Previous definitions:
1.
A leavening agent, which when mixed with liquids, causes bread to rise by releasing carbon dioxide. It's a combination of an alkaline ingredient (usually baking soda), an acid (cream of tartar), and starch (cornstarch). The most common type of baking powder is double-acting, which releases some gas first when it becomes wet and then more when heated in the oven.
As defined by Mechanical Turk
on May 20, 2011
