Cream of tartar is a white powder found in the baking aisle that is commonly used to help stabilize whipped egg whites in meringues and cakes and give snickerdoodle cookies their signature flavor and texture. It’s made from tartaric acid, a byproduct of the winemaking process. As grape juice sits and ferments, potassium bitartrate precipitates and forms crystals on the inside of the casks which can then be collected and processed to make cream of tartar.
Cream of tartar has a slightly tangy, acidic flavor, but it’s not typically used in large enough quantities to impact the flavor of dishes. While you’ll find cream of tartar in spice jars and tins in the baking aisle, it also makes appearances in cleaning solutions. Mix it with white vinegar to make a paste that will shine up stainless steel, copper, brass, and porcelain.