Sweet anko (red bean) paste
What you will need
200g azuki beans
Water as needed
How to cook
Wash and sort your beans. Add enough water to cover by at least 2 inches. Set aside to soak for at least 8 hours.
Strain the beans and rinse them well.
Transfer the beans back to a pot and add enough water to cover. Bring to a boil.
Once the water comes to a boil, strain the beans once more.
Simmer for 1 hour
Return the beans to the pot. Add water to cover, and bring to a simmer. Simmer the beans for 1 hour, adding water every so often to keep the beans completely submerged.
Stir in the sugar
When the beans are cooked through and tender, stir in the sugar.
Simmer until thickened
Continue to simmer until the liquid begins to thicken, stirring often. Stop when you can draw a line through the beans with your spoon, and the line remains visible for a couple of seconds. Stir in a pinch of salt and chill.
Mash to make tsubushian
Mash roughly with a potato masher or a wooden spoon to make tsubushian (mashed red bean paste). I actually used a mason jar to mash mine.
Sieve to make koshian
For an even more refined paste, press through a sieve.