Differences between wines fermented with and without sulphur dioxide using various selected yeasts

Comparisons were made between wines resulting from the fermentation of a single grape must of the Verdejo cultivar with various yeasts, namely the indigenous must microflora, pure cultures of Kloeckera apiculata, Torulaspora delbrueckii and Saccharomyces cerevisiae, and mixtures of these cultures, all with or without the addition of SO2. There were major differences in both volatile and non‐volatile compounds. Principal component analysis and cluster analysis showed that these differences were due mainly to the effects of the sulphur dioxide upon the yeasts. Analytical data on the wines demonstrate that the nature of a wine depends upon the particular yeasts present during the fermentation in the absence of SO2. On the other hand, if the fermentation is carried out in presence of SO2, similar wines are produced despite differences in the microflora.