Why are thin ramen noodles harder?

Thin ramen noodles, such as those used in Hakata-style ramen, possess a weak physical structure due to their fineness, making them naturally susceptible to breaking down or becoming soggy.2 To compensate for this structural fragility, the Kansui formulation for thin noodles uses a higher ratio of potassium carbonate.2 This increased hardness reinforces the noodle structure, ensuring that even very fine noodles maintain a desirable bite and resistance to dissolving when served in the rich, hot broth, thereby facilitating the fast-paced dining style required for these thin varieties.