Calcium carbonate (CaCO3) increases pH to help reduce acidity in wine. Also known as chalk or powdered chalk.
CaCO3 is not an effective brewing water addition since it does not dissolve readily in water, but is effective in neutralizing acidity in an already acidic environment.
Dosage: 2.5 grams/gallon will lower acidity by approximately 0.1%. Reduces tartaric acid before malic and citric acids. Affects the flavor of the finished wine.