Home made Tsubushian Paste to yield 340g(12oz)
0.28 lb azuki beans
0.33-0.39 lb sugar
0.01-0.01 lb salt

Rinse azuki and soak in plenty of water for 7 to 8 hours.
2
Discard the soaking water; place the beans in a saucepan with water reaching 3 cm above the surface of the beans.
3
Bring to a boil, then add about 300 ml water, and bring to a boil again.
4
Drain beans of all water (discarding water), return beans to saucepan, cover with plenty of water, just bring to a boil, then lower heat, and cook until tender, stirring occasionally.
5
The beans with burn if the heat is too high, or they are not stirred a little.
6
It should take between 1 and 2 hours for the beans to become tender.
7
When the beans are tender enough to mash easily between your fingers, (not all falling apart) turn off the heat; cover, and let stand 20 minutes.
8
Add enough room temperature water to the beans in the saucepan to cool them.
9
Wait until the beans have sunk to the bottom of the pan, then pour off the clearer liquid on top without disturbing the darker liquid below.
10
Add more water, wait for the beans to sink, and remove the water on top again.
11
After adding and pouring off the top part of the water three times, drain the beans by pouring the contents of the saucepan into a colander or sieve that has been lined with cloth.
12
Return about one half of the cooked beans to the saucepan; add the smaller amount of sugar, and cook, stirring constantly, over high heat, until the sugar has been incorporated.
13
This burns easily, so lower the heat if necessary.
14
Add the remaining cooked beans and continue to cook, while stirring and adding more sugar if necessary, until you have a shiny bean paste.
15
This will thicken as it cools, so it is not necessary to cook the bean paste for a long time at this stage.
16
You can mash some of the beans while you are cooking them with the sugar if necessary, but this type of bean paste should have some beans retaining their original shape.
17
Add the salt at the very last stage of cooking and stirring.
18
Taste to make sure the flavor is right.
19
Remove from heat, spread out on a large plate to cool.

Read more at: http://www.food.com/recipe/tsubushi-an-sweet-bean-...