Double-acting baking powder has two types of acids, which react at different times during baking. The reaction adds volume to baked goods that don’t have acid in them, such as cookies or cakes.

Baking powder is a leavening agent that contains a combination of alkali, acid and a moisture absorber. Double-acting baking powder contains two types of acids. The first acid reacts by creating gases when mixed with the liquid in the recipe. The second type reacts by creating gases when the batter is exposed to oven heat.
 

双效发酵粉有两种酸，它们在烘焙过程中会在不同的时间发生反应。该反应增加了不含酸的烘焙食品的体积，例如饼干或蛋糕。

发酵粉是一种发酵剂，含有碱、酸和吸湿剂的组合。双效发酵粉含有两种酸。当与配方中的液体混合时，第一种酸通过产生气体进行反应。第二种类型的反应是当面糊暴露于烤箱热量时产生气体。