Preferred method to lower acidity levels and raise pH in musts. 3.8 grams/gallon will reduce acidity by 1.0 gram/liter. Requires several weeks of cold stabilization for tartaric acid to drop out as potassium bitartrate. One teaspoon of the powder is approximately 6 grams.
An alternative method when there is need to lower acidity by greater than 2.0 g/l is to use calcium carbonate. Normal ranges for acidity levels in must/juice and wine are as follows:
Must/Juice g/L Finished Wine g/L
Dry White 7.0-9.0 5.0-7.5
Dry Red 6.0-8.0 4.0-5.5
Sweet White/Red 7.5-9.0 5.5-7.5
An acid test kit can be used to determine acidity of your must or wine.