at the winery. Watch this brief video with John Aguirre from the California Association of Winegrape Growers as he shares the progress on the West Coast Smoke Exposure Task Force in the investigation of smoke taint. Read more about it in American Vineyard Magazine.
Please thank this video’s sponsor Suterra for their industry support.
Smoke taint is unfortunately an annual concern now for wine grape growers, and this was a topic of interest at the recent Sonoma Grape Expo. Watch this brief video with UCCE Specialist Anita Oberholster as she shares what’s been learned so far about the issue and how growers can prepare their operations as they head into another dry wildfire threatening season. Read more about it in American Vineyard Magazine.
Please thank this video’s sponsor Suterra for their industry support.
Smoke taint has dominated the worries of the California wine industry recent years. With unsettled climate conditions and continued droughts, there is no reason to think that smoke taint will not continue to be a significant concern for the foreseeable future. In 2017 and 2020, California growers and wineries both had to scramble to adapt as they found that existing science, customs and contractual arrangements left them ill-prepared to deal with the smoke taint challenge. Avoiding a similar situation once smoke taint inevitably strikes again means understanding the problem and having a strategy in place to address it.
What is smoke taint?
Drinking smoke-tainted wine has been compared to tasting a campfire or an ashtray: most would agree that these are not desirable attributes for wine. These off flavors are caused by volatile phenols that are released by plant matter when it burns. The volatile phenols bond with sugars in the grapes, which produces glycosides. Unlike volatile phenols, glycosides are not volatile, so the smoky quality cannot be smelled or tasted.
The Problem of Uncertainty
During a typical crush, grapes are harvested in the field, delivered to the winery crush pad, inspected, accepted if there are no obvious signs of defects, and the fermentation process begins. If the winery buys the grapes from a grower, acceptance typically obligates the winery to pay the grower, with payment due shortly after harvest, or in installments, the first shortly after harvest and the second a few months later.
However, one of the biggest challenges of smoke taint is its latency. In effect, volatile phenols hibernate: Glycosides become volatile as the wine is fermented and aged and smoke can then be smelled and tasted. It is hard to predict when this will occur, making it difficult to detect, plan for and mitigate the risk of smoke taint during the usual wine making process.
Compounding the uncertainty, there is no universally accepted definition of smoke taint in the industry. Different laboratories and wineries rely on different levels of different chemical markers. Relying on taste and smell is inherently subjective, painfully obvious in some cases, subtle and hard to discern by some palates in others.
Contract Approaches
Ultimately, uncertainty breeds trust and relationship issues best solved in the grape purchase contract. Parties negotiating grape contracts should consider:
Identifying smoke taint using specific chemical markers (perhaps periodically revisited in good faith during the contract as industry knowledge evolves) or using truly neutral subjective evaluators
Using tiered pricing depending on the levels of chemical markers found
Incorporating processes that recognize smoke taint’s latency by delaying acceptance of suspect grapes
Allowing suspect grapes to be processed for the grower’s account
Including a holdback of some portion of the purchase price
Some combination of the above
Don’t Overlook Insurance
Growers and winemakers should review their insurance policies in detail before and after smoke taint strikes and consider working closely with a broker or lawyer to determine whether, when, and how to make a claim.
Understanding how insurance works with smoke taint now can help prepare you after smoke taint strikes. One of the trickiest issues is determining which insurance policy will cover a potential loss. As a general matter, crop insurance will cover damage to grapes while they are on the vine while other forms of property insurance will cover “damage” to grapes after they have been harvested. Growers with healthy crop policies should encourage field inspections before harvest to enable timely claims.
However, since it may not be clear when the grapes were “damaged,” steps taken under one type of policy could impact a claim under a different type of policy. If it is not clear when the grapes were damaged, potential claimants should review their policies carefully and work closely with their consultants, lawyers and brokers to determine the best approach to a potential loss.
Taking the time now to understand your policies before smoke taint hits can help make the claim process less stressful and ensure that no important steps are missed. Grape growers and winemakers should review their insurance policies to determine the supporting documentation required to file a claim. Some policies, for example, may require information about when the grapes were affected, where they were affected, and for how long.
Many policies will also require lab tests from preapproved labs that indicate the presence of smoke taint. At present, pre-harvest tests typically focus on the presence of guaiacol and 4-methylguaiacol and are performed either on whole berry clusters or after the micro-fermentation of samples. Although post-fermentation tests can help confirm the presence of smoke taint, many policies will still require pre-harvest test results.
Potential claimants should also look for other requirements that might affect the viability of their claim. Does a policy require winemakers to segregate the juice from different lots, and should this be part of grape contract negotiations?
Carefully reviewing insurance policies and closely working with your consultants, insurance broker and lawyer may also uncover unexpected sources of recovery. For example, if crop insurance is not available or does not fully cover the loss, it might still be possible to obtain coverage for lost profits and extra expenses due to grower’s inability to harvest grapes due to lack of access or other reasons, or a winery’s inability to procure the grapes it needs to produce wine. As always, to maximize insurance recoveries, it is necessary to quickly and thoroughly gather all relevant facts, supporting documentation and relevant insurance policies, and understand (with a professional’s help, if required) how the insurance policies might respond to particular losses before deciding how one or more insurance claims should be pursued.
