Baking soda, also referred to as sodium bicarbonate, is an integral part of many baking recipes. This is because baking soda is what causes your baked goods to rise in the oven and become fluffier.
Baking soda is basically a leavening agent. When it comes into contact with an acidic ingredient and a liquid, it becomes activated. And the reaction causes it to release carbon dioxide. This in turn causes the batter to expand (as if it is filling up with air), and it forms the typical texture found in cakes, and bread, and such.
If you don’t have any baking soda or don’t want to use it, you can replace the baking soda with just about any other leavening agent in order to have the same effect.
More often than not, if you try to bake any recipe that requires baking soda without any leavening agent whatsoever, then you can run into trouble. The baked goods won’t rise and will remain very dense, even when fully cooked.
For example if you tried to make banana bread without any kind of leavening agent such as baking soda or baking powder, you’ll be left with a flat piece of banana flavored rubber!