Although it’s sometimes impossible to make a difference between baking soda and baking powder, they don’t share the same chemical composition.
Baking soda
It’s also called bicarbonate of soda or sodium bicarbonate. Its reaction with acidic ingredients releases carbon dioxide. If you add it to recipes, you will also need an acidic ingredient like yogurt, buttermilk, lemon juice, brown sugar, molasses, or cream of tartar.
Baking soda is stronger than baking powder. If it doesn’t neutralize, it may give you a metallic taste. Always follow the rule of the thumb. Add a quarter teaspoon of baking soda per every cup of flour.
Baking powders
It consists of baking soda, cornstarch, and cream of tartar. If you use it in cooking, make sure the first leavening happens when the powder gets wet, and the other when it’s heated. Here’s the rule of the thumb again. Add a teaspoon of baking powder per every cup of flour.
Some recipes work better with the combination of both baking powder and baking soda. It’s all about the balance, because carbon dioxide from baking soda and acids may affect the volume after the leavening.
Baking soda and baking powder have expiration dates. Always use fresh produce, and buy another every three months. Test the power of your product before every use. Put 3 tablespoons of white distilled vinegar in a small bowl. Add in half a teaspoon of baking soda, and stir well. If your baking soda is fresh, the mixture will sure be flooded with bubbles.