Fermented milk products are one of the most common foods among the population. This category of products includes yogurt, which is available in its various variations: with different acidity concentrations, with various additives, and different fat content. The article presents the results of studies on the influence of a complex of microorganisms on the quality indicators of yogurt (organoleptic, physicochemical). The purpose of the research was to study the effect of different volumes of symbiotic starter on the quality indicators of yogurt. The research was carried out in the laboratory of the Department of Biotechnology and Food Products of the Ural State Agrarian University.The Methods. Four yogurt samples were produced and analyzed: a control sample and three experimental ones. The finished products were assessed for organoleptic characteristics and mass fraction of protein (GOST 31981-2013). Acidity was set according to GOST 31976-2012.The Results. According to experts, sample No. 2 was recognized as the best, with a total volume of the complex of microorganisms of 70 ml per 150 g of the finished product. This sample had a uniform consistency, undisturbed clot, and no whey separation was observed; taste and smell – pure, fermented milk; color – milky white. All test samples had deviations in the protein mass fraction. Thus, in sample No. 1, MDB was 3.4%, in samples No. 2 and No. 3 – 3.6 and 3.8%. The obtained indicators were higher than the standard values by 0.2, 0.4 and 0.6%, respectively. Acidity in all samples was within normal limits.The Conclusion. Yogurt, with a complex of microorganisms can expand the line of functional products, and the addition of symbiotic starters will improve the properties of the product and classify it as functional.