Aluminum-free Baking Powder
Here's a healthy alternative to store-bought baking powder that's easy to make, and works just as well. Aluminum-free, gluten-free and optionally corn-free.
1 part baking soda
1 part starch (tapioca starch or corn starch)
2 parts cream of tartar
Mix together. If kept cool and dry in a sealed container, it will last up to a year. To test and see if it's still active, mix a bit into some warm water - it should fizz up.
Adapted from this recipe.