Ramen noodles are wheat noodles made with alkaline water (kansui — a solution of potassium carbonate and sodium carbonate, or baked baking soda as a substitute) that gives them their characteristic yellow colour, their firm, springy texture, and their specific slightly alkaline flavour that distinguishes them from all other noodles. The alkaline environment of the kansui-treated dough changes the gluten network's chemical structure — producing a more elastic, bouncier noodle that retains its texture in hot broth longer than a neutral-pH noodle would.
**Kansui chemistry:** The alkaline water (kansui) raises the dough's pH from the neutral 7 to approximately 8.5–9.5. This alkaline environment: - Reacts with the flavonoid pigments in the wheat flour — turning them from white to a pale yellow (the characteristic ramen noodle colour). This is a pH indicator reaction: the same pigments turn yellow in alkaline environments and remain white in neutral or acid ones. - Changes the gluten protein structure: the disulfide bonds between gluten proteins form differently in alkaline conditions — producing a more elastic, bouncier texture that springs back more completely when stretched. - Creates the specific slightly alkaline, 'mineral' flavour note of ramen noodles — perceptible as a faint, clean alkaline quality different from any other noodle. **Baked baking soda as kansui substitute:** Regular baking soda (NaHCO3) baked at 130°C for 60 minutes converts to sodium carbonate (Na2CO3) — a stronger alkaline compound equivalent to one component of kansui. Use baked baking soda (3% of flour weight) as a practical substitute for professional kansui. **Fresh vs dried:** Fresh ramen noodles (straight from the maker, or refrigerated): used the same day or within 3 days. Their alkaline content is at maximum — the freshest noodle springs back most completely in the broth. Dried ramen noodles: the alkaline content diminishes slowly over the drying time. Still correct ramen noodles, but the bounce and the alkaline flavour note are slightly diminished compared to fresh. **Boiling:** A large volume of actively boiling, unsalted water (ramen noodles are already seasoned by the broth's tare — no additional salt needed during boiling). Fresh noodles: 1–2 minutes. Dried: follow package timing. Drain immediately and add to the bowl.
Tadashi Ono & Harris Salat, *Japanese Soul Food* (2013)