The Difference Between Baking Soda and Baking Powder

Almost every cook has faced encountered this scenario: you’re following a recipe that requires baking powder but you only have baking soda. What do you do? Can you substitute? Or this one: you haven’t baked for a while, you make a favorite biscuit and use baking powder, only to find that your biscuits bake up flat as hockey pucks. What went wrong?

Baking soda and baking powder are both leaveners used in baking, but they are chemically different. The easiest way to explain it is that baking soda is a base—it’s alkaline. Remember those experiments we did as kids, adding vinegar to baking soda to watch the eruption of bubbles? When you mix a base (baking soda) with an acid (vinegar) you get a reaction (bubbles). So if you encounter a baking recipe that uses baking soda, often that recipe will have an acidic element as well, such as vinegar, lemon juice, buttermilk, or yogurt. When the two come into contact, bubbles of carbon dioxide are formed, creating the leavening in your dough or batter.

Baking soda will create leavening on its own when it is heated (try pouring boiling water over baking soda in a sink to help unclog a drain, it will bubble up!), but unless it is balanced with an acidic ingredient, the resulting taste may be metallic.

Baking powder is a mixture of baking soda and a dry acid, such as cream of tartar, and perhaps some corn starch to help keep the two separate and dry. Most baking powders on the market are “double acting”, meaning that some leavening occurs the minute the baking powder gets wet, and the rest of the leavening occurs when it is heated.

How long do baking soda and baking powder last?

It depends on storage conditions. Baking soda can last quite a long time if stored sealed in a cool, dry space. Baking powder however is problematic. It can last 3 months, or it can last a year. If you are in a humid environment, once opened, baking powder might not last more than a few months. Having ruined a dish or two with old baking powder, I try to buy small cans, and I write the purchase date on the side of the can, so I know how old it is.

How to test if your baking soda or baking powder are still good

The easiest way to test baking soda to see if it is still good for leavening is to put some in a small bowl and add a little vinegar to it. (Make your own baking soda volcano!) If it bubbles up, it’s still good.

The easiest way to test baking powder to see if it still works is to put some in a small bowl and add some water to it. If it foams up, it’s still good.

 

How to substitute baking powder for baking soda

If you have a baking recipe that calls for baking soda, and you only have baking powder, you may be able to substitute, but you will need 2 or 3 times as much baking powder for the same amount of baking soda to get the same amount of leavening power, and you may end up with something that’s a little bitter tasting, depending on the recipe. If a recipe calls for 1 teaspoon of baking soda, you’ll want to substitute with 2 to 3 teaspoons of baking powder. Just make sure your baking powder is still effective and not passed its use-by date.

How to substitute baking soda for baking powder

You can substitute baking soda for baking powder, if you increase the amount of acidic ingredients in the recipe to offset the baking soda. You’ll also need much less baking soda as it is 3 times as powerful as baking powder. You’ll need about a teaspoon of vinegar or lemon juice for every 1/2 teaspoon of baking soda.

You can also easily make your own baking powder.

How to make baking powder

If you live in a humid environment, or don’t bake that often, it might be easiest to make your own baking powder when you need it. To do so, you’ll need cream of tartar—a dry acid in powder form (no idea why it is called “cream”)—and baking soda.

How to Make Baking Powder

Baking soda is much stronger than baking powder. To make baking powder, mix one part baking soda and two parts cream of tartar. So, if you recipe calls for 1 tablespoon of baking powder, use 1 teaspoon of baking soda, mixed in with 2 teaspoons of cream of tartar. Homemade baking powder is not double acting, and will start to react as soon as it gets wet, so work quickly and don’t let your batter sit around!

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22 Comments

  1. Georgina Pritchard

    This is very interesting thanks Elise. I always thought there is a difference between baking powder and baking soda :). This is very helpful. I follow you and visit your site most of the time and tried your recipes and it is always a success!

    Thanks again!
    Georgina

  2. Melanie Kramar

    Thank you so much for sorting out this dilemma that has been plaguing me for years.

    So excited when I saw this. I’m from South Africa and always got confused when following international recipe sites especially when it calls for baking soda. Here in SA we have bicarbonate of soda and baking powder, and never knew which one to use when the recipe called for baking soda.

    • Pat

      Oh yes same as in Australia. Never knew what baking soda was, I guessed it was bicarb but wasn’t really sure what was the difference.

