Become a better baker by learning the real differences between baking powder and baking soda—in easy-to-understand language!
Welcome back to my Baking Basics series!
Today I’m discussing one of the most confusing subjects in the entire realm of baking. What is the difference between baking powder and baking soda? Are they the same? Can I sub one for the other without changing anything else?
If there is one thing that you take away from today’s lesson, let it be this: baking powder and baking soda are absolutely not the same.
Baking powder and baking soda are both leaveners, however they are chemically different.
What is Baking Soda?
Aka bicarbonate of soda or sodium bicarbonate.
Let’s start with baking soda because it’s the most confusing. First, baking soda is a BASE. Do you remember the science experiment we all did in school? Mixing baking soda with vinegar and watching an eruption of bubbles? Usually we did this in some sort of model volcano contraption. I know you know. When you mix baking soda (BASE) with vinegar (ACID) you get a chemical reaction (an eruption of bubbles!). A product of this reaction is carbon dioxide.
The same exact reaction happens in our cookies, cakes, breads, etc. When a recipe calls for baking soda (BASE), it usually calls for some type of ACID like buttermilk, brown sugar, yogurt, lemon juice, vinegar, cream of tartar, molasses, applesauce, natural cocoa powder (not dutch process), or honey. You need this ACID in the recipe to react with the baking soda, which in turn creates carbon dioxide and allows your baked good to rise.
Baking soda is strong. In fact, it is about 3-4x stronger than baking powder. More baking soda in a recipe doesn’t necessarily mean more lift. You want to use *just enough* to react with the amount of acid in the recipe. Too much baking soda and not enough acid means there will be leftover baking soda in the recipe. You do not want that; it creates a metallic, soapy taste in your baked goods. Ick.
Good rule of thumb: I usually use around 1/4 teaspoon of baking soda per 1 cup of flour in a recipe.
Baking soda CAN leaven a baked good when exposed to heat. However, unless it is neutralized with an acid, your finished baked good will likely have a metallic aftertaste—like I mention above. Get it? Got it? Good.
What is Baking Powder?
Baking powder contains baking soda. It is a mixture of baking soda, cream of tartar (a dry acid), and sometimes cornstarch. These days, most baking powder sold is double acting. This means that the first leavening occurs when baking powder gets wet—like when you combine the dry and wet ingredients in the recipe. (This is why you cannot prepare some batters ahead of time to bake later—because the baking powder has already been activated.) The second leavening occurs when the baking powder is heated.
Double (first, second) acting.
Since baking powder already contains an acid to neutralize its baking soda, it is most often used when a recipe does not call for an additional acidic ingredient. Like my sugar cookies. However, this isn’t always the case. You can still use baking powder as the leavening agent in recipes calling for an acidic ingredient. Like my lemon blueberry cake. In my recipe development, I based my lemon cake recipe off of my vanilla cake recipe. I used buttermilk (acid) instead of regular milk for added moisture and a little tang and subbed a little brown sugar (acid) for granulated sugar—again, for added moisture. I was pleased with the rise and taste of the cake, so I did not experiment with using baking soda.
Good rule of thumb: I usually use around 1 teaspoon of baking powder per 1 cup of flour in a recipe.
Why do some recipes call for both?
Some recipes call for both baking powder and baking soda. These recipes contain some sort of acid (yogurt, brown sugar, etc), however the carbon dioxide created from the acid and baking soda is not enough to leaven the volume of batter in the recipe. That’s why baking powder is used as well—to add necessary lift.
Basically, the reason for both is because sometimes you need more leavening than you have acid available in the recipe. It’s all about balance.
Another reason to use both baking powder and baking soda is because they affect both browning and flavor. Food & Wine breaks it down easily: let’s take my birthday cake pancakes recipe. In my recipe, buttermilk is used partly for its tangy flavor. If we used only baking soda, it could neutralize all of the buttermilk’s acid. And we’d lose that tanginess! However, by including baking powder as well (which has its own acid), some of the buttermilk’s flavor is left behind, and there is still enough leavening for fluffy pancakes.
