The authors proposed a milk-containing product with a substitute for milk fat, produced according to the technology of sour cream using a protective culture in order to prolong the shelf life. The use of protective starter cultures does not require additional equipment or changes in technological parameters. The protective culture is introduced along with the main sourdough and works according to the traditional principle of fermentation, as well as through competitive exclusion, i.e. taking up space and reducing the possibility for the growth of yeast, molds and BGKP. Two developments of a milk-containing product were carried out - the first using a protective culture (experimental sample), the second without using a protective culture (control sample). The products are stored for 40 days at a temperature of 4 ± 2 °C. In the control sample, on day 30, yeast growth, deterioration in organoleptic indices, increase in titratable acidity were observed, on day 40, the product was considered spoiled. In the experimental sample, organoleptic, physicochemical and microbiological parameters during storage were within normal limits. The shelf life of a milk-containing product with a milk fat substitute produced using the technology of sour cream is determined using a protective culture taking into account a safety factor of 30 days. An increase in the shelf life of the latter by 30% was established in comparison with the control sample.