Before you add, check the acid level with pH Strips or an Acid test kit. Readings taken using pH strips should be about 3.8 to 3.4.
One level teaspoon of Citric Acid will raise the acid content of one U.S. gallon by .15% - Tartaric. Product of U.S.
Citric Acid is the primary acid found in fruits such as oranges, lemons, and pineapples. It is typically used in wines that are naturally lacking in acid.