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I see this recipe for ramen noodles ("alkaline noodles") that says to use bicarb / baking soda that is baked in a very slow oven for an hour (250F / 120C) before incorporating into the noodle dough. Is it necessary to bake the bicarb? What does baking do?

The New York Times has an article about baked baking soda, which says that baking transforms the sodium bicarbonate into sodium carbonate (NaHCO3 into Na2CO3?) but this seems strange; does this really work or is it safe? Am I creating hydrogen gas or presumably harmless water vapor and carbon dioxide?

If it is worth doing for some reason, then there are the ancillary questions. How do I know when it's "done" baking? Both seem to be nondescript white powders. Will a different compound result, after dissolving both in water? Are there any safety concerns with sodium carbonate?

hoc_age
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  • Water vapor and carbon dioxide - no free hydrogen. – Ecnerwal Nov 10 '15 at 12:46
  • FYI, I came to this question after watching [Pastry Chef Attempts to Make Gourmet Instant Ramen](https://www.youtube.com/watch?v=g1GFJxVeH9c) – spraff Nov 30 '18 at 20:43

2 Answers2

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Baking turns bicarbonate of soda into a weak form of lye - sodium carbonate, as you said. It basically makes it a stronger alkali. The actual baking process is safe, but the resulting lye is an irritant and you should avoid getting in on your skin, and definitely avoid it getting it in your eyes.

The difference in texture and colour is noticeable after baking. The texture will be finer, and it will be whiter.

ElendilTheTall
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  • Just as simple as that... eh? Just seems not obvious that such a chemical change could happen just by lightly toasting. I baked a batch of the stuff, and it looked a little "pocked" but not different enough to seem "done". Perhaps I shall simply have to make two batches and see if they're different. Also seems that the two things would be the same after they dissolve... but I guess I need to brush up my grade-school chemistry! – hoc_age Nov 08 '15 at 21:45
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    Baking it removes the water. Here's a good breakdown: http://www.curiouscook.com/site/2010/09/achieving-a-distinct-flavor-without-going-to-extremes.html – ElendilTheTall Nov 08 '15 at 21:49
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    @hoc_age "Thermal decomposition", most compounds break down into simpler compounds, and eventually into base elements when heated, is just a matter of the right amount of heat. Baking soda breaks down at 120°C, the base material for common cement breaks down at 600°C , some fun chemical like Sodium nitrate generate so much heat once a small amount is heated that it chain reacts, hence it's use in explosives – TFD Nov 08 '15 at 22:35
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    Sodium carbonate isn't a form of lye: lye is sodium hydroxide. – David Richerby Nov 09 '15 at 00:35
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    Sodium carbonate is washing soda. It's a bit more alkaline than baking soda, but not nearly as strong as less. – SourDoh Nov 09 '15 at 03:54
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    @hoc_age yep it's that simple. And in fact it does it on its own over time. That's why there is a space for you to mark the date when you opened your box or can of baking soda and baking powder, because it does transform into a different chemical over time. Baking just speeds it up. – Escoce Nov 09 '15 at 16:11
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    Also, the amount of hydrogen released is minimal. And, hydrogen wants to escape so badly that even if you had a canister of it releasing into the oven, it will get past the seal faster than the oven could reach combustible levels of hydrogen. It escapes from earths gravity at the rate of 50ft per second at sea level. – Escoce Nov 09 '15 at 16:13
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    NaHCO3+heat -> Na2CO3 (and H20, CO2) but Na2CO3 ≠ NaOH – Ecnerwal Nov 10 '15 at 01:41
  • Used to be able to buy sodium carbonate pretty easily. It's a useful cleaner. Now that it's gotten scarce we have to synthesize it ourselves in an oven. Just pour out a whole box of bicarbonate onto a cookie sheet, cook as described and let cool. Put it in a old Mayonnaise jar or some-such, and you'll have it whenever you need it. The stuff is pretty stable. – Wayfaring Stranger Mar 03 '19 at 03:22
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True ramen noodles are made with alkaline/base ph ingredients so they will have a specific, distinctive texture, color & flavor, so yes, using the alkali makes a difference. Serious Eats recently published a home-made noodle recipe that covers these points and a lot more, plus gives a method for creating the sodium carbonate from bicarb that uses accurate weighing & timing to tell when the conversion is finished. It updates McGee's earlier method, improving it for home cooks. The Harold McGee's NYT piece does have a lot more background info on the chemistry so it's a useful read, too.

As other answers have noted, making it in your home oven is very safe, but care must be used when handling the finished substance. It's not too strong a base so the main risk is overdrying/irritating skin (on this list from Sciencing it'd be between Bicarb & Borax in intensity) so minimizing contact is sufficient for most people. If your lungs are especially sensitive (ie if you have COPD or Asthma) it's prudent to avoid being around irritating gases or powders or to use a breathing mask. And, when working with liquid forms I always wear eye covering in case of splashes.

For those who're a bit rusty since their high-school chemistry class days, these articles cover general home chemical safety tips in more detail, listed from least to most detailed:

Eileen
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