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I have food grade lye (sodium hydroxide) from pretzel making and I want to make chewy noodles, either ramen or Chinese noodles. Many of these recipes call for lye water or kansui.

I have found many resources about making your own kansui from baking soda (for example Can I substitute baking soda for kansui powder?), but none that start with lye.

I've found that kansui has a pH of about 12.6 and sodium hydroxide (NaOH) has a pH of 14. Using a pH calculator, I should get a pH of 12.6 with 0.04 moles of NaOH in 1 liter of solute (water). That's 1.5 grams per liter. (It has been a while since high school chemistry so please jump in here if I'm making a massive mistake)

Is this a valid approach to making lye water or kansui? What might I be overlooking?

Anastasia Zendaya
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  • Your calculations look about correct - however, remember that some of the OH- will be used up in the reaction when making the kansui, so at 0.04 mol/l you will probably deplete this quite rapidly, meaning that the pH will rise rapidly and not end up with the effect you want. – bob1 Mar 23 '21 at 02:04

1 Answers1

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80% potassium carbonate, 20% sodium bicarbonate at some concentration https://omnivorescookbook.com/kansui is likely to behave very differently than your sodium hydroxide. Kansui is probably strongly buffered, while your pH is likely to wander. That sort of thing is liable to wreck recipes. I'd find a good how-to online, and make the stuff right.

Wayfaring Stranger
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