Nothing sounds better than a warm bowl of homemade Zenzai (Oshiruko) or sweet red bean soup with toasted mochi rice cakes! I’ll show you 3 ways to make this popular winter dessert in Japan with either homemade or store-bought ingredients.
Zenzai (ぜんざい) is a traditional Japanese dessert soup made with azuki beans. This sweet red bean soup is served hot with mochi (rice cake) or shiratama dango (glutinous rice flour dumplings) inside the soup.
Slightly sweet, with a gentle fragrance from the red beans, the dessert soup has the instant magic of warming up one’s soul. The toasty, chewy mochi makes everything even better! It is one of those dishes that brings many cozy memories of my childhood. I couldn’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 red bean soup in no time!
What is Zenzai (Oshiruko)?
Zenzai (ぜんざい, 善哉) is basically a soup made from boiling azuki beans with sugar and salt. You might have heard of a different name for this dessert. Oshiruko(お汁粉) or Shiruko is used in the east of Japan where boiled azuki beans are crushed into a smoother paste and become more watery soup than Zenzai.
Quick Review – Zenzai vs. Oshiruko
East of Japan (East of Nagoya, including Tokyo)
- Chunky red bean soup OR soup-less chunky red bean over mochi is called Zenzai.
- Soupy red bean soup without any beans is called Oshiruko.
West of Japan (West of Nagoya, including Osaka)
- Both chunky and fine red bean soups are called Zenzai.
3 Super Easy Ways to Make Zenzai (Oshiruko)
Method 1: Use a Pressure Cooker
If you have a pressure cooker, you can make Zenzai (Oshiruko) much faster. I have an Instant Pot, so here I share how to make the delicious red bean soup using uncooked azuki beans in exactly one hour!
I love my Instant Pots (I have two models this and this) and make this recipe all year round using them. Compared to the stovetop method, pressure cooking really cuts down my time in the kitchen and it’s been a lifesaver! I can do other chores while preparing my favorite, delicious red bean soup!
Method 2: Cook in a Pot over Stovetop
You don’t have a pressure cooker? No worries, I’ll show you how to make it in a traditional method!
Method 3: Use Red Bean Paste
If you want to make Zenzai as quickly as possible, there is even a faster way. Use store-bought red bean paste. You just need to remember they tend to be a bit sweeter than your homemade version, so you might need to adjust the sweetness.
Or if you end up making a big batch of homemade red bean paste (Anko), you can enjoy Zenzai any time! I keep mine frozen all the time and make various Japanese sweets such as Dorayaki, Daifuku, or Dango.
A Great Use of Mochi from 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 and eat it for good health and fortune for the New Year. You can read more about this cultural ceremony and tradition in my other post.
There is one thing you have to remember for the Kagami Biraki ceremony: never “cut” the mochi when you break it into pieces. The action reminds the Japanese people of Seppuku (切腹), ritual disembowelment during the old times, and they believed it as a sign of bad luck. Therefore, the common way is to break the mochi with a wooden hammer or do it with your hands.
After mochi is broken into pieces, we toast them until nicely brown and put them in Zenzai to enjoy!
Other Delicious Sweets on Just One Cookbook:
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Zenzai (Oshiruko) – Red Bean Soup with Mochi
Ingredients
Using Dried Azuki Beans (makes 4–6 bowls)
- 1 cup azuki beans (7 oz)
- 4 cups water
- 1 pinch Diamond Crystal kosher salt
- ¾–1 cup sugar
Using Store-bought or Homemade Red Bean Paste (Anko) (makes 1 bowl)
- ½ cup sweet red bean paste (anko) (3.5 oz; you can make homemade Anko or Pressure Cooker Anko)
- ½ cup water (add more if you desire)
- 1 pinch Diamond Crystal kosher salt (to taste)
To Serve
- 4 pieces Japanese rice cake (mochi) (you can buy kirimochi or make my recipe for homemade mochi or shiratama dango)
Instructions
To Make the Zenzai with Dried Azuki Beans (4–6 bowls)
- Gather all the ingredients.
