Kansui is the alkaline water that gives ramen noodles their distinctive texture. Added to wheat-flour dough, it makes the noodles firmer, springier, and more resilient than ordinary wheat noodles, while also contributing to their characteristic yellowish color and subtle alkaline aroma.
Kansui is generally made with alkaline mineral salts, especially sodium carbonate and potassium carbonate, dissolved in water. The alkaline environment changes the behavior of the flour’s proteins and starches, helping ramen noodles retain their bite during cooking and in hot broth. It can also affect how the noodles absorb soup.
The name comes from the Chinese term jian shui, meaning alkaline water. Ramen developed from Chinese-style wheat noodles, and the use of alkaline water remains one of the key features distinguishing ramen noodles from wheat noodles such as udon. Some modern recipes use powdered kansui or baked baking soda as a substitute.
The other options describe different ramen components: shoyu is soy sauce, dashi is a stock, and mizu simply means water. They may appear in a ramen recipe, but they do not create the noodles’ signature elasticity.