Most home bakers know that baking powder and baking soda can easily lose their punch over time. These key ingredients are vital to the success of many recipes, even if they only call for 1/2 a teaspoon here and there. During the baking process, leaveners like baking powder and soda break down and produce carbon dioxide. The result is the texture of the cookie or the tenderness of a piece of cake.
So how do you know if you baking powder or baking soda is still good? There's an easy test anyone can do in just minutes, using ingredients you likely already have at home:
How to Test Baking Powder:
Stir 1/2 teaspoon baking powder into 2 tablespoons of hot water. If it bubbles up or fizzes, the baking powder is still active and ready to use in baking. If not, it's time to head to the store and buy a new can.
In an emergency, you can make a substitute for baking powder. To make the equivalent of one teaspoon baking powder, combine 1/2 teaspoon of baking soda with 1/4 teaspoon of cream of tarter.
How to Test Baking Soda:
Stir 1/2 teaspoon of baking soda into 2 tablespoons of lemon juice or vinegar. You should see an acidic reaction almost immediately. If the baking soda doesn't fizz, save it to use for cleaning, but replace your box for baking.