The oenological characteristics of commercial dry yeasts

Twenty preparations of dry active yeast (18 Saccharomyces cerevisiae and 2 Saccharomyces bayanus) available in Italy were tested in white and red musts (Moscato, Albana and Sangiovese) to study their oenological characteristics (i.e. fermentation rate, total alcohol and acetic acid production). After the application of chemometric techniques for descriptive analyses to the results of the oenological assessment, the yeasts were divided into 3 groups, A, B and C. Group A had some strains which caused low values of dry extract and glycerol in wines. Yeasts in group B were less interesting in terms of their oenological characteristics. Yeasts in group C had mixed behaviour with positive and negative characteristics and their utilisation must be considered separately each time. The research has shown that technological investigation is necessary after a correct selection of yeasts to limit the number of strains for subsequent study, and to characterize suitable strains for different oenological practices.