Step 1

Rinse and drain the beans. Transfer the beans to the bowl of an Instant Pot. Add the water, seal the Instant Pot with the lid, and cook the beans on High Pressure for 22 minutes.

Step 2

Once the cooking stops, let the beans sit for another 25 minutes so they can soften further. Release any residual pressure by moving the pressure release to “Venting.” Drain the beans.

Step 3

Transfer the cooked beans to a food processor to blend until smooth. Because there isn’t enough liquid in the beans, they won’t mix properly in a high-speed blender.

Step 4

Once you blend the beans, I recommend pressing the puree through a mesh strainer to strain out some of the tougher skins of the azuki beans. Straining isn’t absolutely necessary but highly recommended if you want a smoother paste. You can strain the puree twice if you like.

Step 5

Heat a large nonstick sauté pan over medium heat. Use a nonstick pan or else things can get messy (see note 5). Add the walnut oil and swirl to coat the pan with the oil. Add the pureed beans and cook for 3 minutes, stirring frequently.

Step 6

Add the sugar to the pan and stir to combine with the beans. If you're using kansui, add it now, too. Reduce the heat to medium-low and continue cooking and the paste for another 10 to 12 minutes. Eventually, the paste will thicken so much that you can fold up the paste with a flat spatula. The consistency of the paste will almost be like soft play-doh. Reduce the heat to low.

Step 7

Take a pea-sized portion of the paste and let it cool for 30 seconds before tasting. Add more sugar, if desired.

Step 8

Add the coconut oil to the pan. Use a flat spatula to fold the oil into the paste. Turn off the heat.

Step 9

Transfer the paste to a mixing bowl and let cool for 20 minutes before using. The red bean paste crusts easily, so cover the bowl with a damp towel.

Step 10

Refrigerate any unused red bean paste for up to a week. You can also freeze the paste in a freezer bag or container and use it within a few months.