Next Steps
Potentially ruined grapes are bad enough: the inherent uncertainty around smoke taint’s presence, cause, and extent exacerbates the related contract and insurance problems. To reduce this uncertainty: review insurance policies and grape contracts so you understand their terms, consider negotiating grape contracts to incorporate practical procedures, and reach out to your consultants, insurance broker or lawyer with any questions about contracts, policies, or general strategy for addressing potential smoke taint damage. Anything you do now can reduce the pressures of the next fire season. – By Matthew Lewis, Tyler Gerking & MaryJo Lopez
Matthew Lewis (right) is a business transactions partner, Tyler Gerking (left) is an insurance recovery partner, and MaryJo Lopez (middle) is an business litigation associate in Farella Braun + Martel’s Wine Industry Group. They can be reached at mlewis@fbm.com, tgerking@fbm.com, and mlopez@fbm.com.
Growers across California are now accepting the fact that wildfires are a seasonal threat to their crops. With wineries rejecting “smoke tainted” wine grapes even under contract, this has become a very sensitive issue, particularly in Northern California, Oregon and Washington. But just how much smoke exposure to the crop warrants rejection as being “smoke tainted?” Working with local wine grower organizations, UCCE Viticulture Farm Advisor Glenn McGourty set out to determine the truth. He shared results of this study recently at Malcolm Media’s Sonoma Grape Expo. Watch this brief interview as Glenn as he shares the results of his study and read more about it in the coming issue of American Vineyard Magazine.
Please thank our sponsor Duarte Nursery for their industry support and see them at their booth at Unified Wine & Grape Symposium in Sacramento, February 4-6 (Booth P1842).
Over the last few years, many western wine grape growers have had issues around harvest with wildfires, and some have even had their grapes rejected by the wineries due to the smoke exposure from these relentless fires. Many of these growers were even under contract. This regular wildfire pattern does not appear to be changing anytime soon, and there is very limited information on smoke taint in grapes, and at what point a crop merits rejection. That is why the industry has received some funding to conduct more research in this field of study and previously impacted growers now have the opportunity to recoup some of their losses through the USDA Farm Service Agency. Watch this interview with John Aguirre, President of the California Association of Winegrape Growers as he explains and read more in the September issue of American Vineyard Magazine.
Please thank our sponsor Duarte Nursery for their industry support and attend their upcoming Grapevine Clonal Field Days. Learn more HERE.
The American Vineyard Foundation (AVF) is pleased to announce new funding for twenty-four projects addressing critical viticulture and enology research needs. The AVF relies on voluntary contributions to support ongoing projects and to provide funding for new high priority projects. “Thanks to the generosity of nearly one-thousand grower and vintner members, the AVF continues to drive research solutions to the challenges we face in our vineyards and wineries,” remarked AVF Chairman Tony Stephen.
The AVF received 68 proposals for grant consideration covering topics diverse as “Exploring Wine Protocols to Mitigate Smoke Taint” and “Evaluating Fine Root Response to Drought” to “Next Generation Trunk Disease Diagnostics.” Each proposal was evaluated by one of the six AVF review committees for scientific merit, the ability to accomplish stated objectives and to deliver value to the industry.
AVF members are surveyed on a periodic basis to determine which issues are in most need of research. “We encourage broad participation when we conduct our 2018 Industry Research Priority Survey later this year,” AVF Manager Scott Deitrick emphasized. “This is your opportunity to identify and rank your top research priorities to help guide AVF project funding going forward.”
To view the full list of 2018 funded projects and browse prior research summaries, please visit www.avf.org
About the American Vineyard Foundation – The American Vineyard Foundation (AVF) is a California corporation organized in 1978 by the American Society of Enology and Viticulture as a vehicle to raise funds for research in viticulture and enology. Basic and applied research has made the American grape and wine industry the world’s leader. The AVF provides a unique opportunity to unify the industry through an industry-wide research effort to maintain this progress. For more information visit www.avf.org
The American Vineyard Foundation (AVF) is pleased to announce new funding for twenty-four projects addressing critical viticulture and enology research needs. The AVF relies on voluntary contributions to support ongoing projects and to provide funding for new high priority projects. “Thanks to the generosity of nearly one-thousand grower and vintner members, the AVF continues to drive research solutions to the challenges we face in our vineyards and wineries,” remarked AVF Chairman Tony Stephen.
The AVF received 68 proposals for grant consideration covering topics diverse as “Exploring Wine Protocols to Mitigate Smoke Taint” and “Evaluating Fine Root Response to Drought” to “Next Generation Trunk Disease Diagnostics.” Each proposal was evaluated by one of the six AVF review committees for scientific merit, the ability to accomplish stated objectives and to deliver value to the industry.