Baking Powder in Yeast Breads...greenspun.com : LUSENET : Cooking & Crafts : One Thread
Info provided by a "baking technologist":
Marie, I would never use baking powder in a yeast bread. There's just no need. Baking powder is a mixture of baking soda, which is basic (or alkaline) and one or more acid salts, and generally corn starch to keep the acid and base separate as well as absorb excess humidity.
When baking powder is wetted the acid neutralizes the baking soda and the soda releases carbon dioxide.
There are two types of baking powder, single and double. There are two types of single acting, fast and slow, in fast acting the acid immediately reacts all the baking soda and releases all the CO2. In slow acting the acid salt will not solubilize until it reaches high temperature, and then reacts with the soda.
Double acting has some of both types of acid salts and often will have a fast, intermediate, and a slow acting acid salt. Bread made with baking powder is likely to have a bisquit like flavor.
Many of these Pillsbury bread in a can products are chemically leavened, as are the self rising pizza crusts that you can buy such as DiGiorno etc... if you know what these taste like.
One of the problems with baking powder in a yeast leavened product is that even if you are using a slow acting acid salt the acid produced by the yeast will neutralize the soda long before the acid salts are solubilized.
This is going to raise the pH of your dough, something that you don't necessarily want, as the acids provide an important part of the flavor profile of your bread. The acid salts will eventually solubilize in the oven lowering the pH of your bread, but these are not the same acids.
I'll end here if anyone really wants to know more about chemical leavening let me know. Dan
-- Marie (email@example.com), February 08, 2002