Koshian (Smooth Bean Paste)

Koshian (Smooth Bean Paste)

Koshi An

Kimika Soko Takechi
Larry Sokyo Tiscornia


  • Baby lima beans or azuki (adzuki) beans 454 gm (1 lb)
  • White granulated sugar 250 gm (8.8 oz)


  • Check the beans carefully and discard any that are off color or broken.
  • Remove any small rocks.
  • Rinse the beans in cold water several times and then soak overnight in plenty of cold water to soften.
  • Discard soaking water, rinse and cover beans with fresh cold water.
  • Bring the beans and water to the boil and skim off any foam that forms on the surface.
  • Discard the hot water once it comes to the boil and once again cover with cold water and bring to the boil, continuing to remove any foam that forms. Repeat this process 3 or 4 times.
  • Cover the beans with plenty of fresh cold water and boil until cooked well, usually about 1 to 1 1/2 hours.

  • Remove the pot from the stove and press the cooked beans through a very fine strainer into a clean bowl. NOTE: The strainer can be placed into the bean water, that empties into the bowl, to make separating the skins easier.

  • Discard the skins from the strainer and wash the strainer.
  • Strain the pureed beans and water several times to make it very smooth. Discard any bean residue that remains in the strainer.
  • Pour the pureed beans and liquid into a thin cotton bag.
  • Wring the bag to remove excess liquid. Be careful not to remove too much liquid from the beans. Usually an indentation made by pressing a finger into the beans will hold its shape. If it crumbles, too much water has been removed.
  • Remove the beans from the bag.
  • Place in a heavy pot (enameled cast iron is ideal). Add the sugar and cook over medium heat, mixing constantly with a wooden spoon, until all of the sugar is dissolved.

    The temperature of the beans and sugar should be brought to the point that the mixture begins to bubble or boil. Once it reaches this temperature the heat can be turned down but continue to stir until the proper consistency has been obtained. A back and forth mixing is preferred to circular mixing. The finished bean paste will have a more shinny appearance if done this way.

NOTE: If too much water was removed initially, more hot water can be added while cooking the beans and sugar. If too little water was removed it will be necessary to cook the beans and sugar much longer to remove the excess water. It is important to stir continuously to avoid burning.

  • When ready, place the prepared bean paste on a glass or ceramic plate to cool. If coloring or flavoring is to be added it is easy to do while the bean paste is still in the cooking pot with the heat turned off. Remove a little of the bean paste from the pot and add the color to it. Place the colored bean paste back into the pot, a little at a time, and mix it until the color is evenly distributed.