Ramen noodles are wheat noodles made distinctive by kansui — an alkaline mineral water of sodium and potassium carbonates worked into the dough — which sets them apart from pasta, udon and every other Western or Japanese noodle. The alkali turns the dough springy and slippery, tints it a natural pale yellow, and gives cooked ramen its signature bouncy, resilient bite and faint mineral tang. Sold fresh, dried in coiled nests or flash-fried as instant blocks, they are the backbone of ramen, the Japanese noodle soup, where their exact thickness, curl and firmness are chosen to match the broth. Plain they smell faintly of warm wheat with an eggy, mineral edge; their real job is to carry and cling to broth while holding a lively chew that soft pasta or udon never quite match.