Influence of inactive yeasts on grape quality of cv. Plavina used in Prošek wine production

Wines from dried grapes have been produced for centuries in the Mediterranean. In Croatia Prošek is traditional dessert wine made form dried grapes. However, the traditional way of drying is increasingly neglected due to the inability to control conditions. Thus, the safest and fastest drying method is to use modern dryers. The aim of the study was to determine the dynamics of drying and changes in the quality of Plavina grapes in controlled conditions. The research was carried out at Baštica vineyard, where part of the grapes was treated with inactive yeasts (Lalvigne mature) at the beginning of vérasion, while non-treated grapes presented the control. The grapes were dried for 6 days in chambers at 40°C. After drying the mass of grapes decreased 25% in treated grapes and 35% in control. Significant difference was also observed in polyphenolic and volatile content of the treated grapes. The applied drying technology ensures the optimal health of the grapes, as well as production of new style of dessert wine and utilization of qualitative potential of Plavina cultivar.