Other names: potassium acid tartrate, potassium bitartrate, cream of tarter (common misspelling)
Cream of tartar is a by-product of the wine industry. A crystalline acid forms on the inside of wine barrels. The barrels are scraped and the sediment is purified and ground to form cream of tartar. Cream of tartar is used to stabilize egg whites when making meringue or as an addition to certain frostings to produce a creamy product.