
I love baking. Following various recipes and always having a question in my mind. What is the difference between baking powder and baking soda. I finally got a chance to do some research on the web. Here is the answer:
First of all, baking soda is the same as bicarbonate of soda.
Both baking powder and baking soda are leavening agents, which cause
doughs to rise. They do
this via a chemical reaction that releases carbon dioxide gas. This gas
then forms bubbles in the dough, causing it to rise.
Baking soda is pure sodium bicarbonate. It needs
some sort of acid to activate the reaction. So it works in recipes
that include acidic ingredients like buttermilk, sour cream, lemon
juice, yogurt, etc. The
reaction begins immediately upon mixing the ingredients, so you need to
bake recipes which call for baking soda immediately, or else they will
fall flat! Beware if you were to try to substitute baking soda for baking powder
in a recipe where no acidic ingredient is present, there will be no
release of gas and the dough won't rise.
Baking powder, on the other hand, is nothing more than baking soda with
some sort of acidic compound already included. The baking soda and the acidic
compound won't react together until they are moistened, which causes the
two chemicals to mix. It is available as
single-acting baking powder and as double-acting baking powder.
Single-acting powders are activated by moisture, so you must bake
recipes which include this product immediately after mixing.
Double-acting powders react in two phases and can stand for a while
before baking. With double-acting powder, some gas is released at room
temperature when the powder is added to dough, but the majority of the
gas is released after the temperature of the dough increases in the
oven.
There are other types of leavening agents. Yeast is made up of tiny
micro-organisms. When they consume sugar, they release gas. Steam can
also be used as a leavening agent. This technique is used in making puff
pastry, where the dough is folded over again and again, forming many
thin layers. The steam that is released during cooking puffs up the
layers, causing the dough to rise. Air can also be beaten into to doughs
and batters through the creaming method.