Commercial source for tartaric acid extraction is

The commercial source of tartaric acid extraction is Grapes.
Tartaric acid is naturally found in grapes and bananas and has been reported to enhance the flavor of grape- and lime-flavored beverages.
Tartaric acid is a white, crystalline organic acid that occurs naturally in many fruits, most notably in grapes. Its salt, potassium bitartrate, commonly known as cream of tartar, develops naturally in the process of fermentation.