A commercial wine stabilizer that should be used in conjunction with Campden or its active ingredient, potassium metabisulfite. In other words, it works better with sulfites present than without, and it works better than sulfites alone. Potassium sorbate disrupts the reproductive cycle of yeast. Yeasts present are unable to reproduce and their population slowly diminishes through attrition.
Potassium sorbate is added in the amount of 1/2 teaspoon per gallon of wine. Sorbic acid results and stabilizes the wine. Usually the crushed Campden and potassium sorbate are dissolved in a cup or two of the wine to be stabilized and stirred thoroughly. Allow the stirred wine to sit a few moments and look for small white lumps of undissolved powder. If present, continue stirring until the wine is clear without any undissolved lumps. This is then added to the larger batch and stirred in well.