Demystifying Baking Powder: The Only Guide You Need (Plus How to Test Leavening Agents for Freshness)
Baking powder is a leavening agent made of baking soda and an acid. It reacts with batter and dough, causing baked goods to rise to a light, airy consistency. Read on for everything you need to know about baking powder, its role in the science of baking, and appropriate substitutions for when yours expires or runs out.