double-acting baking powder

Double-acting baking powder is a leavening agent composed of baking soda (sodium bicarbonate), one or more acid salts, and cornstarch as a moisture-absorbing filler. Unlike single-acting varieties, double-acting baking powder produces gas in two stages: first when mixed with wet ingredients at room temperature, and again when exposed to heat during baking. The acid components typically include sodium aluminum sulfate and/or monocalcium phosphate, which react with the baking soda at different rates—monocalcium phosphate reacts immediately upon hydration, while sodium aluminum sulfate reacts primarily when heated above 60°C (140°F). Cornstarch serves as an anti-caking agent, preventing premature activation and moisture absorption during storage.

Double-acting baking powder is the standard leavening agent in baking, producing uniform rise and tender crumb in cakes, quick breads, biscuits, pancakes, muffins, and cookies. Its dual-action mechanism allows bakers greater flexibility in timing, as the initial gas release upon mixing is supplemented by additional lift during baking, ensuring consistent rise even if batter sits briefly before entering the oven. It is particularly useful in recipes where extended mixing or standing time is unavoidable. Double-acting baking powder is also used in batters for fried foods and in some instant pudding and sauce preparations.