Mochi Red Bean (Recipe)
Sweet Red Bean Paste (Koshian) is a staple in many Japanese desserts and snacks, cherished for its velvety texture and balanced sweetness. This delicate paste, made from azuki beans, is often used as a filling in mochi, dorayaki, and taiyaki, or simply enjoyed on its own.
The subtle sweetness and earthy flavor of the azuki beans make Koshian a delightful treat for those who love traditional Japanese sweets. This recipe will guide you through making your own homemade Koshian, perfect for filling soft mochi dough, which we'll also show you how to prepare.
Sweet Red Bean Paste (Koshian)
Ingredients
7 oz (200 g) azuki beans
Water
1 cup (200 g) sugar
½ tsp Diamond Crystal kosher salt
Instructions
Rinse the azuki beans thoroughly, discarding any broken beans. Drain well.
Transfer the beans to a large pot and cover with enough water to submerge the beans by 1–2 inches.
Bring the water to a boil over medium-high heat. Once boiling, drain the beans in a fine-mesh sieve.
Return the beans to the pot, add fresh water (again covering the beans by 1–2 inches), and bring it to a boil over medium-high heat. Lower the heat to medium-low and let it simmer for 1–1½ hours.
Check the beans after 1 hour by mashing one between your fingers. If they mash easily, they're done. If not, continue simmering, adding water as needed.
Reserve some cooking liquid, then drain the beans again.
Transfer the beans to a food processor and process until smooth, adding 1–2 tablespoons of the reserved cooking liquid if necessary to achieve a smooth paste.
Return the smooth paste to the pot over medium-low heat. Stir in half the sugar, mixing constantly to avoid sticking.
Once the sugar has dissolved, add the remaining sugar and the salt. Continue stirring until the paste thickens and you can draw a line at the bottom of the pot with your spatula.
Turn off the heat and transfer the paste to a flat baking sheet to cool. The paste will thicken further as it cools.
Mochi Dough
Ingredients
¾ cup (115 g) mochiko flour
¾ cup (177 g) water
¼ cup (50 g) sugar
Cornstarch (for dusting)
Instructions
In a medium bowl, whisk together the mochiko flour and sugar.
Gradually add the water, whisking until the mixture is completely smooth.
Cover the bowl loosely with plastic wrap and microwave on high for 1 minute.
Stir the dough with a wet rubber spatula, cover again, and microwave for another minute.
Stir once more, cover, and microwave for 30 seconds. The dough should be translucent at this point.
Dust parchment paper with cornstarch, and pour the mochi dough onto it. Sprinkle more cornstarch on top to prevent sticking.
Refrigerate the dough for 15 minutes until firm and easy to handle.
Assembling
Weigh the entire mochi dough and divide the weight by 8 to get equal portions.
Divide the dough into 8 equal pieces, weighing each piece to ensure uniform size. Roll each mochi piece into a ball and set aside.
Flatten a mochi ball gently using your hands, creating a round disc large enough to encase the red bean filling. Dust your hands with cornstarch to prevent sticking.
Take the cooled red bean paste and form 8 pieces in a ball shape, making sure each portion weighs the same as one mochi ball.
Place a red bean filling ball in the center of the mochi disc.
Carefully pinch the edges of the mochi dough together around the filling, sealing it completely by pinching the top closed.
Gently roll the filled mochi ball in your hands to create a smooth, round shape.
Dust each completed mochi with additional cornstarch if needed, and wrap them in plastic wrap to prevent drying out.
Repeat this process for all 8 mochi balls.
Tips & Tricks
Be careful not to overcook the azuki beans. They should be soft enough to mash easily but not overly mushy.
When processing the azuki beans, add the cooking liquid gradually to prevent the paste from becoming too watery.
Make sure to stir the red bean paste constantly while cooking to prevent it from burning or sticking to the pot.
Dust your hands and tools generously with cornstarch when handling the mochi dough to avoid sticking.
To add a fun twist, consider adding food coloring or a bit of matcha powder to the mochi dough for variety.
Notes
If you don't have a food processor, you can mash the azuki beans by hand using a fine-mesh sieve or potato masher, though this will take more time.
You can freeze any leftover red bean paste for up to a month, making it easy to use in future desserts.
For a smoother texture, strain the bean paste through a sieve before returning it to the pot to remove any remaining skins.
Chewy Mochi Red Bean!
Making Sweet Red Bean Paste (Koshian) and chewy mochi dough from scratch may seem intimidating, but the results are truly rewarding. The combination of the subtly sweet, creamy paste with the soft, chewy mochi creates an irresistible treat that’s perfect for anyone with a love for Japanese desserts. Plus, with homemade koshian, you have full control over the sweetness and texture, allowing you to customize it to your liking. Whether you enjoy your mochi plain, filled, or as part of a larger dessert, this recipe will give you the tools to explore traditional Japanese flavors in your own kitchen.