How to Test Baking Powder: Is Your Baking Powder Still Good?

Baking powder is a chemical leavening agent common in recipes for baked goods, giving loft and fluffiness to foods like quick breads, pancakes, chocolate chip cookies, meringues, and cakes. It works by releasing gases into the batter or dough, creating pockets of carbon dioxide gas and causing it to expand (or rise) and achieve a lighter texture.

Baking powder is a combination of baking soda (sodium bicarbonate) and cream of tartar (an acid). While similar leavening agents like baking soda need an additional acid to activate (think the baking-soda-and-vinegar volcanoes of elementary school science fairs), baking powder is a one-stop shop that already contains the necessary acid to create a chemical reaction and help baked goods rise all on its own.

Baking powder has a shelf life of about twelve months. Once it starts to expire, it will lose its rising properties and won’t bring much loft to baking recipes. Here’s how to test baking powder to make sure it’s still good:

1. 1. Boil ½ cup of water. Put some tap water on the stovetop, in an electric kettle, or in the microwave to boil.
2. 2. Spoon out one teaspoon of baking powder. Place one teaspoon of baking powder in a small bowl. It should be dry and powdery. If it’s caking or clumping, the powder may have encountered too much moisture. To remedy excess moisture, store baking powder in an airtight container, rest it in a dry place, or add a small amount of cornstarch to the container.
3. 3. Pour hot water over the baking powder. Once your hot tap water is vigorously boiling, carefully pour it over the baking powder using a measuring cup or other ladle. The baking powder should immediately begin to fizz and bubble—if it does, that means it’s fresh and good to use in baked goods. If your baking soda doesn’t bubble or only bubbles weakly, it may be past its expiration date and won’t have the proper results in the kitchen.

To test baking soda, combine one teaspoon baking soda with room-temperature white vinegar or another acidic ingredient like lemon juice or buttermilk. The baking soda should bubble and fizz when combined with acidic ingredients.

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