SPECIFIC FEATURES OF FERMENTATION OF THE MUST FROM WHITE GRAPE VARIETIES IN THE CONDITIONS OF THE ODESSA REGION

Abstract

One of the most important problems of the modern wine technology is the production of high quality and competitive products. It is commonly known that the quality of a wine largely depends on the yeast race. The main requirement for yeast is completeness of fermentation, which depends on the amount of yeast involved, aeration, initial content of various substances in the must, temperature, pH of the environment. Using imported materials in the specific conditions of national winemaking requires laboratory and industrial research to rationalize the use of local and foreign pure yeast cultures and to accelerate the process of grape must fermentation. So, this study considers how the yeast origin and additional nutrition effect on grape must fermentation and influence the physicochemical and organoleptic characteristics of wine materials obtained from the white grape varieties Aromatny and Zagrei of the generative breeding by the National Scientific Centre Tairov Viticulture and Winemaking Institute. Besides, it has been concluded whether using additional nutrition is practical. It has been established that the fermentation process was complete in both the control and the experimental samples. There were no facts of underfermentation. When supplementary nitrogenous nutrition was used, the fermentation activity of yeast increased and the fermentation process ended faster. The dynamics of the total number of cells of the Aromatic and Zagrei varieties was the same during the years 2015–2017 and did not depend on the fermentation scheme. It has been found that the fermentation process does not depend on supplementary nutrition, but the yeast race effects on the physicochemical parameters, namely on the volatile acids content. The results obtained have shown the effect of a yeast race and supplementary nutrition on the organoleptic characteristics of these varieties. In Southern Ukraine, to control the quality characteristics of wine materials, using active dry yeast Saccharomyces cerevisiae with a two-stage nutrition complex has a positive effect on the physicochemical parameters of the corresponding grape variety and allows revealing its varietal characteristics.