A tartaric acid reducer to be used after fermentation.
Usage: 1 1/2 teaspoon per gallon of wine will reduce acidity approximately 0.1 %. Do not reduce more than .3-.4 %.

Potassium Bicarbonate is used in wine to help lower the acidity. 3.4 grams per gallon will effectively reduce acidity by 0.1%. You do not want to reduce the acidity by more than 0.3 – 0.4%.