Cream of Tartar
An acidic byproduct of wine making, used to stabilize egg white foams and prevent sugar crystallization.
1 Tsp Cream of Tartar = 3g • Blends with baking soda (2:1 ratio) to make baking powder
Cream of tartar is the common name for potassium hydrogen tartrate, a crystalline acid byproduct that forms on the inside of barrels during the wine making process. In baking, this fine white powder is highly valued for its acidic properties. Its primary application is stabilizing whipped egg whites. When egg whites are beaten, the proteins unfold and trap air. Adding a pinch of cream of tartar lowers the pH of the whites, which strengthens the protein bonds and prevents them from over-expanding and collapsing. This yields a glossy, stable meringue that holds its volume when baked or folded into batters.
In sugar syrups and candy making, cream of tartar acts as an interfering agent. The acid breaks down sucrose into glucose and fructose (invert sugar), which prevents sugar crystals from re-crystallizing, ensuring a smooth, velvety texture in fudges and caramels. It is also blended with baking soda to create homemade baking powder.
Omitting cream of tartar when making delicate angel food cakes or macarons. Without this acid stabilizer, the egg white foam easily collapses during folding, resulting in flat, gummy cakes.
Widely available in the spice aisle of grocery stores globally. In Europe, it is sometimes sold under its chemical name, potassium bitartrate.
Essential for whipping egg whites for meringues, soufflés, and angel food cakes, and for preventing crystallization in syrups and candies.
Replace 1/2 teaspoon cream of tartar with 1 teaspoon lemon juice or white vinegar (liquid acid equivalents).
Store in a cool, dry place in an airtight container indefinitely. Keep away from moisture to prevent clumping.