Sweet red bean paste is a common ingredient found in Japanese sweets. It is made by simmering azuki (red beans) in water along with a sweetener such as sugar or honey or maple syrup, etc. You should be able to find sweetened red bean paste in your local Asian grocery store. It can be a little difficult however as it has several different names. Common names include: an, anko and ogura. If that were not enough it can have different names based on the consistency of the red bean paste as follows:
Tsubuan - whole red beans simmered in water with a sweetener
Tsubushian - red beans simmered in water with a sweetener and then mashed
Koshian - red beans simmered in water with a sweetener and then mashed and then sieved for a nice smooth finish
If you cannot find it in stores it is easy enough to make your our. All you need is some azuki (sometimes called adzuki) beans, some water and a sweetener such as sugar. Regular grocery stores near me carry canned azuki beans which are easier to work with. If you can only find dried azuki beans then soak them over night and extend the simmering time until they are nice and tender.
Tsubushian (Japanese Sweetened Red Bean Paste)
1 14 oz can azuki beans
1 cup sugar
1. Rinse the beans.
2. Place the beans and sugar into a sauce pan and cover with an inch of water.
3. Bring to a boil, reduce heat and simmer for about an hour. (The water should just cover the beans by this point.)
Note: At this point you have Tsubuan.
4. (optional) Mash the beans with a potato masher or a fork and add water to bring the paste to the consistency that you want.
Note: I like to just dump them into the food processor and give them a whirl until they are nice and smooth.
Note: At this point you have Tsubushian.
5. (optional) Strain the paste through a sieve to remove the bean husks and make the paste smoother. You may need to add water to the beans to help them through the sieve. If the beans are too liquidy after, simmer them to remove the excess liquid.
Note: At this point you have Koshian.
Recipes that use Tsubushian (Japanese Sweetened Red Bean Paste):
Ichigo (Strawberry) Daifuku
Azuki (Red Bean) Ice Cream