Kansui
Also known as: alkaline water, lye water, kan sui, kansui
Kansui is an alkaline additive of potassium and sodium carbonates or phosphates that is kneaded into the dough of Chinese noodles and ramen to make them yellow and springy.
Kansui is the alkaline additive without which there are no ramen noodles. Japanese labelling rules define it as an alkaline agent for making Chinese noodles that contains one or more of potassium carbonate, sodium carbonate, sodium hydrogen carbonate, and potassium or sodium salts of phosphoric acid. The collective name kansui may be used on the label.
In the EU these salts are ordinary food additives: E500 is sodium carbonates, E501 potassium carbonates, and phosphates belong to the E338 to E452 group. US Cup Noodles Chicken, for example, lists potassium carbonate, sodium carbonate and sodium tripolyphosphate among its ingredients.
The Japanese labelling code calls wheat flour kneaded with kansui, including the traditional tōaku, Chinese noodles, chūka men. Researchers explain what the alkali does: natural flour flavones turn yellow at alkaline pH, and proteins cross-link more strongly, so the noodles become harder, chewier and more resistant to stretching. Kansui is usually 0.5 to 1.7 % of the flour weight; one recipe uses 1 g of a 9 to 1 sodium and potassium carbonate mix and 1.75 g of salt per 100 g of flour.
Why it matters to you. Yellow, springy noodles are a sign of kansui, not necessarily of egg. Look for the word kansui or E500 and E501 in the ingredients.
Facts
| Raw material | Potassium and sodium carbonates, sodium hydrogen carbonate, potassium and sodium phosphates |
|---|---|
| Legal basis | Japanese additive labelling rules; EU: E500, E501, phosphates E338–E452 |
| Main use | Yellow colour and springiness of Chinese noodles and ramen |
How it connects to Noodles
Kansui → kind of → Wheat noodles → kind of → 🍜 Noodles
Links
- Where it is found
- Ramen, Cup Noodles
- Part of
- How noodles are made, Wheat noodles
Frequently asked questions
Why is kansui called lye water or alkaline water on noodle packs?
It is an alkaline agent for Chinese noodles, and the collective name kansui may stand on the label in place of a list of salts.
Is it true that yellow noodles always contain egg?
No. Kansui gives the yellow colour: flour flavones turn yellow at alkaline pH.
Is kansui one substance or a mixture?
A mixture: potassium and sodium carbonates, sodium hydrogen carbonate and phosphate salts.
What should I look for in the ingredients of ramen in the EU?
Sodium or potassium carbonates, listed by their E numbers, and phosphates.
Why do ramen noodles need kansui?
The alkali makes them yellow and springy, because proteins cross-link more strongly.
Sources
- Consumer Affairs Agency of Japan: additive labelling, list of simplified and collective names (かんすい)
- Commission Regulation (EU) No 1129/2011, Union list of food additives
- Yeoh S. Y. et al. (2023) Alkaline noodles review. npj Science of Food 7: 8
- Japan Fair Trade Council: Fair Competition Code on Labelling of Fresh Noodles (中華めん)
- Open Food Facts: Nissin Cup Noodles Chicken Flavor (0070662030035)