Anne Flesch and Etienne Dorignac*
*Fermentis, 137 rue Gabriel Peri, 59170 Marcq-en-baroeul, France (e.dorignac@fermentis.lesaffre.com)

Consumer preferences are trending toward fresher and more expressive wines, combined with greater attention to the environment and to their health. This work offers “blending” tools for winemakers to help them produce intensely fruity and clean wines. Yeast hybridization was followed by a multi-step screening of the strains. It first focused on fermentation ability and sulfite production, then on acetaldehyde and acetate esters, and finally on tasting properties. A specific hybrid produced an aver- age 40% less acetaldehyde and sulfites and two to four times more isoamyl acetate than reference strains. This latter compound imparted distinctive candy flavors and was a strong flavor enhancer, making this strain a powerful tool for blends by enhancing fruitiness and decreasing sulfite concentrations of base wines. Enhancing flavors and improving fermentation by using different species of yeast strains may also represent a solution. In a second work, we focused on the impact of a species not known in wine: Saccharomyces pastorianus. Fermentations were conducted on a Sauvignon blanc must using single strains (two different S. pastorianus, one S. bayanus, and two different S. cerevisiae) and mixtures of them (S. pastorianus 1 or 2 and S. bayanus) and two different inoculation temperatures: cold (13°C) and classic (17°C). Both S. pastorianus strains achieved fermentation, produced almost no acetic acid, and overproduced 2-phenylethanol and its acetate. S. pastorianus 2 was of particular interest thanks to its nice tropical fruit notes. Considering its enological properties, S. pastorianus species may be of interest for winemaking, alone or in co-inoculation with S. bayanus and, in particular, to help decrease wine volatile acidity.

Funding Support: Lesaffre-Fermentis