Baking soda is also called Sodium Bicarbonate or Bicarbonate of Soda, as seen on this old-fashioned drugstore bottle.
Baking soda is pure Sodium Bicarbonate, a naturally occurring white crystalline substance with a number of household uses. When it comes to baking, sodium bicarbonate is the leavening agent that helps turn out light, airy breads and cakes of great heights.
This rising action happens when the baking soda is mixed with an acidic ingredient in your recipe. This could be something like lemon juice, buttermilk, sour cream, cocoa or molasses. When the soda comes in contact with this acid, it produces carbon dioxide gas bubbles which expand your batter and make your baked goods rise in the oven.
Many recipes will instruct you to mix baking soda with other dry ingredients before adding liquid. They might also tell you to mix briefly or "only until moistened." Working this way keeps the baking soda from reacting until the end of the mixing process. If you were to over-stir your batter or let it sit too long, the bubbles would escape. To keep your cakes and breads from falling flat, get your mixed batter in the oven as quickly as possible.
Since baking soda absorbs the odors around it, store in a separate airtight bag or container in a cool, dry place. Some brands take care of this for you with convenient resealable packages. If you remove the soda from its original box, make sure to mark the expiration date on your new container.
If you aren't sure how long your soda's been sitting in the pantry, you can test its effectiveness. Pour two teaspoons of vinegar or lemon juice in a cup and add 1/4 teaspoon of soda. If the mixture fizzes, the soda is still active and good for baking.
There is absolutely no substitute for baking soda. However, you can use baking soda to make a substitute for baking powder.
To make the equivalent of one teaspoon of baking powder, mix 5/8 teaspoon of cream of tartar with 1/4 teaspoon baking soda.
Try one of our favorite baking soda recipes: