Zenzai (ぜんざい) is a traditional Japanese dessert soup made with azuki beans. This sweet azuki beans soup is served hot with mochi (rice cake) or shiratama dango (glutinous rice flour dumplings) inside the soup. Slightly sweet and with a gentle fragrance from the red beans, it instantly warms up the soul. The toasty, chewy mochi makes everything even better!
This dish brings many cozy memories of my childhood, and I can’t resist zenzai whenever it’s offered. Although it’s a wintertime dessert, I crave and enjoy making it all year round, especially in the cooler climate I live in. With a pressure cooker or ready-to-use red bean paste, we can make this Zenzai recipe in no time!
What is Zenzai?
Zenzai (ぜんざい, 善哉) is a traditional Japanese dessert soup made with sweet red bean paste called anko (餡子), sugar, and salt. You might have heard of a different name—oshiruko (お汁粉) or shiruko—for this dessert or one that’s very similar. Let’s talk about that first.
Zenzai vs. Oshiruko
What‘s the difference between zenzai and oshiruko? It depends on the area of Japan! Since my mom is originally from Osaka, I grew up following the Kansai way.
In the Kansai region (Osaka area):
- Oshiruko is smooth red bean soup without whole beans.
- Zenzai is chunky red bean soup with whole beans.
In the Kanto region (Tokyo area):
- Oshiruko is any red bean soup, either the smooth or chunky type.
- Zenzai is not a soup; it’s dry mochi served with chunky red bean paste.
Another difference is that oshiruko is served with shiratama (glutinous rice) dumplings, while zenzai uses toasted mochi.
Ingredients You’ll Need for Zenzai
- dried azuki/adzuki beans OR prepared sweet red bean paste (anko)
- water
- salt – just a pinch Diamond Crystal kosher salt
- sugar – skip if using store-bought anko, which tends to be sweeter than the homemade version
- kirimochi (Japanese rice cake) – cut the dried mochi in half or quarters, then heat in the toaster oven until puffed and browned.
How to Make Zenzai: 3 Easy Ways
Method 1: Use a Pressure Cooker
Use the Instant Pot to make delicious red bean soup from dried azuki beans in exactly one hour! I love both my Instant Pots (I have this and this) and use the pressure cooking function to cut down on my time in the kitchen. It’s been a lifesaver! Simply cook the rinsed azuki beans and the measured amount of water under high pressure for 15 minutes, stir in the sugar and salt, and cook on low heat to dissolve.
Method 2: Cook in a Pot over a Stovetop
Don’t have a pressure cooker? You can make it the traditional way. Add rinsed beans to a pot with water and bring it to a boil. Then, simmer over low heat for 1–1.5 hours. When you can easily mash a bean with your fingers, add the sugar and salt. Stir to dissolve the sugar, then keep the mixture warm as you prepare the mochi.
Method 3: Use Store-Bought Red Bean Paste
There’s an even a easier and faster way to make zenzai. Use store-bought red bean paste! To a small saucepan, add the anko and water. Bring it to a boil, add a pinch of salt, and mix well. Adjust the consistency by adding water or reducing the soup.
If you end up making a big batch of the homemade version of red bean paste, you can freeze portions to enjoy anytime in Zenzai or various Japanese sweets like Dorayaki, Daifuku, or Dango.
Enjoy Zenzai on January 11 (Kagami Biraki)
Every year, January 11th is Kagami Biraki (鏡開き) in Japan. It is a traditional Japanese ceremony to break the ornamental mochi into pieces and eat it for good health and fortune for the New Year. You can read more about this cultural ceremony and tradition in my Kagami Biraki post.
There is one thing that you must remember for this ceremony: Never “cut” the mochi. It’s a sign of bad luck because it’s reminiscent of seppuku (切腹), or ritual disembowelment during the old times. Therefore, you must break the mochi with a wooden hammer or your hands. We then toast the broken pieces until nicely brown and add them to zenzai to enjoy!
Wish to learn more about Japanese cooking? Sign up for our free newsletter to receive cooking tips & recipe updates! And stay in touch with me on Facebook, Pinterest, YouTube, and Instagram.
