Akafuku Mochi

1. Rinse the Adzuki beans thoroughly under cold water. Place the rinsed Adzuki beans in a large pot and add enough water to cover them by at least 5 cm. Bring to a boil over high heat, then boil for 5 minutes. Drain the Adzuki beans and discard the water (aku-nuki).

2. Return the blanched Adzuki beans to the pot and add fresh water, again covering them by at least 5 cm. Bring to a boil, then reduce heat to low, cover, and simmer for 1.5 to 2 hours, or until the Adzuki beans are very soft and easily crushed between your fingers. Add more water during simmering if needed to keep the beans submerged.

3. Once the Adzuki beans are soft, drain them, reserving about 100 ml of the cooking liquid. Pass the warm Adzuki beans through a fine-mesh sieve or a food mill to create a smooth paste (koshian). This requires patience to ensure no skins or lumps remain.