Transcription Profiling of Glycosyltransferases in Cultivars Following Smoke Exposure.

Smoke taint is a fault that can occur in wines made from smoke-affected grapes. Smoke taint research has largely focused on chemical and sensory analysis and mitigation strategies, with limited attention to underlying molecular responses. We performed RNA sequencing on berries from cultivars Shiraz and Chardonnay after controlled smoke exposure.

Accumulation of volatile phenol glycoconjugates in grapes following grapevine exposure to smoke and potential mitigation of smoke taint by foliar application of kaolin.

The accumulation of volatile phenol glycoconjugates in smoke-exposed grapes was monitored following grapevine exposure to smoke, with different glycoconjugate profiles observed for fruit sampled 1 and 7 days after smoke exposure, and at maturity. Foliar application of kaolin reduced the concentration of volatile phenol glycoconjugates in smoke-exposed fruit, but efficacy depended on the rate of application and extent of coverage. Smoke taint can be found in wines made from grapes exposed to smoke from bushfires or prescribed burns.

Impact of Bottle Aging on Smoke-Tainted Wines from Different Grape Cultivars.

Smoke taint is the term given to the objectionable smoky, medicinal, and ashy characters that can be exhibited in wines following vineyard exposure to bushfire smoke. This study sought to investigate the stability of smoke taint by determining changes in the composition and sensory properties of wines following 5 to 6 years of bottle aging. Small increases in guaiacol and 4-methylguaiacol (of up to 6 μg/L) were observed after bottle aging of smoke-affected red and white wines, while syringol increased by as much as 29 μg/L.