Zenzai (Sweet Red Bean Soup with Mochi)
Ingredients
Using Dried Azuki Beans (4–6 servings)
- 1 cup azuki beans (7 oz; click the Metric button above for weights)
- 4 cups water
- 1 pinch Diamond Crystal kosher salt
- ¾–1 cup sugar
Using Prepared Red Bean Paste (1 serving)
- ½ cup sweet red bean paste (anko) (3.5 oz; use tsubuan for a chunky texture; store bought or homemade using my stovetop or pressure cooker anko recipes)
- ½ cup water (add more, to your preference)
- 1 pinch Diamond Crystal kosher salt (to taste)
To Serve
- 4 pieces Japanese rice cake (kiri mochi) (dried, fresh, or frozen; buy kirimochi or make my Homemade Mochi recipe; you can substitute Shiratama Dango)
Instructions
To Make the Zenzai with Dried Azuki Beans (for 4–6 bowls)
- Gather all the ingredients.
Option 1: Pressure Cooker Method
- Rinse 1 cup azuki beans carefully until the water runs clear. Discard any damaged beans that are floating. Drain the water and transfer the beans to a pressure cooker (I use an Instant Pot).
- Add 4 cups water. Cover and lock the lid. Make sure the steam release handle points at Sealing and not Venting.
- Turn on your pressure cooker. For an Instant Pot, select Manual or Pressure Cooker mode, choose High pressure, and set the cooking time to 15 minutes (or 10 minutes for slightly firmer beans).
- For a stovetop pressure cooker, cook on high heat until it reaches high pressure. Then, reduce the heat to low to maintain the pressure for 15 minutes.
- When it’s done cooking, the Instant Pot will switch automatically to the Keep Warm mode. (For a stovetop pressure cooker, remove the pot from the heat.) Let the pressure release naturally for 30 minutes. Then, turn the steam release handle to Venting to release any remaining pressure. Open the lid.
- Add 1 pinch Diamond Crystal kosher salt (to taste) and ¾–1 cup sugar into the pot.
- Cook on low heat (select the Sauté function on the Instant Pot) for about 5 minutes, stirring occasionally, until the sugar dissolves completely.
- After cooking for 5 minutes, the soup will be a bit darker in color. Keep it warm while you prepare the mochi (see below for instructions).
Option 2: Stovetop Method
- Rinse 1 cup azuki beans carefully until the water is clear. Discard any damaged beans that are floating, then drain the water.
- Put the azuki beans and 4 cups water in a pot.
- Bring the water to a boil over medium-high heat. Once boiling, put an otoshibuta (drop lid) on top of the beans. Turn down the heat to medium low and keep it simmering, without the pot lid, for the next 1–1½ hours. Tip: The otoshibuta will prevent the beans from dancing around too much. You can make your own with aluminum foil.
- Some liquid will evaporate, so add water as needed to keep the beans submerged. After 1 hour, pick up a bean and mash it with your fingers. If it mashes easily, it‘s done. Otherwise, cook for another 15 minutes and check again. Add ¾–1 cup sugar and 1 pinch Diamond Crystal kosher salt (to taste) and cook over low heat, stirring occasionally, until the sugar dissolves completely. Keep it warm while you prepare the mochi (see below for instructions).
To Make the Zenzai with Prepared Red Bean Paste (for 1 bowl)
- To a small saucepan, add ½ cup sweet red bean paste (anko) that‘s either store bought or homemade. I used tsubuan (chunky paste) here, but you can use koshian (fine paste) if you prefer. Add ½ cup water. Bring it to a boil. Add 1 pinch Diamond Crystal kosher salt to taste and mix well. Adjust the consistency by adding water or reducing the soup. Keep warm while you prepare the mochi (see the next step).
To Prepare the Mochi
- To make bite-size pieces of kirimochi, cut 4 pieces Japanese rice cake (kiri mochi) into halves or quarters. Put the pieces on a wire rack set in a baking sheet, then place in a toaster oven or regular oven. You can also toast in a frying pan. If using fresh homemade mochi or shiratama dango, add it to the soup to warm it up. If using frozen mochi, heat it in a pot of boiling water until soft.
- Toast the dried mochi until puffed up and nicely brown, about 10–12 minutes.
To Serve
- Serve the red bean soup in individual bowls and add the toasted, fresh, or boiled mochi. Enjoy!
To Store
- Transfer the soup to an airtight container and store in the refrigerator for up to 4 days and in the freezer for up to a month. Prepare the mochi right before you serve the Zenzai.
Nutrition
Did you make this recipe?
Tag @justonecookbook on Instagram so we can see your delicious creation!
Editor’s Note: This post was originally published on Mar 12, 2012. It’s been updated with new images and additional pressure cooking method in the recipe in January 2020.