This study is devoted to the isolation of biologically active substances of phenolic nature from the secondary raw materials of the wine industry, which are natural antioxidants. For the complete isolation of these valuable additives, the composition and yield of grape pomace were determined, which depends on the method of processing grapes, varietal characteristics and quality of pressing, as well as factors affecting it. The object of the study is the isolation of polyphenols from pomace of white and red grape varieties. The grape varieties Bayan-shirey and Madras grown in the conditions of Azerbaijan, as well as the pulp obtained from both varieties, were used as the material for the study. As a result of the study, it turned out that, depending on the technology used, the amount of unfermented "white" and fermented "red" pulp varied in different ways. It turned out that the seeds, skin and pulp have different characteristics in terms of chemical composition. Separate fermentation of pomace obtained from the grape varieties used in the study was carried out, and the average composition was determined. As a result of the analysis, the amount of phenolic compounds and polysaccharides in the studied pulp samples was determined. It was found that depending on the grape variety, the amount of nutrients in the flour obtained from the pulp varies widely. In the obtained extracts, the amount of biologically active substances (BAS) of phenolic nature was determined. The results of the analysis showed that reducing the amount of extractant in the water module to a certain extent increases the extraction of phenolic compounds. In this regard, the module 1 : 5 and 1 : 3 was the most optimal. It turned out that the extracts have a high antioxidant activity and, depending on the type of raw material, this indicator ranges from 1272.3 to 2545.3. The resulting additive can be used in the production of functional products.