Cream of Tartar is a mild, acid - potassium acid tartrate, or potassiumbitartrate. It is the product left after cold storage of new wine and issometimes referred to as wine-makers sand. Cream of Tartar prevents sugar crystallization in syrups. Cream of Tartardoes not get old. If using to stabilize egg whites & whites wont beat, it is not due to ageof Cream of Tartar. Failure of egg whites to beat may be because eggs aretoo old, humidity, grease in the bowl or on the beater, a speck of yolkin the whites, or the mixture may have been allowed to sit too long. Cream of Tartar has a slightly acidic, sour flavor. INGREDIENTS: cream of tartar