Additives and Processing Aids

The standard of identity for wine in most wine-producing countries requires that wine be solely the product of complete or partial alcoholic fermentation of grapes, but also allows for additions of other materials to juice or wine. Materials used in winemaking must be explicitly allowed, that is, if a material is not expressly permitted for use in winemaking, then it is assumed to be forbidden. Some of these additions have been practiced for centuries or even millennia, as in the case of “plastering” a wine with gypsum (CaSO4) to lower wine pH, but others date to the last decade, and new additions are approved periodically. The function of most additives and processing aids fits into one of the following four categories: Antimicrobial; Stabilizing, clarifying, and purifying; Correcting natural deficiencies of the must or wine; and Yeast nutrients and microorganisms. The materials approved for use in each country are found in regulations associated with wine production.