Composition

• Baking powder consists of 3 components: an acid, a base and a filler. A typical mixture includes cream of tartar (an acid), baking soda (a base) and cornstarch (a filler).

Varieties

• Baking powder is available in 2 varieties, single-acting and double-acting. Single acting baking powder bubbles only when it gets wet. Double-acting baking powder reacts twice – first when it gets wet and again when it is heated.

Ratio

• The golden ratio for baking powder to flour is 1-1 ¼ teaspoons to 1 cup. Too much baking powder in a recipe can botch the leavening process by generating an excess of bubbles that hastily rise to the surface and pop. (See Reference 2)

Storage

• Baking powder should be stored in an airtight container in a cool, dry, dark place. To determine if baking powder is still fresh, add one teaspoon of the ingredient to half a cup of boiling water. If the boiling surges and becomes fizzy, the baking powder is good.

Substitution

• To substitute for 1 teaspoon of baking powder, combine 1/2 teaspoon cream of tartar and 1/4 teaspoon baking soda. If the baking powder substitution will not be used immediately, add 1/4 teaspoon of cornstarch to the mixture. Cornstarch prevents a premature chemical reaction between the acidic cream of tartar and alkaline baking soda by absorbing moisture in the air. (See Reference 2)