Option 1: Pressure Cooker Method
- Rinse 1 cup azuki beans carefully until the water is clear. Discard any damaged beans that are floating. Drain the water and transfer the beans to the pressure cooker (I use an Instant Pot).
- Add 4 cups water. Cover and lock the lid of your pressure cooker. Make sure the steam release handle points at Sealing and not Venting.
- Turn on your pressure cooker and select High pressure for 15 minutes (or 10 minutes for slightly firmer beans). For an Instant Pot, select Manual or Pressure Cooker mode, select High pressure, and adjust the cooking time.
- If you are using a stovetop pressure cooker, cook on high heat until High pressure is reached. 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. Let the pressure release naturally for 30 minutes. Before you open the lid, turn the steam release handle to Venting and release any leftover pressure. For a stovetop pressure cooker, remove the pot from the heat and let the pressure release naturally.
- Add 1 pinch Diamond Crystal kosher salt (to taste) and ¾–1 cup sugar into the pot.
- Press the Sauté button and select Low heat. Stir occasionally for about 5 minutes until the sugar dissolves completely.
- After cooking for 5 minutes, the soup will be a bit darker in color, too. Keep it warm while you prepare the mochi (please scroll down).
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) over the azuki beans. Turn down the heat to medium low and keep it simmering for the next 1 to 1½ hours. Tip: The otoshibuta will prevent the beans from dancing around too much. You can make your own with aluminum foil.
- Some water will evaporate, so add more water as needed to keep the beans submerged. After 1 hour, pick up one bean and mash it with your fingers. If it mashes easily, it‘s done. Otherwise, cook for another 15 minutes and check. 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 (please scroll down).
To Make the Zenzai with Red Bean Paste (1 bowl)
- In a small saucepan, combine store-bought ½ cup sweet red bean paste (anko) or homemade red bean paste and 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
- Cut 4 pieces Japanese rice cake (mochi) into halves or quarters. Place them in the toaster oven (or the oven). If you‘re using fresh homemade mochi, add it to the soup to warm it up. If it‘s frozen, then boil it in a pot until soft.
- Toast the mochi until puffed up and nicely brown, about 10–12 minutes.
To Serve
- Serve the red bean soup and mochi in a bowl. 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 (Oshiruko).
Nutrition
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.
[…] Dango (白玉団子) is made of Shiratamako and often served with Zenzai (Oshiruko), Anmitsu, and Mitsumame. Make them at home following my […]
[…] bean pastes are used in many delicious Japanese sweets such as Anmitsu, Daifuku, Dango, Dorayaki, Oshiruko / Zenzai, Taiyaki, Manju, and […]
[…] On Sunday, some of the other ALTs and I attended a Zenzai party hosted by a group of Japanese ladies in Yatsushiro who teach us Japanese every Wednesday. Zenzai or “Sweet Red Bean Soup” is made from adzuki beans, sugar and thick “mochi” or rice cakes. I didn’t snap any photos while we were eating – but this recipe gives you the idea: https://www.justonecookbook.com/zenzai-red-bean-soup/ […]
[…] Zenzai/Oshiruko (Red Bean Soup) […]
[…] You find shiratama dango in wagashi (和菓子, Japanese confectionery) such as Anmitsu or Zenzai (Oshiruko). […]
Aaah finally I found this recipe! First time I try this was when I hiked Mount Tsukuba last year, and now I’ve been craving it again because of the sweetness from anko and chewiness from the mochi, love it! Thank you for sharing it Nami-san!:)
Hi Fisti! I’m excited that you can re-create this recipe at home! Hope you enjoy! I LOOOOOOOVE zenzai. It’s my favorite sweet treat all year around. 🙂
Can I make this recipe with koshian?
Hi Haru! Yes, you can make it with Koshian. 🙂
Sweet!
Thank you. I’m gonna try and make this on the weekend. Looks good.
Hi Nami,
My family loves your red bean soup so I make it on a weekly basis. Just wondering if you have a recipe for sweet black sesame soup. Thanks.
