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Research and Innovation

The Difference Between Baking Soda and Baking Powder

What’s the difference between baking soda and baking powder? Short answer: acid. But it can make a big difference for baked goods, so let’s explain.

This is what happens when baking soda and acid (in this case vinegar) interact. Photo credit: Kate Ter Haar, via Wikimedia Commons.

Baking soda has only one ingredient: sodium bicarbonate. Sodium bicarbonate is a base that reacts when it comes into contact with acids, like buttermilk, yogurt or vinegar. This reaction produces carbon dioxide (CO2) in the form of bubbles (think of the grade school experiments involving fake volcanoes, vinegar and baking soda). When making baked goods, this process is called “chemical leavening,” because the trapped CO2 gas makes the dough or batter rise.

But when baking soda comes into contact with an acid, it pretty much reacts immediately. And that’s a problem.

For many baking recipes, you want an extended reaction, so that the rising doesn’t take place all at once.

Baking powder addresses this problem because it is “double acting” — it has different ingredients that create CO2 gas at different stages of the baking process.

All baking powders contain sodium bicarbonate (just like baking soda). But baking powder also contains two acids. One of these acids is called monocalcium phosphate. Monocalcium phosphate doesn’t react with the sodium bicarbonate while it’s dry. But as soon as the baking powder is stirred into a wet dough or batter, the two ingredients begin to react, releasing bubbles of CO2 and causing chemical leavening.

But to extend the chemical leavening process, baking powder also contains a second acid, either sodium acid pyrophosphate or sodium aluminum sulfate. Neither of these acids react with sodium bicarbonate until they are both: A) wet (i.e., stirred into the batter) and B) hot.

In other words, sodium acid pyrophosphate and sodium aluminum sulfate won’t start reacting with the sodium bicarbonate until after you’ve put the dough or batter in the oven. This means that the batter rises for a longer period of time, making lots of bubbles (and a fluffier cake, muffin, or whatever).

At some point during the baking process, the liquid foam of rising batter becomes a solid foam, because the batter “sets.” This is one reason eggs are so common in baking recipes.

The proteins in eggs become irreversibly denatured when exposed to heat (that is, the proteins unfold and cannot refold into their original shape). These altered egg proteins essentially give the liquid foam a solid structure, allowing it to hold its shape.

By comparison, in recipes that use yeast as a leavening agent, the gluten proteins in flour serve a role similar to that of egg proteins in most chemically-leavened baked goods: the gluten proteins help trap air bubbles until the dough sets. (That’s why bread flour has more protein than cake flour.)

Special thanks go to Keith Harris, an associate professor in the Food, Bioprocessing and Nutrition Sciences Department at NC State and all-around food chemistry enthusiast. This post is part of an ongoing series in which we try to answer questions about the science behind food — from farm to fork. If you have a food-related question, please let me know at

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  1. Very informative
    Need more information on food chemistry and nutritional sciences.
    Dr Surendra Vyas,
    New Delhi India
    Email sskvyas

  2. Which other ingredients are contained in baker’s sodium bicarbonate?
    Can I just repackage 100% sodium bicarbonate (food grade) in small packs and sell on the market for baking?
    What is the shelf life of sodium bicarbonate in an intact pack.

  3. Thank you very much for this article. I am a nutritionist by profession. I have a lot of passion in baking the healthy way. Whether its cakes, pizzas, maandazis, breads, buns etc I try as much as possible to use healthy ingredients. I use the three products; baking powder, baking soda and yeast and it is great to understand how each of them works during the baking process. Thank you!

  4. I heard of sodium bi carbonate but realise now that it can also be used in baking. Your explanation was very informative as pertaining to chemical reaction dynamics. Thanks once again.
    D Pal

  5. all this chemistry – been so long since I took it in college, and I miss thinking about it. “live better through chemistry”. More like, “live period through chemistry”.

    ps – if the name is not taken already, shouldn’t you call your website “Baking Bad”?

  6. Thank you so much for your feeding our inquiring minds. In baking muffins can other ingredience be added to provide more lift in eg. Raisin muffins.

  7. Rub baking powder on pork and boil in water with salt. What is the function of the baking powder in this Colombian cooking method?

  8. I have a young great grandchild (7) who loves to read and study he has a very inquiring mind eg. most kids ask for sweets etc. he asks for citric acid etc. to help with his “experiments”. Thanks to you I can now explain the differences between baking powder and baking soda. Thanks again.

  9. Im a student now studying chemistry and this experiment is actually a chemistry lab report for us p&d and this really helped me out…..

  10. Whats the proportion between baking soda macp and sodium acid pyrophosphate tobe used when making baking powder

    1. Question: In the ” olden days” we used to use hydrogen peroxide and bicarbonate soda or was it baking powder? For whiter teeth. Could you please advise. Thanks

  11. Please I want to know if baking soda is in from of salt or dust like baking powder? I bought one but is in from of salt am confused

    1. If you mean in terms of shape and size of the thing, I presume it can come in “rocks” or granules like salt but it’s usually a slightly thicker powder than baking powder. That’s how we’ve had it in Ontario anyway.

