Does Baking Powder Have a Shelf Life

Did you know that baking powder has a shelf life? Unopened baking powder remains good indefinitely, but once you open a container of baking powder its potency starts to wane. The ingredient in the baking powder that would react with liquid in your recipe reacts instead with water vapor in moist kitchen air. You can slow this process by making certain your baking powder is tightly sealed when you arent using it. Test Baking Powder Its a good idea to test baking powder before using it in a recipe. Mix a bit of warm water into a small amount of baking powder. If you see bubbles of carbon dioxide form, then your baking powder is good. If no bubbles are formed or the reaction seems weak, its time to replace your baking powder. If you only get a few bubbles from the reaction with warm water, but cant get fresh baking powder in time to make the recipe, you can either use a bit more baking powder or else make homemade baking powder from baking soda and cream of tartar.