Remove impurities and rotten things from red beans, wash them clean, and strain them through a sieve. Pour enough water into the pot to soak the red beans, then simmer over the heat. Bring to a boil for a while and pour out the boiled water. Put the red beans back in the pot and bring to a boil with about three times the amount of cold water.

Boil the red bean grains until they are crushed if you press them with your hands. If it's boiled but there's still water left, drain it, cover it and let it simmer for about 5 minutes over low heat. Place cold water in a large bowl and pour boiled red beans into it.

Mash the red beans dipped in cold water with your hands. Then put it down on a sieve. Rub the red bean grains down well with your hands, and discard the remaining skin in the sieve.

If you leave the red bean water in the bowl under the sieve for a long time, it will be separated into sediment and clear water. Then carefully pour out the top water and leave only the sediment.

Place the sediment in a pot, add sugar and a moderate amount of salt, and place on medium heat. You can add or subtract the amount of sugar to suit your taste. Keep stirring over medium heat with a wooden spatula, and when it starts to thicken, reduce it to low heat and continue to boil down. If you boil it down while stirring it for a long time, you can feel that the moisture is drained and quite thick. If you scratch the floor with a spatula, the sediment stays there, it's complete. If it's too watery, it's hard to shape the sediment later, so you have to boil it down until it's just right^^

After cooling it down, I put it in a hot sterilized airtight container.

I think it would've been better if it boiled down a bit more. When I tried the finished red bean paste, the salt and sugar seasoning were just right, but when I tried the red bean bread, I thought I should make the filling sweeter