Baking powder is one of those ingredients that can linger in your cupboard for a long time. Most recipes need only a teaspoon or two of baking powder and even if you do a fair amount of baking at your house, it can still take months to use it up. If it’s been sitting around for too long, it will lose its ability to leaven the baked goods and could result in a final product that is less than you hoped for. Let’s look at a few strategies for determining if your baking powder is still potent, and a way to make your own baking powder if you’re in a pinch.
Most cans of baking powder will have a date stamped on the bottom that is the suggested expiration date of when the product is no longer at its best quality. This can be your first clue as to how old your container of baking powder is. A quick look at the bottom of the container in my cupboard showed a date at least a year away. I don’t remember exactly when I bought this container of baking powder (sometimes I can’t even remember what I ate for lunch!) but I would guess it’s been several months. Therefore it appears that the expiration dates stamped on baking powder are at least 1-1/2 years to 2 years out.
The second thing you can do to check the potency of your baking powder is to add a teaspoon of the baking powder to 1/3 cup of hot water. If it fizzes, foams, and bubbles up, the baking powder is still active and good. If it just sits there, then your baking powder is past its prime.
So what can you do if you’re in the midst of making the muffins and discover the baking powder has become a dud? If you have baking soda, cream of tartar, and cornstarch in the house, you can create a homemade version that might not have quite as much power as the real thing, but will be able to tide you over.
Make Your Own Baking Powder
1-1/2 teaspoons baking soda
3 teaspoons cream of tartar
2 teaspoons cornstarch
Combine the baking soda, cream of tartar, and cornstarch and use in the recipe as you would the baking powder.
And here’s one last thing to remember. Moisture will make the baking powder loose its potency so never dip a damp measuring spoon into your container of baking powder.