Hi Darlene! I’m so happy to hear that. I haven’t had it for a while and I definitely want it with mochi!
I had never heard of the sweet black sesame soup, so I googled. I learned that it’s a Chinese dessert. I haven’t tasted this before. I have to give it a try when I see it.
My blogger friend has the recipe: http://www.chinasichuanfood.com/black-sesame-pastesoup/
Hope that helps!
When you bake the dumpling are they already boiled or is it the raw dough? And do you have suggestions for the baking temperature and time?
Hi Graig! I updated the recipe with step-by-step picture from another post. You would toast in a toaster oven or oven (or even frying pan).
I have a video of toasting mochi in the toaster oven here (@0:50).
https://www.justonecookbook.com/how-to-enjoy-japanese-mochi/
Hope this helps!
Just want to tell u that ur photographs keeps getting better n better. Love that touch of mini getta next to the zenzai
Hi Susan! Aww you’re so kind. Thank you very much! I’m glad you noticed the geta. I used to put more small props in the picture… 😀
Can you show us how tomake mochi from scratch?not the trational one though,i hear its labor intensive. But i heard that there are other ways to make it…i miight not find mochi rice though…some sort of flour? The stovetop version please,im uncomfortable using the microwave…
Hi Mikah! Yeah the traditional mochi is a bit labor intensive. You can make shiratama dango which takes about half hour or less to make.
I have one tutorial here that requires cooking over stove.
https://www.justonecookbook.com/recipes/mitarashi-dango/
You can use mochiko (some people think it’s easier to find this one), but you need to adjust the amount of water (use less water).
Hope this helps, and enjoy! 🙂
Hi Nami,
I tried making your zenzai soup ytd, overall it was quite good, and I already want to try the recipe a second time. Just a quick question, I used anko that I had chilled in the freezer and boiled it with water, however the two don’t seem to be able to blend? The red beans and water remained separate even after I had boiled them together, is it supposed to be like that?
I toasted the mochi in my oven and they turned out perfect! helped myself to two big chucks!
Hi Marilyn! It depends on how you cooked anko (if homemade). If you can still see the bean, then the outcome of zenzai is liquid + beans. Only if you use “koshi an” (paste texture of red bean), the liquid will be thicker and blend in. If you feel it’s watery, cook a little longer to reduce a bit. If you prefer the liquid to be thicker, then you may want to use koshi an (I don’t have a recipe yet, but Japanese grocery store sells koshi an (you wont’ see any bean shape). Hope this helps…. 🙂
Thanks Nami!
I’m using canned sweetened red bean paste.
I’ll try to reduce it more next time.
お返事ありがとうございます!
どういたしまして!:)
I love zenyai, thank you for this recipe and for your wonderful site!
I have already made your mochi, and it was perfect.
Domo!
Hi Tanya! So happy to know you like zenzai too! This is a wonderful snack in winter months. I enjoy eating mochi too, so I always look forward to zenzai with mochi on cold days. 🙂 Glad to hear you enjoy my mochi (strawberry mochi?) recipe. Arigato!
Nami, the recipe for Red Bean Soup looks like something I would want to try. I would also like to know where you purchased your “props” the tiny getta sandals? My daughter would love to have those on her table the next time she prepares a Children’s Day feast.
Thank you,
Sharon
Hi Sharon! I hope you enjoy this recipe! I think I got this geta from Daiso (Japanese $1 store). They have small (and cheap) Japanese decorations stuff there. They have online store, but they only sell selected things… Sorry I cannot help much. 🙁
Here’s the link for Daiso: http://www.daisojapan.com/
Tried this tonight with Shirakiku brand koshi an–now in a easy to squeeze out package– and homemade mochi. My family enjoyed the quick treat on a rainy night in Honolulu. I look forward to trying your other recipes!
Lori Bruner Okamura
Hi Lori! I have been thinking about making this for several days now. I’m a huge anko fan and I can eat it everyday… 🙂 So happy you enjoyed this. Thank you for letting me know!