With few exceptions, baking works with either yeast or chemical reactions. Understanding these chemical reactions will make you a better baker. It’s a pretty simple reaction:
Mix an Acid with Base = Carbon Dioxide (a gas)
That’s what makes baking work! The most common base (or alkaline) is baking soda. But it’s useless without an acid.
The most common acid is buttermilk. Mix the two together to create a gas in your batter and your cookies rise and your pancakes are light and fluffy.
(Baking powder has both a base and acid and is activated by water and heat.)
But follow the recipe closely. The amount of acid and the amount of base is important. If there is a perfect match between the acid and the base, the acid is neutralized but the amount of gas is maximized. If you have more acid than base, you will taste a residual tang of buttermilk—desirable in some recipes. If you have too much soda, you will taste that too—that’s undesirable.
For the buttermilk, you can use either liquid or dry buttermilk. I prefer dry. I hate curdled buttermilk in my refrigerator. Worse, I hate not having buttermilk when I’m getting ready to start a recipe. And it costs less.
Dry buttermilk saves you money in two ways: it doesn’t spoil in your refrigerator and it costs much less per ounce.
Tip: And you don’t have to mix the water and buttermilk powder together. Just add the water to your recipe and an appropriate amount of powder and the two will mix together as you mix the batter.