How to Substitute Baking Powder and Baking Soda
It’s tricky, which is why I never recommend it without background knowledge (and the expectancy that your baked good will not taste as intended).
If you have a recipe calling for baking soda, you might be able to substitute baking powder. However, you will need up to 4x as much baking powder to get the same amount of leavening. And, depending on the recipe, you might end up with a baked good that’s a little bitter with that much baking powder. You can sub baking soda for baking powder only if you increase the amount of acid in the recipe—which likely changes the taste and texture of your baked good. You’d also need less baking soda since it is about 3-4x stronger.
So, uh, just stick to the recipe!
Don’t Forget—They Expire!
I replace my baking powder and soda every 3 months, just to be sure they are always fresh for my recipes. I always date them on the bottom of the container. If you don’t bake often, chances are you’ll have to test your baking powder and soda for effectiveness before using.
How To Test Baking Powder
To test baking powder, pour 3 Tablespoons of warm water into a small bowl. Add 1/2 teaspoon of baking powder. Give it a light stir. The mixture should moderately fizz if the powder is fresh. If there is no reaction, toss the baking powder and buy a fresh package.
How To Test Baking Soda
To test baking soda, pour 3 Tablespoons of white distilled vinegar into a small bowl. Add 1/2 teaspoon of baking soda. Give it a light stir. The mixture should rapidly bubble if the soda is fresh. If there is no reaction, toss the baking soda and buy a fresh package.
That’s it for today! Did I completely bore you? Hello?
For anyone still here, don’t forget that baking is CHEMISTRY and it takes practice, trial and error, and the willingness to learn in order to succeed.
Stay tuned for a massively tasty chemistry project tomorrow. Cookies!
I am confused… you said the rule of thumb is 1 tsp of baking powder per 1 cup of flour, but your sugar cookie recipe calls for 2 1/4 C flour and only 1/2 tsp of baking powder?
Hi Maranda! There are exceptions, of course, and one of those is sugar cookies whose shape is imperative. Too much baking powder = cookies will puff up and lose their shape.
Excellent explanation!!
Great explanation! A quick comment–you don’t need to toss your old baking powder and baking soda. Both are still good as cleaning products. I use my old baking soda to get tea and other stains off of my dishes and to scour baking sheets with baked on grease. Even old baking powder can be used to clean pots and pans with the addition of a bit of vinegar. Waste not!
Thanks for the great tip, Sandra!!
This is fantastic! Thanks for pulling it all together like this!
Wow! You did an amazing job explaining this! I love baking and I love chemistry. It is wonderful to understand what purpose each ingredient serves. Thank you!
This is amazing! Thank you!! I am a science geek and I think that having this knowledge helps us all become better bakers!!
Great explanation–thank you! I can now play around with a recipe and feel like I know what I am doing and why.
A long time ago, I leaned the hard way that there is a big difference between baking soda and baking powder. By not paying close attention to my recipe, I used one when I should have used the other, and the result was an inedible pan of cornbread–served to company, no less! After making another cornbread recipe this week that tasted unpleasant, I decided to get to the bottom of this b.s. versus b.p. issue, so I googled it, found your site along with answers to my questions. Thanks for taking the time to shed some light on these two essential baking products that most of us know nothing about!
I really think I finally understand! Thank you so much. This question bugs me constantly. Same recipe , one ingredient different! I then spend hours on the internet trying to find as many recipes that are most alike – yes it’s extremely time consuming and I still don’t know for sure what to use! This article explained it so well that I believe I finally have it down.Of course Im also saving this page and site just in case I forget. Thank you so very much for the information and in understandable text. You’ve just helped my love of baking immensely and I thank you! Ill be checking back time and again for more tips or if I have a question. Especially with the baking season upon us!! Thank you Sally and I hope you keep giving us answers!!
