While very common in citrus fruits, such as limes, Citric Acid is found only in very minute quantities in wine grapes.

It often has a concentration about 1/20 that of Tartaric Acid. Citric Acid is generally used by winemakers to boost a wine's total acidity.

It is used less frequently than Tartaric Acid and Malic Acid due to resulting aggressive citric flavors that it can add to the wine.

*** Add Citric Acid  after primary alcohol fermentation has been completed as yeast has a tendency to convert Citric Acid into Acetic Acid thus contributing a vinegary taste.