Henry Kampen* and Benjamin Benitez
*California State University Fresno, 9 Edith Court, Napa, CA 94558 (hnkampen@gmail.com)

With increasing risk of wildfires in grapegrowing regions, the wine industry needs methods to remove or mask the unpleasant phenolic compounds present in smoke-tainted juice. The ability of yeast derivatives to mask or balance these undesirable wildfire volatile phenols (VPs; 4-ethylguaiacol, 4-ethyl phenol, guaiacol, and 4-methylguaiacol), especially on the retronasal mid-palate, was explored. These VPs contribute many negative sensory notes to wine, both aromatically and on the palate. We investigated the efficacy of two postfermentation yeast-derivative treatments in varying concentrations. Smoke-impacted Cabernet Sauvignon grapes were harvested from the Napa Valley AVA and processed using a standard winemaking regimen. Two experimental yeast-derivative treatments were compared at varying concentrations (50, 100, 250 and 500g/hL) to establish sensory masking effects. Regular bâtonnage was employed to ensure full contact with the yeast products. VPs were monitored by gas-chromatography mass spectrophotometry. Sensory analysis with a ranking test was used to determine if the levels could be differentiated from one another. The ability of yeast-derivative treatments in conjunction with amelioration methods to minimize the impact of wildfire smoke on future vintages will be established. The potential to mask or reduce the sensory impact of wildfire smoke could be beneficial to the wine production industry.

Funding Support: Laffort Labs