  12. I thank everybody foe the wonderful contribution to this discussion of baking soda and baking powder. I have read in some papers that baking soda kills cancer cells, bacterial and viruses. Can someone help to give more information on this.

    1. It is highly unlikely to do any of that. Most of my aunts, uncles and Grand parents have had cancers, if baking soda killed it, they eat lots of baked goods with baking soda and thus wouldn’t have had cancer to begin with.

      1. Yes, but they also ate a TON of sugar and glyphosate in the process, which is deadly to your microbiome. Look at “The truth about cancer” on YouTube. You will be shocked on what you learn. I am an MD and metastatic cancer survivor.. This information saved my life.

    2. Cancer cells do not strive in alkaline environment, ph higher than 7. The foods that we eat are acids and alcaline so you have to measure the ph of urine. If you get cancer eat much more alcaline foods and drink good water with some baking soda.Cancer will disappear. For more check : Dr Otto Warburg or contact me.

  13. Thanks for the explanations. A side question, I have been using baking soda for cleaning purposes, wonder baking power will do the job? I m no good in science.

  14. I am sorry to get out of the subject but I would like to mention another use for Baking soda. When I was small and had a stomach ache or acidity my mother would squeeze some fresh lemon juice, add some sugar and when all sugar was melted she would add a tip of a teaspoon of Baking Powder and stir. It did foam up to the glass rim and it was delicious! And in a short time my stomach did not hurt anymore! (This must have been an old natural Italian remedy I guess, it worked every time!) Franco M

  15. For those who want to reduce sodium intake, is poassiuim bi-carbonate (and baking powder with potassium based acidic salts) useful for baking? Are these available ?

  16. Thanks for that explanation it settles an argument I was told they were the same but have seen recipes which call for both products which brought up the discussion.

  17. How fascinating! Thank you for explaining the difference between baking soda and baking powder! That’s another great “food” question for my foodie friends at the next cocktail party! I’ll use that one next after asking, “What’s the difference between a holandaise sauce and a bernaise sauce? Just the addition of ONE ITEM! Add terragon to a holandaise and voila, you’ve got a bernaise!

  18. I didnt want to hav the answer in science language. I want to knw what is the purpose of using baking soda in a cake and baking powder in a cake. Also, when to use both?
    Can someone plz answer me?

    1. Using too much baking soda can leave a bitter taste in some lightly flavored batters so baking powder is added also to prevent this. Both the baking soda and baking powder start the rise immediately when an acid and liquid are added. If double acting, the baking powder will continue to rise from the heat of the oven.

      The reason eggs are added is because the heat of the oven changes the structure of the egg protein so that the moist foam of the co2 bubbles is ‘set’ by the ‘cooked’ egg protein and the risen batter holds its shape. This is why most recipes say to mix the eggs into the batter until completely incorporated; it spreads the egg protein evenly throughout the batter to ensure an even rise with the baked goods.

      In the case of your cookies you get a lighter fluffier cookie than without both.

  19. Hi
    I have also read that Baking Soda is good for producing testosterone. Instead of using Baking Soda if I use Baking Powder (because I have it at home) will it do any harm for my stomach.

  20. Hi
    I read that a natural remedy for Constipation is to take Baking Soda with warm water. Instead of taking Baking Soda, if I take baking powder will it do any harm for my stomach.

  21. Thank you so much!!! This helped me withe my science fair project and better understand the differences between the two!!!! Thank you so much!!!!!! ;D

  22. what happens when both baking soda and baking powder (same amount each) are used in baked goods together?
    Thanks for your answer

    1. Using too much baking powder will make your bread rise rapidly, the bubbles get too large and collapse. I had this happen today while I was adjusting an oatmeal banana bread recipe to see how high I could get it to rise.

  23. The answer to your question Teresa Sully is right there in the text if you take the trouble to read it-carefully.

  24. neeraj kumar says Aug 1 …2015 11:53 pm..Thanks for Keith Harris difference bewteen baking powder and baking soda. ……

  25. Ok then what is the difference between baking soda, baking powder and bi carb soda..? Or is there another player … bi carb powder… btw I’m Australian and we usually deal with the latter two mentioned here. Thanks, Teresa.

    1. baking soda and bicarb of soda are one and the same thing, just different names, thats all….i have to remember that. Its baking powder thats different. It apparently contains bicarb of soda (or baking soda) as well as two acids, whose names are a bit too chemically intricate for me to mention here, which lengthens the rising of the dough process….

  26. Thanks for the answer,
    I had no idea it was so technical.
    A top UK chef, Jamie Oliver, did say when to use each, but I couldn’t remember why.
    thanks again

    1. Backing soda is to be used with acidic or fermented items where as baking powder is to be used with non fermented items which do not contain acids