How is deacidification achieved?

• A. Adding calcium carbonate (chalk) or potassium carbonate
• B. Aging on lees
• C. Filtration
• D. Adding malic acid

Answer: (A)

Deacidification works by neutralizing some of the wine’s acids with an alkali. The standard approach is to add calcium carbonate (chalk) or potassium carbonate. These bases react with tartaric acid to form calcium tartrate or potassium tartrate, which then precipitates out of the wine. With less acid in solution, the wine’s acidity decreases and the pH rises slightly, resulting in a smoother taste. Aging on lees changes texture and aroma but doesn’t remove acidity. Filtration clarifies without significantly changing acidity. Adding malic acid would increase, not decrease, acidity. (Malolactic fermentation is another way to soften acidity by converting malic to lactic acid, but that method isn’t what’s listed here.)