Optimization of Plum Wine Brewing Process and Effects of Different Clarifying Agents on Its Quality and Stability

Traditional plum wine brewing mostly relies on experience, with problems such as lack of standardized production parameters and easy formation of sediment after fermentation. This study systematically optimized the key production processes. Based on the results of a single-factor experiment, the Box–Behnken design of the response surface method (RSM) was employed to determine the optimal fermentation parameters, which included a fermentation temperature of 31 °C, fermentation duration of 12 days, yeast inoculation rate of 0.86%, initial pH of 3.5, and sugar content of 28.5%. Under these conditions, the alcohol content reached 13.7%vol. On this basis, emphasis was placed on evaluating the effects of various clarification techniques (clarifying agents, heat treatment, membrane filtration, static clarification at different temperatures) on optimized base wine clarity, stability and quality. The results showed that chitosan exhibited excellent overall performance, not only obtaining the highest light transmittance (89.8%) but also the best effect in enhancing the iron stability (88.6%) and oxidative stability (88.9%) of the wine. Additionally, while membrane filtration, heat treatment, and freezing treatment all served to clarify and stabilize the wine, they significantly reduced the polyphenol content, thereby diminishing the wine’s quality. Therefore, the clarification process needs to be selected in practical production by considering the clarification effect and functional ingredient retention in conjunction with the production cost. This study provides key process parameters for the production of high-quality plum wine and theoretical guidance for reductions in sediment formation.