Nicolas Delchier and Andrew L. Waterhouse*
*UC Davis, 595 Hilgard Lane, Davis, CA 95616 (alwaterhouse@ucdavis.edu)

Higher alcohols and esters are produced during wine Higher alcohols and esters are produced during wine fermentations. These compounds are fundamental to wine aroma. Some studies have shown that they could also be involved in headaches that occur after wine consumption. Our study aimed to determine the evolution of esters and higher alcohols during red and white wine fermentations. Red fermentations from Cabernet Sauvignon grapes, were carried out at room temperature with three different yeast strains: BM45, EC 1118, and ICVD 254. Initial Brix was 20, 22, 24, and 26 for strain BM45, while an initial Brix of 26 was used for both EC1118 and ICVD 254. White fermentations were carried out at room temperature from Chardonnay juice. BM45, Rhone 2056, and Rhone 2226 yeast strains were used, with initial Brix of 20, 23, and 26. Esters and higher alcohols were quantified by GC-MS during fermentation. Samples were centrifuged for 10 min at 5000 rpm, filtered through a 0.45µm PTFE, and then analyzed. Five compounds were observed to evolve significantly during fermentation of both white and red wines: 2-methyl-1-propanol, 1-propanol, 2 methyl-1-butanol, phenyl ethyl alcohol, and ethyl acetate. For all the compounds, concentrations increased initially during the fermentation and then reached a plateau before fermentation was complete. The highest concentrations were noted for 2-methyl-1-butanol in both the red and white fermentations, while the lowest levels were observed for 2-methyl-1-propanol in the red wines and ethyl acetate, in the whites. The initial sugar concentration correlated with the concentrations of only 1-propanol and ethyl acetate. In addition, yeast strain had an impact on the production of higher alcohols and esters.

Funding Support: UC Davis