Well, this changes everything! Thank you for one of the most enlightening—if not the most enlightening—revelations about the mysterious workings of leavening I’ve ever read, and written in general reader terms no less. I (and my future muffins, quick breads, cookies, and you-name-its) are very sincerely forever in your debt!
Wow, this was actually VERY helpful. I myself am an amateur baker, and I love it sooo much! It’s my favorite thing to do (besides eat em;) haha) but I always want to improve my baking skills and learn to make up my own recipes and I know the leavening is a big part of being able to do that. This was a big help! I’ve a real passion for baking and that won’t ever change, but maybe my recipes will ;D thanks for the tips Sally, keep ’em comin’ 🙂
Thanks for the VERY clear and complete explanation of the differences between baking powder and baking soda. I just made a batch of apricot white chocolate chip cookies (which I have made many times before) and mistakenly used powder instead of soda – oops. They came out rather dense and your write up helped me understand why. Your chemistry lesson about acids and bases with examples was truly enlightening! And especially the info about the difference in strength between soda and powder. I get it!!!! Yay!! Somewhere in the back of my head, I had heard about the importance of balance in baking, but the information was given so long ago, there was just no hope of retrieving it. Never knew brown sugar was an acid. Live and learn. Thanks for a terrific post!
Thank you so much – this was immensely helpful 🙂
This is a great resource for baking! I have looked at other websites to get information on the differences between sodas and powders and your blog really explains it the best!
Oh my gosh, Sally I am pinning this to my Kitchen Hacks board because it is a post I am sure I’ll be referencing time and time again down the road. I think you ought to do a guest appearance on Alton Brown’s show on Food Network… I don’t even know if that show is still on since we haven’t had Food Network channel in quite some time but I loved all that I learned from watching it when my youngest was just a baby.
I LOVED this post Sally!! Definitely have always wanted to know this!!
Sally, I absolutely LOVE your technical, scientific baking posts. Breaking it down into layman’s terms can be difficult, but you are very good at explaining. Baking is a science, and there is always a method to our “madness.” Because I’m a geophysicist, I appreciate the technical aspects of baking and enjoy it WAY more than making meal food…
Such a great, informative, and helpful post!! Thank you!
You must have read my mind! Haha Just yesterday, I was baking a peanut butter sheet cake and almost used powder instead of baking soda and after that my mind went into tangles trying to figure out exactly why I couldn’t use one instead of the other. Always learn something new!
Your side explanations of your recipes are the reason I can now skim a recipe and know if I want to try it or not. 🙂 I love understanding things better – so helpful!
Hi Sally,
I really enjoyed this post. LOVE the nerdy/sciency stuff!! I’ve learned a lot from you & your blog already & hope to continue learning…. Thanks so much! Getting ready to make your blueberry scones in a minute….. 🙂
Thank you, Sally! These tips are so interesting and helpful. I love learning about the ingredients, rather than just throwing them in and hoping the end product turns out! 🙂
I never learned the difference between baking soda and baking powder untill now. Thanks for the lesson. I hope to learn more new things besides the recipes from you. You’re such a good help to us.
Thank you for this!!! I’ve always wondered what the difference was and you explained it perfectly! I finally bought your first cookbook (been following you blog for a year now) and my son and I can’t pick what to make first! So excited!!
Thanks for this Sally! I found it quite helpful, despite the fact that I’m someone who bakes a lot and pretty much always knows what’s going on. The one thing I never change about a recipe until after baking it a first time is the leavener — disasters can happen that way :/
Great post! I’m trained as a chemist, so I appreciate the science talk! Although I understand acid-base chemistry when it comes to chemicals/drugs, that somehow doesn’t translate to cooking & baking for me. However, I’ve found that I enjoy being in the kitchen, so I’m trying to learn–this post is very helpful!
I learned something new today – thank you! I love enlightening things like this!
I love learning more about the science of baking! I’ve learned about this difference before but have never really understood it until you explained it, thanks! I’ll be looking out for more baking basics posts!