Baking soda makes cookies spread and brown. Baking powder makes them rise and stay cakier. They are not interchangeable, and swapping one for the other will change your cookie noticeably.
What is the difference between baking soda and baking powder?
Baking soda is pure sodium bicarbonate. It needs an acid to react, and it reacts immediately on contact. In cookie dough the acid usually comes from brown sugar, molasses, or buttermilk.
Baking powder is baking soda plus a powdered acid already mixed in, plus starch to keep them apart. It does not need anything else in the recipe to work. Most baking powder is double acting, meaning it reacts once when wet and again when heated.
What does baking soda do to cookies?
Two things. It produces carbon dioxide, which lifts the dough. And it raises the pH of the dough, which speeds up browning and weakens gluten. The result is a cookie that spreads more, browns deeper, and has a chewier texture.
This is why most chocolate chip cookie recipes use soda rather than powder.
What does baking powder do to cookies?
It gives lift without changing pH much. The cookie rises rather than spreads, and stays paler and softer. The texture is cakier and more tender.
If your cookies come out puffy and cake like when you wanted flat and chewy, baking powder is often why.
Can you substitute one for the other?
Not cleanly, but here is the closest you can get.
- Powder instead of soda: use about three times as much. You will lose the browning and the spread.
- Soda instead of powder: use about one third as much, and add an acid such as cream of tartar or a spoon of yogurt. Without acid you will get a soapy metallic taste.
If you have the choice, buy the right one. Substituting works in an emergency but it is not the same cookie.
Why do some recipes use both?
Because they want different things from each. The soda handles browning and spread, the powder handles lift. Recipes that call for both are usually aiming for a cookie that spreads a little but still has some height.
How do you know if yours is still good?
Baking soda: drop a pinch into vinegar. It should fizz hard immediately.
Baking powder: drop a spoonful into hot water. It should bubble right away.
Both lose potency over time, especially once opened. If either reaction is weak, replace it. Old leavening is a common and invisible reason cookies come out wrong.
Frequently asked questions
Why do my cookies taste metallic or soapy?
Too much baking soda with not enough acid to neutralize it. Reduce the soda or add an acidic ingredient.
Does baking soda make cookies brown faster?
Yes. It raises pH, which accelerates the browning reactions that give cookies their color and flavor.
How long does baking powder last?
Generally about six months after opening. Write the date on the can.
Who we are
Star Cookies is a small batch bakery in Orlando, Florida making thick stuffed cookies with a filling sealed inside the center. Details like this are why we bake in small batches instead of mass producing. Leavening, butter temperature, and portioning all have to be right, and they stop being right the moment you scale for volume.
We ship nationwide. Ferrero Rocher is our best selling flavor, with Dubai Chocolate close behind.