  3. Derek Hanson

    Thanks for this informative piece – I think we have all been struck by this dilemma before. Baking demands a greater precision than many other kinds of cooking, but when you get it just right, it is extra satisfying. (Looking forward to having a proper oven after three years of living in a small oven-less Japanese apartment!) best,
    D

  4. Lynn

    The information on how to make your own baking powder is very helpful, since I use it so rarely that I’m sure it’s gone bad on me and I didn’t realize it. Now all I have to do is remember how to make it when I need it!

  5. Weng Ladaran

    Thank you Elise. Very interesting!! I heard that baking soda also is a meat tenderizer, Is it true?

    • Elise

      Hi Weng, that’s new to me. It wouldn’t surprise me though. Baking soda is slightly caustic, so perhaps it could break down muscle fiber if left on long enough. You would want to wash it off before cooking. My mother used to put a paste of baking soda and water on our mosquito bite when we were kids to help stop the itching. It worked okay, but the thing that really worked? Meat tenderizer. Best thing for mosquito bites.

  6. Manjula Singhi

    Thanks good information.

  7. Mike C Smith

    Today I learnt a few things I should have researched before now. I often wondered why you have to use baking soda as I find the taste is not to my liking. the same with baking powder, I did not know it was a combination using some baking soda in the mix.
    Thanks very much for sharing I’m glad I dropped by from facebook.
    Mike

  8. Lindsay Eckhart

    Wow, today I learn a lot thanks to you, Elise. I’d always thought that baking soda and baking powder are different but don’t know what’s the actual difference. Really informative. Thanks.

  9. Renee

    Very good information about how to make our own baking powder – especially since I don’t like using any that has aluminum added to it.

  10. Peter

    Thank you for this article – very helpful.

    When making baking powder at home, can one use extra baking soda (e.g., use equal parts baking soda and cream of tartar) with the excess soda acting as a leavening agent only when it is heated and not immediately when wetted? If yes, how would one “fix” any residual metallic taste?

    If not, is there another way to recreate the “double acting” feature at home?

  11. Ynothbrook

    Grandiosas recomendaciones que nos has dado a conocer hoy ,aparte de sus funciones que yo ya sabia que es lo maximo para la digestión junto una cucharadita en seco te la tomas on un vaso de agua que ya le exprimiste el jugo de medio limón y nunca bas a tener problemas con tu estomago y digestión, saludos

  12. Lynn

    Thank you, I’ve wondered about this too, but I always thought they were two completely different things. About 40 years ago I was making cookies and was short on flour so I substituted some corn starch, it was white and powdery and was made from food. You know, wheat, corn, they’re both grains? Yup, I ended up with hockey pucks you could break your teeth on. I’ve never done any substitutions in cooking since.

  13. Joelle

    Thank you very much for the tip. I can’t use baking powder because of the cream of tartar (my husband reacts to it as it is usually made using sulfites) and had been substituting with baking soda. But I often got unhappy results ( taste too strong, for one). Now I will know.

  14. Tina

    Thank you. This is really helpful, and interesting, too.

  15. Nicole

    @Joelle, try using citric acid or “lemon salts” instead of cream of tartar. You can also substitute yoghurt for any milk in the recipe.

    • Joelle

      Thank you Nicole for the tip. However, I will probably use plain old freshly squeezed lemon juice, because of the potentially hidden sulfites in any store bought product. (My husband’s allergies make cooking very tricky!)

  16. Herb Klug

    How many years have I wondered about this topic??? I mean, if you follow directions exactly, you don’t need to know the difference, but there’s a part of me that has always WANTED to know. Excellent explanation. Thanks Elise!

  17. Lea

    Thank you so much for this!

    I use far more baking powder than baking soda (pancakes, muffins, etc.) and have had a VERY hard time finding it in the stores lately (someone said it’s a “seasonal” item only now in many stores). I rarely use cream of tartar but now I know that I can use that with the baking soda to make baking powder if I need to! I knew they were related but never knew how before!

    Thanks so much,
    Lea

  18. Kate @¡Hola! Jalapeño

    What a great refresher! Also, I never knew that this is why my baked goods sometimes tasted metallic, lightbulb moment!

  19. Strawberry

    Thank you for these useful information.

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