Wildfires are an escalating threat to vineyards worldwide, particularly in regions like the West Coast of the U.S. Beyond physical damage, smoke exposure of grapes introduces volatile compounds into grape skins, which can result in wines with undesirable smoky, burnt, and ashy flavors. These off-flavors can mask fruit and floral notes, reducing wine quality and consumer appeal. With wildfire frequency projected to rise, winemakers need practical strategies to manage smoke taint during production.
One potential winemaking strategy to mitigate the smoke exposure impact, is the use of oak during wine production to modify the wines sensory profile. Anecdotally, winemakers have reported variable success with this approach, but there is limited research to confirm this observation. A case study was therefore conducted to examine how oak usage influenced the sensory profile of smoke-affected Cabernet Sauvignon. Researchers analyzed eight commercially-produced wines from three smoke-impacted vintages, focusing on three key questions:
1. Does oak origin (French vs. American) alter smoke flavor perception?
2. Can oak chips and carbon fining improve sensory quality?
3. Is there flavor carryover when reusing barrels that previously held smoke-affected wine?
Trained sensory panelists evaluated wines for seven attributes, including smoky, ashy aftertaste, floral, and fruit notes. Statistical analyses compared treatments to identify significant differences.
Oak origin matters. Wines aged in American oak exhibited significantly lower smoky and ashy intensities than those aged in French oak. American oak imparts higher levels of aromatics, which can mask harsh smoke flavors and enhance complexity. Carbon fining slightly improved floral notes but did not significantly reduce smoke flavors at the tested dose. Oak chips alone—and in combination with carbon—failed to improve the sensory profile and sometimes reinforced ashy notes. This suggests that combining treatments should be approached with caution, as oak chips can introduce phenols similar to smoke compounds. No barrel carryover between years was found. Wines aged in barrels that previously held smoke-affected wine did not exhibit additional smoke flavors, alleviating concerns about reusing barrels.
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These findings provide actionable guidance for wineries facing smoke-tainted grapes. By tailoring oak use and treatment strategies, producers can improve wine quality and reduce economic losses in smoke-impacted years. As wildfire risk grows, this research empowers the industry to adapt with informed, sensory-driven decisions rather than costly trial-and-error approaches.
Further research is needed to confirm these effects across different varietals, smoke exposure levels, vintages and consumer preferences. However, this study offers a foundation for practical decision-making in the cellar. For wineries navigating the challenges of smoke taint, oak management is not just tradition—it’s a tool for resilience. — By Dr. Elizabeth Tomasino, Professor of Enology & Dr. Jenna A. Fryer, Department of Food Science & Technology, Oregon State University, Corvallis, OR.
This project was funded by Specialty Crop Research Initiative Grant #2021-51181-35862/project accession #1027470 from the USDA National Institute of Food and Agriculture and USDA-Agricultural Research Service (ARS) project number 2072-21000-057-00D. Any opinions, findings, conclusions, or recommendations expressed in this publication are those of the author(s) and should not be construed to represent any official USDA or U.S. Government determination or policy.