SUMMARY
The object of research is the starter culture used in the production of solid rennet cheese.One of the most problematic places is the selection of the number and composition of bacterial starter cultures for the production of hard cheeses with a low temperature of second heating.During the study, analysis and synthesis methods were used – when studying the sources of scientific literature on the research topic; laboratory methods (biochemical and microbiological) studies – when determining the optimal composition of bacterial starter cultures; organoleptic methods – in determining the quality of the finished product; methods of mathematical statistics – for processing research results.During the study, it was shown that in order to improve the coagulation of milk, which underwent high-temperature processing, it is necessary to add a double dose of calcium chloride and rennet and 0.1 % bacterial fermentation to the milk mixture. In addition, the mixture must be kept at 12 hours at 10–12 °C to improve the cheese ability of milk.As a research result, it is found that with an increase in the total amount of bacterial starter culture, there is an increase in the acidity of milk before coagulation, a decrease in the duration of mixing of the grain after the second heating, and an increase in the acidity of whey at all stages of the technological process.The most successful should be considered samples of cheeses made from sourdough, which included 1.5 % of the complex of mesophilic lactobacilli and 0.3 % of thermophilic lactobacilli Lb. acidophilus, the use of which ensures the formation of higher organoleptic characteristics of rennet cheese.The use of highly effective bacterial starter cultures, the increased moisture content in the product and the maturation of the product at elevated temperatures make it possible to obtain cheese with a reduced ripening time of 25–30 days.Thus, as a research result, optimal technological parameters are established that will allow to obtain rennet cheeses with a low temperature of the second heating of high quality.