Gather all the ingredients.
The ratio of azuki beans to water is 1:4 (300 grams azuki beans = 1200 grams/ml water).
To make Koshian (fine), you will need the same weight of sugar and azuki beans (300 grams azuki beans : 300 grams sugar).
To make Tsubuan (chunky), you will need about 80% of sugar compared to Koshian (300 grams azuki beans : 240 grams sugar).
For Koshian (fine red bean paste), you will stop cooking the azuki beans earlier than when you cook for Tsubuan (coaster red bean paste), this is because you will need some liquid in order to properly mix the azuki beans with the food processor.
If you put hot liquid in the food processor or blender, as it purees, the liquid may start coming out the edges of the food processor or the built up steam can actually blow the lid off the blender. To prevent this from happening, it’s best to let the liquid cool for a few minutes before pureeing, fill the food processor or blender up only half way, work in batches and hold a towel over the lid when pureeing.
Recipe by Namiko Chen of Just One Cookbook. All images and content on this site are copyright protected. Please do not use my images without my permission. If you’d like to share this recipe on your site, please re-write the recipe in your own words and link to this post as the original source. Thank you.