Dear Heloise: I've got a problem! Sometimes my cookies, muffins, cakes and biscuits don't rise enough. I was told that there is a test for checking the freshness of baking powder. I tried this and was ...

Life feel flat?: If your cookies and muffins don’t seem to rise as much as they used to, check your baking powder. It tends to last for about 6 months or so, then it loses its strength pretty quickly.

If you've gone to all the trouble of baking a homemade cake or batch of cookies, only to find they came out flat or dense, your leavening agent might be to blame. While baking powder and baking soda ...