UC Davis

Smoke-derived volatile phenols can absorb into grapes, resulting in smoke-impacted grapes, decreasing the quality of the resulting wine by developing ‘smoke taint’ flavor. This study explored the interactive impact of deficit irrigation and mechanical fruit zone leaf removal on grape smoke exposure and the resulting wine composition. Our results indicate limited smoke impact only on the grapes, which did not result in smoke-tainted wines. This is mainly because the smoke that the vineyard was exposed to originated from 150 km away, resulting in lower density and aged (from 5 to 10 days after the fires started) smoke exposure only. The different irrigation treatments showed some effects on grapes’ volatile phenols but had little to no impact on wine composition. On the contrary, leaf removal showed larger effects on wines’ volatile phenols than the grapes’ volatile phenols, indicating that larger leaf area could provide some protections to grapes during smoke exposure.