Baking and dough
What is the difference between baking powder and baking soda?
The short answer. Baking soda is pure sodium bicarbonate and needs an acid to make bread and cakes rise, while baking powder already contains its own acid.
Recipes use baking soda with acidic ingredients like buttermilk, and baking powder when there is no acid to react with.
Both lose strength over time. Replace baking powder regularly, and test it by dropping a spoonful into hot water, where it should fizz.
Where it shows up in our recipes
Question
Can I substitute one for the other?
Not directly. They behave differently, so adjust only with a trusted substitution rule.