Baked Goods Falling Flat? This Could Be the Culprit

Unless you're a dedicated baker, it's unlikely that you'll go through an entire package of baking powder or soda before it loses its efficacy. (Baking powder has a shelf life of about a year, while baking soda should be replaced every two to three years.) This might not seem like a big deal — neither leavener will make you sick if consumed past its prime — but expired baking powder or soda won't provide as much rise in baked goods and can leave you with flat, dense cakes and cookies. Thankfully, there's a very easy way to test each for freshness:

To test baking powder's freshness: Add a spoonful of baking powder to about half a cup of boiling water. If the baking powder doesn't fizz and bubble, it should be replaced.

To test baking soda's freshness: Add a spoonful of baking soda to about one tablespoon of vinegar. If the baking soda doesn't fizz and bubble, it should be replaced.