Baking soda is a white powdery substance used for cooking. Baking powder is a white powdery substance used for cooking. Although they look the same, they are radically different.
Baking powder and baking soda are both considered chemical leaveners that create volume and fluffiness in a recipe. But, they are NOT interchangeable.
Baking Soda (sodium bicarbonate (NaHCO3 ))
Baking soda requires a liquid and an acid in order to activate it as a leavening agent. Some naturally acidic ingredients that you will find in recipes that allow the baking soda to activate include:
- Sour Cream
- Brown Sugar
- Lemon Juice
- Natural Cocoa Powder (not Dutch Process – Learn about the difference)
Once baking soda comes in contact with a liquid and an acid it will begin to activate and create carbon dioxide. This is why recipes that only use baking soda as its leavening agent cannot be made ahead of time and stored until ready to bake. If you let a batter sit around too long, the leavening effect will be decreased.
Because of its higher ph level, baking soda helps create nicely browned crusts on baked goods.
Be careful not to use too much baking soda as it can leave a metallic flavour.
Baking powder is a chemical leavener that consists of a base (baking soda), an acid (like mono-calcium phosphate), and a drying agent (usually cornstarch).
You can, in fact, make your own baking powder with baking soda and an acid such as cream of tartar.
Unlike baking soda, baking powder does not require an acid for it to become activated. That is because it already contains an acid. It only requires moisture.
Baking powder usually comes in two variations: “single-action” and “double-action.” Double-action baking powder reacts first when exposed to a liquid and then again when exposed to heat.
Recipes that use double action baking powder can be made ahead of time because the rest of the leavening happens when it is exposed to heat.
You can substitute double acting baking powder if the recipe does not specify which one to use. But, it is not a good idea to substitute single action if the recipe specifically calls for double action (especially if there is a resting period for the dough or batter).
Test For Freshness
If you are not sure whether your powder or soda is fresh, do a quick test.
- Combine 1/2 Cup of hot tap water with 1/4 teaspoon of white vinegar
- Add 1/4 teaspoon of Baking Soda
- If it bubbles, it is fresh. If not, buy new soda
- Combine 1/2 Cup of hot tap water with 1/4 teaspoon Baking Powder
- If it bubbles, it is fresh. If not, buy new powder