Homemade Baking Powder

How many times when baking do you reach in the cabinet and think, "OK, was I looking for baking powder, soda or both? Ever wonder why it's one or the other or a combination?

Baking powders use an acid and base, which, when combined with a liquid, form bubbles that cause baked goods to rise. If there is already an acid in the recipe such as buttermilk or yogurt, you only need to add the base (baking soda) to get the bubbles. Simple enough.

Why do some recipes call for aluminum free baking powder? Because some commercial powders use an aluminum salt for the acid and it can give an unpleasant metallic taste to the finished product.

Is baking powder perishable? Yes. It can react with ambient moisture in the container and, therefore, have no bubbles to your fluff up your baking. Some commercial powders add cornstarch in an attempt to slow this process. To test your baking powder add 1 tsp to ½ cup hot water. If it doesn't bubble, it won't work to leaven your baked goods so it's time for a fresh batch. It's super simple to make your own.

Homemade Baking Powder Recipe
(makes about 1/2 cup)

1/4 cup cream of tartar
2 Tbsp baking soda

Sift together and store in an airtight container for up to a month. If it clumps, simply re-sift prior to use.
If you prefer not to make a whole batch, use 5/8 tsp cream of tartar and 1/4 tsp baking soda for each tsp of baking powder called for in a recipe. You could alternatively replace 1 tsp of commercial baking powder with 1/4 tsp baking soda in the dry ingredients and 1/2 cup buttermilk, yogurt or soured milk in the wet ingredients; decrease another liquid in the recipe by 1/2 cup. Or add 1/4 tsp baking soda to the dry ingredients and 1/4 cup molasses in the wet ingredients; decrease another liquid in the recipe by 2 Tbsp.

For more about baking powder, see the related How Stuff Works article.