Baking Soda

Sodium bicarbonate (baking soda) is the baking world’s go-to chemical bubbling agent. It’s a crystalline alkaline powder which, once it’s combined with water, dissolves into sodium ions and bicarbonate ions, the latter of which react with acid to create carbon dioxide gas.

That’s all very straightforward, no? However the interesting thing about baking soda is that you can get reactions of different speeds depending on what sorts of acids you pair it with. Common kitchen acids (acetic acid from vinegar, lactic acid from sour cream) generally yield fast reactions, which is why it’s usually important to hustle anything leavened solely with baking soda into the oven as soon as you’re done mixing. This is especially true if the mixture is a fairly liquid batter, since a.) water facilitates a baking soda reaction and b.) CO2 bubbles will rapidly rise out of a liquid.

There are however acids that deliver rather slower reactions. I’ll discuss those in the post on baking powder, since sodium bicarbonate is a component of that as well.

I should say that when using baking soda it’s important that you have enough acid in your mixture to react all of it. Unreacted soda has a salty, sour taste. But it can deliver far worse tastes than that if the batter you’re making has much fat in it. For soda + fat + heat = soap, which is a very unwelcome thing indeed in a cookie.

19 thoughts on “Baking Soda”

  1. Can I tell you Joe that your timing is impeccable? It is! So here I am last night mixing up a new recipe for gingerbread. I am putting all my dry ingredients in a bowl, and I’m looking at the recipe to see where the leavening agent is for it is absent from the list of dry ingredients. I finally find baking soda at end of the ingredients list with 1 cup hot water and lemon juice. As I read through the directions, I see that the soda is not mixed with the dry ingredients, but rather dissolved into the hot water and then added to the batter alternately with the flour mix and then the lemon juice at the very end. I thought this was rather odd since hot water would immediately activate the soda and you would lose some of the leavening power just dissolving the soda into the water. The batter was very liquid and not very bubbly, but the gingerbread turned out wonderfully with a light tight crumb. I also remembered that when I made gingerbread house batter, the soda was added into a hot liquid mixture before adding it to the flour (this batter made very solid sturdy walls). I said to myself “There is a question for Joe Pastry here!” Then here you have your post on Baking Soda today! What timing!

    Is the mixing of the baking soda with a hot liquid a gingerbread thing having to do with the molasses or spices? Or is there some other reason that the soda is used in this way?

    Thanks Joe!
    Eva

    1. Hi Eva!

      I’ve seen recipe like this. You usually find that technique in situations where there isn’t much liquid in the recipe, rather a good deal of fat and molasses. My belief is that it’s done this way to ensure that the soda dissolves and then distributes evenly.

      Thanks, Eva. And you’re right — it is a great question!

      – Joe

    2. Hello Eva,

      Any chance you would share that gingerbread recipe here? I used to have one like it that descended to me from my great aunt via my grandmother’s recipe boxes, but search as I might, it now seems to be lost. It was my favorite. It had that light, tight crumb like you said, and I haven’t been able to find one since that gives the same results.

  2. Agree with Eva, what a timely post.
    Last weekend I made my fruit cake (Christmas Cake). My favourite cake is the Eagle Brand milk/mincemeat recipe. My problem is that now with our smaller family, I like making the cake in smaller portions instead of loaf pans. I have a pan that makes 6 small (3/4c) present-shaped cakes – about 2x a muffin cup size. I also have 2 larger shaped pans that hold about 1.5c each. My problem is that the recipe makes too much for these pans and I’d prefer having more smaller cakes to give away.
    The recipe uses baking soda only. So, how can I hold half of the batter somehow to bake 12 small cakes instead of 6 small ones and 2+ larger ones? Do I use baking powder instead of soda (1 for 1)? Is it better to mix dry and wet separately and then split each in half before making the batter? Advice please (maybe for next year at this point).
    PS I really enjoy the technical aspects of your blog 🙂

    1. Hey Cathy!

      Thanks for the kind words! I haven;t seen the recipe, but if you’re concerned that you’ll lose your leavening reaction in half the batter while the other half bakes, I wouldn’t be too worried. Fruitcake recipes are quite thick, so the bubbles that the soda produces will likely stay put while the first batch bakers. Just don’t knock it around too much and try to be as gently as possible when you’re panning the batter for the second bake. Everything should work out just fine!

      Cheers,

      – Joe

  3. Cathy, for a non-chemical solution, you might consider buying a bunch of those nice-looking small paper cases and baking right in them, solving both your timing and your packaging problems at the same time. Just an idea — I promise I have no shares in the disposable baking tin industry.

  4. I have a similar gingerbread recipe to Eva’s, except that mine does not call for lemon juice. It comes from an old Sunset Magazine cookbook. I believe the acidity in the molasses helps the reaction, along with the hot water.

    One other way that my recipe differs from Eva’s is that, once the baking soda is added to the hot water, it is added all at once to the sugar, oil molasses and seasonings, then the flour is added all at once, and stirred till the lumps disappear, then the eggs are beaten in in the last step.

    Over the years, I have found this cake is lighter if it is mixed by hand with a whisk, rather than with an electric mixer.

    Since the whole baking soda/boiling water thing is a bit of a pest, and tends to be a mite unpredictable, I have sometimes wondered how I would go about converting this recipe to a more stable leavener like baking powder, but part of me has always said, usually while my mouth was stuffed with rich, moist gingerbread, “If it ain’t broke . . “

  5. YOUR SITE IS VERY KNOWLEDGEABLE, SO GLAD I FOUND IT, I HAVE A SIMILAR PROBLEM, BUT IT IS WITH MAKING CAKES, MY RECIPE CALLS FOR 1 CUP OF SOUR CREAM AND 4 TEASPOONS OF BAKING SODA, SOMETIMES I HAVE TO MAKE THIS CAKE IN A BIGGER PAN, WHICH CALLS FOR ME TO MAKE TWO BATCHES, WHEN I ATTEMPT TO DO THIS THE BIGGER CAKES DO NOT COME OUT AS GOOD AS THE SMALLER SIZE CAKES, HELP PLEASE, THE FAMILY LOVES THIS YELLOW CAKE RECIPE. THE BATTER THAT IS ALREADY IN THE CAKE PAN IS BUBBLING, WHEN I ATTEMPT TO POUR THE SECOND BATCH OF MIX IN THE PAN, PLEASE HELP!!!!!!!!!!!!!!.

    1. Holy cow! Four teaspoons of soda?? How much cake does this make?

      I ask because that’s a whole lot of leavening power. 4 teaspoons of soda is enough for a dozen loaves of tea bread, for example. I have no trouble understanding why the cake might be bubbling over. Give me the proportions if you can and we’ll get this worked out.

      – Joe

  6. Thanks so much for pointing out the unreacted soda problem. I made biscuits using Bakewell Cream and, while they rose beautifully, they had a weird taste. I thought “metallic” but maybe “soapy” is more appropriate. I’m going to make them again with a little less baking soda to see what happens. Leavening can be a bit tricky here in the mile high city (Denver, CO).

    1. Hey there Holly!

      Yes it’s an awful flavor. You should be in a good position to cut the soda a bit since you’re at such a high altitude. Let me know how it goes!

      Cheers,

      – Joe

      1. I ended up cutting the baking soda in half, which turned out not so great for “Bakewell Cream” biscuits but perfect for cream scones. The stiff biscuit dough didn’t rise well but the looser batter of the scone recipe rose really nicely. Neither had that awful taste, so my mission was accomplished. Thanks.

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