Cream of tartar (potassium bitartrate) is commonly used as an ingredient in baking powder, or coupled with baking soda to activate the alkaline. It is also used in baking recipes for stabilizing egg whites (often used in meringues) and whipped cream as a thickening agent.

Despite its namesake, cream of tartar is actually an acidic by-product formed as a result of crystallization in wine making. It is sometimes used in sugar-based recipes to prevent crystallization.