Baking powder

Baking powder is a dry chemical leavening agent, a mixture of a carbonate or bicarbonate and a weak acid. The base and acid are prevented from reacting prematurely by the inclusion of a desiccant such as cornstarch. Baking powder is used to increase the volume and lighten the texture of baked goods. It works by releasing carbon dioxide gas into a batter or dough through an acid–base reaction, causing bubbles in the wet mixture to expand and thus leavening the mixture.

In 1843, the first single-acting baking powder (meaning that it releases all of its carbon dioxide as soon as it is dampened) was developed by pharmacist Alfred Bird in England. In 1856, Eben Norton Horsford, the Rumford Professor at Harvard University, received an American patent, for monocalcium phosphate, for baking powder. In the 1860s, Eben Norton Horsford developed the first double-acting baking powder, which releases some carbon dioxide when dampened and later releases more of the gas when heated by baking.

Baking powder is used instead of yeast for end-products where fermentation flavors would be undesirable, or where the batter lacks the elastic structure to hold gas bubbles for more than a few minutes, and to speed the production of baked goods. Because carbon dioxide is released at a faster rate through the acid–base reaction than through fermentation, breads made by chemical leavening are called quick breads. The introduction of baking powder was revolutionary in minimizing the time and labor required to make breadstuffs. It led to the creation of new types of cakes, cookies, biscuits, and other baked goods.