In the study analyzed the use of soapstock generated during the alkaline refining of vegetable oils as a secondary raw material for the production of fatty carboxylic acids and their subsequent conversion into esters. In the study investigated the effect of acidulation conditions on the yield and chemical characteristics of fatty carboxylic acids obtained from soapstock under controlled temperature and residence time parameters. In the study revealed the relationship between acidulation conditions, phase separation efficiency, and changes in acid value and mass yield of fatty carboxylic acids. In the study studied the esterification process of soapstock-derived fatty carboxylic acids by varying reaction temperature, reactant molar ratio, and process duration. In the study determined the influence of esterification parameters on the degree of conversion of carboxyl groups and the yield of ester products. In the study established the dependence of acid value reduction on reaction conditions during the esterification of fatty carboxylic acids obtained from soapstock. In the study formed an experimental dataset describing the physicochemical properties of synthesized esters, including density and dynamic viscosity. In the study proposed a technological scheme for converting soapstock into esters through acidulation followed by esterification under controlled conditions. In the study presented a comprehensive experimental investigation covering fatty carboxylic acid recovery, ester synthesis, and physicochemical characterization of the resulting ester products.