Analysis of Sensory-Active Volatile Phenols in Smoke-Exposed Grapes by Gas Chromatography (TN-2068)

Volatile phenolic compounds are expressed endogenously in wine grapes and have been shown to increase following on-vine smoke exposure due to forest fire. Depending on their relative concentrations (among other factors) VPs can possess negative organoleptic properties, with sensory descriptors such as ‘ashtray’ and ‘Band-aid’ often associated with wines made using smoke-exposed grapes. The evaluation of smoke exposure is a significant quality control issue for vineyards, but also for wineries, as the concentration of VPs may increase during fermentation or aging. With climate models predicting an increase in the frequency of forest/brush fires and the localization of many key wine producing regions near or in areas prone to such fires (e.g., California, British Columbia, Australia, South Africa), it is critical to expand our current understanding of this economically important phenomenon.