What is the difference between baking soda and baking powder? Why do some recipes call for one, some for the other, and some call for both?
Baking soda, or bicarbonate of soda, releases carbon dioxide when it comes into contact with an acidic liquid. The resulting air bubbles help whatever you are baking rise.
Now, baking soda can be a great leavener if you have an acidic ingredient in your recipe, like buttermilk or lemon juice. But if you don’t have enough acid in your dough, your baking soda needs a little help.
This is where baking powder comes into play. Baking powder is simply baking soda, with added acid salts. The salts and the baking soda do not react together when dry, but when combined with a liquid, they will create carbon dioxide bubbles are produced to help leaven the dough.
So now we have baking powder to leaven no or low acidity recipes, and baking soda to help acidic goods rise. Why do some recipes, then, call for both baking powder and baking soda?
Sometimes, you want to neutralize the acid in a recipe. The baking soda achieves this, and the baking powder actually achieves the leavening.
What do you do if you don’t have any baking powder? Simple! Substitute with a mixture of two parts cream of tartar with one part baking soda.
And if you don’t have any baking soda? Just replace with baking powder, and increase the amount by two or three times. Be warned, however, that this could affect the final taste. You may be better off just running to the store to get a box of baking soda!