Potassium sorbate is used as a preservative in winemaking to prevent the growth of yeast and bacteria, which can cause spoilage and re-fermentation in wine. It works by inhibiting the yeast’s ability to reproduce and ferment, which helps to stabilize the wine and maintain its flavor and quality. Potassium sorbate is commonly used in conjunction with other wine stabilizing agents, such as sulfites, to provide a more comprehensive preservation solution for wine.