The increasing incidences of wildfires in winegrape growing regions pose a significant risk to the grape and wine industry. One risk is the potential for persistent exposure to smoke to compromise the quality and value of winegrapes and adversely affect wines made from smoke exposed grapes. A wine is seen as smoke impacted or tainted when there is an overpowering smoky, medicinal, chemical, burnt or ashy aroma on the nose and a distinctive retronasal ash tray-like character in the mouth. Several solutions for smoke taint have been promoted such as treatment with enzymatic enzymes, fining, reverse-osmosis and spinning cone treatments. In this study the different amelioration techniques were investigated using smoke impacted wines made from Cabernet Sauvignon grapes from Napa and Lake Counties (UC Davis Teaching and Research Winery) in 2017 and 2018. The impact on wine composition, specifically smoke taint marker compounds (both free and bound volatile phenols as determined by GC-MS/MS and LC-MS/MS) as well as other key volatile and non-volatile compounds important for wine quality were evaluated to determine its effectiveness. Results indicated that although most amelioration techniques removed some smoke taint markers (both free and bound) and decreased smoke taint perception, it lacked specificity and impacted the overall attributes of the wine, in a negative way. However, the impact depended on the level of treatment needed and the decrease in mouthfeel could be adjusted using TTB approved products or blending. In conclusion, amelioration techniques are not 100% fixes of smoke taint but can significantly decrease smoke taint perception and with further research recommendation can potentially be made to the feasibility of treatment success based on the wine matrix so that winemakers can make informed decisions.

Impact of different amelioration techniques on the chemical composition and sensory characteristics of smoke impacted wines

ACS Fall 2020 Virtual Meeting

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