Cream of Tartar

Cream of tartar is a fine white powder (potassium bitartrate) that forms naturally as a byproduct of winemaking, crystallizing out of the barrel as grape juice ferments. It has no flavor of its own — it's used purely for its chemical properties as a stabilizer and leavening agent.

Where It Comes From

Cream of tartar isn't grown or harvested from a plant directly — it's a mineral byproduct of grape fermentation, refined from the crystalline deposits (sometimes called "wine diamonds") that form inside wine barrels and tanks. Every cook simply buys it as a purchased powder.

Culinary Uses

A small amount of cream of tartar stabilizes whipped egg whites, helping meringues hold their peaks, and combined with baking soda it forms a homemade baking powder substitute. It's also added to sugar syrups to prevent crystallization, keeping candy and frosting smooth.