The use of isolated wine yeasts in winemaking processes is preferable to spontaneous fermentation. Selection criteria of wine yeast strains depend also on capacity and rate of fermentation and on alcohologenic capabilities. Our studies have described the dynamics of fermentation of wine musts by some isolated wine yeast strains of Saccharomyces genus: strains 6 and 8 of S. cerevisiae var. ellipsoideus (S. ellipsoideus) and strains 5 and 7 of S. bayanus var. oviformis (S. oviformis). All have high technological properties and all are adapted for the specific pedoclimatic conditions of some areas of Sibiu viticultural region. The selected strains were used as inocula to ferment Sauvignon, Muscat Ottonel, Rose Traminer, and Pino Gris musts in controlled laboratory conditions. It was found that higher initial oxygen concentration in must is necessary to accelerate the fermentation of all the wine yeast strains studied. In order to obtain quality wines, strains with considerable fermentative capacity, high alcohologenic capabilities, and a good conversion efficiency are recommended.