Whenever he thought about it, he felt terrible. And so, at last, he came to a fateful decision. He decided not to think about it. ~John-Roger and Peter McWilliams
Question #2586 posted on 01/23/2004 midnight
Q:

Dear 100 Hour Board,
What's the difference between baking soda and baking powder?
- confused cook

A: Dear Confused Cook,

Baking powder is a mixture of baking soda, corn starch, and cream of tartar. Both baking soda and baking powder are used as leavening agents. You'll use baking soda in many types of cookies, and baking powder in things like cakes, biscuits, and other quick breads.

- The Chef
A: Dear CC-

From a chemical perspective, baking soda (sodium bicarbonate) is NaHCO3. Baking soda requires the addition of an acid to produce carbon dioxide (filling the product with "air" bubbles.

Baking powder, however, is sodium bicarbonate plus an included dry acid(s). Most baking powders now come "foolproof," that is, with double acting acids. Because both reactants are dry, they remain stable. The first acid reacts with water, the second with heat. So if you overbeat something, it can still rise in the oven.

The difference, then, between the two is what is required to create air in your bread/dough.

Atlas