THE QUALITY OF RED WINE VRANEC, MERLOT AND FRANKOVKA FERMENTED BY COMMERCIAL AND BAKER’S YEASTS.

The aim of this study is determination of the quality of red wines from grape varieties Vranec, Merlot and Frankovka fermented by wine yeasts from the French manufacturer SELECTYS® LA DÉLICIEUSE and baker’s yeast seeded in a ratio of 0.25 g/L. The research was done during 2020 and 2021 in the Vinica vineyard, where the three grape varieties are grown at an altitude from 400 to 520 m. Regarding enological parameters, the highest amount of alcohol was measured for Merlot wines fermented by French yeast (13.07%), Frankovka wine fermented by baker’s yeast had the highest amount of sugar (9.71 g/L), Vranec wine produced by baker’s yeast had the highest total acidity (7.37 g/L) while the highest concentration of volatile acids was determined for Frankovka wine fermented by French yeast SELECTYS® LA DÉLICIEUSE (1.58 g/L). The impact of wine yeast to the quantity of particular elements was the most statistically significant for Fe57 in Merlot and Vranec wines, Cu65 in Frankovka wines and Pb208 in Merlot. Vranec and Merlot wines fermented by baker’s yeast indicated higher amounts of phenolic compounds while Frankovka wines produced by SELECTYS® LA DÉLICIEUSE showed opposite tendency with significantly higher amounts of polyphenols. [ABSTRACT FROM AUTHOR]