Non-Irradiated Kosher Cream of tartar powder (potassium hydrogen tartrate) or tartaric acid, is an effervescent acid obtained as a by-product of wine making. The acidic powder is used for culinary and other household purposes, among them: stabilizing egg whites and increasing their heat tolerance; preventing sugar syrups from crystallizing; reducing discoloration of boiled vegetables. Cream of tartar is widely distributed by nature in many fruits, but is usually obtained as a by-product of wine making. During the fermentation of the grapes, tartar crystallizes in the wine casks. The crystals are collected and purified to produce the white, odorless, acidic powder.Frontier Natural Products