Mitigating agricultural losses from wine grape exposure to wildfire smoke by distillation and barrel maturation: Sensory and chemical profiles of brandy spirit made from smoke tainted grapes.

Abstract

Rising global temperatures and altered rainfall patterns are increasing the risk of wildfires that pose viticultural challenges due to grape contamination by smoke containing volatile phenols (VPs). VPs permeate grape pericarp, producing an unpalatable "smoke taint" in resulting wines. Tainted wines from three varieties (Sauvignon Blanc, Shiraz, and Pinot Noir) were double distilled and the spirit matured using two different oak treatments. Chemical analysis by GC-MS, hedonic evaluation, and sensory profiling by rate-all-that-apply were undertaken. The "heart" fractions from double distillation had low levels of VPs, and matured spirit typically showed a greater oak influence in contrast to wildfire derived VPs. Sensory analysis confirmed that double distillation decreased the aroma impact of smoke derived VPs and encouragingly, preference was subsequently improved by oak maturation of the produced spirit. Consumers are likely to accept oaked brandies produced from smoke tainted wine, thereby providing a viable commercial use of wildfire affected grapes.