Potassium Carbonate is used to lower acidity levels in wine. 3.8 grams per gallon will reduce acidity by about .1%. Potassium Carbonate requires that the fermenter be stored cold for several weeks after application (please see our guides to Cold Stabilization in the documents tab above). During the period of cold stabilization the tartaric acid drops out as potassium bitartrate. Doing a trial run with a small amount is strongly suggested to determine exactly what the drop in acidity will be. Calcium carbonate can be used in a similar manner and does not require cold stabilization. However it adversely affects flavor, takes month to precipitate out of solution, and preferentially reduces tartaric acid first before affecting malic or citric acid.
A rough approximate of weight is 1 tsp = 8.3 grams. We highly recommend using a scale to weigh the product for an accurate dose. We do not recommend relying on these rough conversions for accurate dosage rates.