Did you know that baking powder and baking soda have expiration dates? After sitting on the shelf for a long time, they will lose their freshness or leavening properties. To help ensure your baked goods will rise properly, make sure you’re using fresh baking powder and baking soda. This simple test will help you determine if it’s still fresh or if you need to buy new.
Put a half teaspoon of baking powder into a glass bowl. Pour in a half cup of boiling water. The mixture should bubble and fizz until it’s foamy. If there is only a small amount of bubbling, or none at all, you should throw the rest of it away and buy fresh baking powder.
Put a half teaspoon of baking soda into a glass bowl. Pour in 1/4 cup (or thereabouts) of vinegar or another acidic liquid (like lemon juice). The mixture should foam and rise, reminiscent of those school-days science project volcanoes we used to make. And just as with the baking powder, if there isn’t much reaction happening you should replace your baking soda with a new box.