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I'm in a place where buying baking soda is proving to be quite difficult*, so I was looking for substitutions, and it seems there really aren't any. So this got me thinking: Baking soda is made (or otherwise harvested from nature) in some way.

How can I do this?

I realize the answer is likely to be so involved or expensive that I won't want to undertake the project, but for the determined baker, how would it be done?

*I eventually found some.

NOTE: The question is about making, not sourcing or substituting, baking soda.

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    It is a dread place where one can find Internet access but no bicarb. Practically speaking, if leavening is what you seek, are you willing to consider other leavening alternatives, such as yeast or eggs? If I were in such a situation, I would go with sourdough, or unleavened breads.
    – hoc_age
    Feb 13, 2015 at 2:26
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    As it kinda sucks to make baking soda, you might want to ask about alternatives, specifically naming what it is that you're trying to make. (eg, eggwhite foams work for pancakes, but not denser breads)
    – Joe
    Feb 13, 2015 at 2:52
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    One hint: sometimes it's placed not with baking ingredients, but with cleaning stuff... Just make sure that you get pure baking soda and not a cleaner that contains part BS.
    – Stephie ♦
    Feb 13, 2015 at 5:29
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    @PeterJ: I would recommend caution. pH Up is also often sodium carbonate -- washing soda, Na2CO3 -- which is what baking soda -- NaHCO3 -- turns into when you heat it. It won't harm you, but it won't make your bread rise either. NaHCO3 is more commonly used as a pH buffer than a pH increaser as the H in there can cause it to act like an acid in certain circumstances. pH Up is also sometimes sodium hydroxide -- NaOH -- which you really do not want to put in your bread.
    – Eric Lippert
    Feb 13, 2015 at 6:45
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    As @ChrisH notes, pure baking soda keeps indefinitely in a sealed container at room temperature. If you decide to bring a large supply of baking soda back with you the next time you go abroad, be sure to pack it in ziploc bags for moisture protection, and for maximum amusement of customs officials. ;-)
    – Ilmari Karonen
    Feb 13, 2015 at 13:24

4 Answers 4

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If you really want to do some chemistry, the next questions are:

  1. What can you get?
  2. Do you know how to handle these safely?

If you have a solution of carbonic acid (H2CO3) you can slowly mix in sodium hydroxide (NaOH - in a solution, not a powder!) until the pH is around 10.3, then you'll have a solution of NaHCO3. Or you could do the same thing by bubbling CO2 through a solution of NaOH.

You'll then need to dry or concentrate it without heating, or the NaHCO3 will break down (just like it would when baking).

Or you could start with sodium carbonate and add hydrochloric acid, but that would give you equal parts of baking soda and table salt in water, not sure how easy they would be to separate.

Keep in mind that sodium hydroxide will dissolve any flesh that it touches, and hydrochloric acid will do the same, plus it evaporates.

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    Although the above stuff is possible, I really don't think you should do any of that. Any place where you can do what I've described, you should also be able to find a pharmacy that will sell you some form of bicarbonate.
    – Pepi
    Feb 18, 2015 at 17:22
  • Also note that these methods require starting with a checmical that can substitute for baking soda! At least, I assume that the only reason we use baking soda instead of lye is that it's so much harder to kill yourself with it.
    – octern
    Jun 29, 2015 at 4:59
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Sodium bicarbonate, the chemical name of baking soda, has always been manufactured using industrial processes at an industrial scale. I can't see how it could be practical to make at home. You'd need specialized equipment and you might well find that the materials you need aren't any easier to acquire.

Baking soda is known by different names, in addition to sodium bicarbonate according to Wikipedia it's also known as bread soda, cooking soda, and bicarbonate of soda. So it's possible it's available in your area on under one of these other names. If you live in area where a language other than English is used then you might find other alternative names in that language's version of the Wikipedia page. If you still can't find any you'll either have to pay to have it shipped to you or find a substitute recipe that uses some other leavening agent.

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    The OP has clarified that the question is not at all about sourcing, so the second half of your answer may not be helpful here. I've posted another question where it'd fit right in though: cooking.stackexchange.com/q/54883/1672
    – Cascabel ♦
    Feb 18, 2015 at 19:04
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    @CascabelI think if the second part of my answer isn't relevant, despite it not being what the original poster wants to hear, then the question is likely off-topic here. If he wants to know how to make food grade baking soda at home, regardless of cost, risk and zoning laws, it's something he should be asking the chemistry experts at chemistry.stackexchange.com
    – Ross Ridge
    Feb 18, 2015 at 19:31
  • I'd say it's probably still on topic here, even if it might get better answers on chemistry.stackexchange.com, and even if the answer is "you can't really do it at home". Certainly true that the OP might be interested in posting there though.
    – Cascabel ♦
    Feb 18, 2015 at 19:35
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If you can get sodium hydroxide, you can make baking soda. The stuff absorbs CO2 from the air along with water to produce NaHCO3, baking soda. I've had batches of commercial NaOH that were in fact up to 40% NaHCO3.

Best way to do it is to dissolve your NaOH in water, and just let it stir a few weeks. It'll suck CO2 out of the air. When the pH gets down to 6.5 or 7, you'll have reasonably pure baking soda. Evaporate the water and you're done. Be aware that heating baking soda in an oven at over 200°F will give you sodium carbonate rather than baking soda, so evaporate gently.

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  • What do you mean by "let stir a few weeks"?
    – Flimzy
    Oct 6, 2015 at 20:04
  • @Flimzy, it's got to absorb carbon dioxide out of the air. That's only present at about 0.3%, so getting enough in takes a while. Stirring is quite effective at speeding up exchange between air and liquid phases.
    – Wayfaring Stranger
    Oct 6, 2015 at 20:27
  • @Flimzy: You're right. Making NaOH is an icky process: en.wikipedia.org/wiki/Chloralkali_process. The wood-ash process gives KOH, which is NOT what you want for baking. I've removed the link. You'll just have to find NaOH, if you want to go this route. Some hardware stores sell it labelled as "Red Devil Lye".
    – Wayfaring Stranger
    Oct 6, 2015 at 20:33
  • @WayfaringStranger: And that's where you're wrong. Making arbitrarily-pure soda lye (NaOH) requires only arbitraily-pure sodium carbonate (Na2CO3), using all the same steps as the wood-ash process. Wood contains more potassium than sodium, so its post-burning carbonate-ash is potassium-based; saltworts such as barilla (Salsola soda) or seaweeds such as kelp are more rich in sodium, so their ashes likewise.
    – Jacob Stai
    Aug 23, 2017 at 6:50
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If I'm understanding this right, lye dissolved in water and let sit to absorb carbon dioxide from the air will turn into sodium hydroxide. If you then gently evaporate the water (at low temperatures) the residue left will be baking soda.

My understanding is that back when everything (more or less) was made at home, lye was made from wood ash, so if my understanding is correct, this should be a way to make baking soda without resort to a pharmacist.

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  • This would be a good answer with references.
    – Flimzy
    Feb 18, 2017 at 9:00
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    Lye already is sodium hydroxide.
    – Cascabel ♦
    Apr 17, 2017 at 15:27

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