This comforting Japanese rice soup, known as zosui or osuimono, is a delightful way to enjoy a warm, nourishing meal. It's perfect for using up leftover rice and can be customized with your favorite vegetables. The combination of dashi stock, soy sauce, and mirin creates a rich, savory broth that pairs beautifully with the tender vegetables and rice.
Some ingredients in this recipe might not be commonly found in every household. Dashi stock is a Japanese soup base made from dried fish and seaweed, which can be found in the Asian section of most supermarkets or specialty stores. Mirin is a sweet rice wine used in Japanese cooking, also available in the Asian section. Make sure to check these sections when shopping for these unique ingredients.

Ingredients For Japanese Rice Soup (Zosui/Osuimono)
Cooked rice: Pre-cooked rice that serves as the base of the soup.
Dashi stock: A Japanese soup base made from dried fish and seaweed, providing a rich umami flavor.
Carrots: Adds sweetness and texture to the soup.
Mushrooms: Provides an earthy flavor and additional texture.
Spinach: Adds a touch of green and nutrients to the soup.
Soy sauce: A salty, umami-rich seasoning essential in Japanese cuisine.
Salt: Enhances the overall flavor of the soup.
Mirin: A sweet rice wine that adds depth and sweetness to the broth.
Green onions: Used as a garnish to add a fresh, sharp flavor.
Technique Tip for Making This Recipe
When preparing dashi stock, ensure it is simmered gently to extract the full umami flavor from the ingredients. Over-boiling can lead to a bitter taste. For the mixed vegetables, cut them into uniform sizes to ensure even cooking. When adding cooked rice to the soup, break up any clumps to allow it to absorb the flavors evenly. Adjust the seasoning gradually, tasting as you go, to achieve the perfect balance of soy sauce, salt, and mirin.
Suggested Side Dishes
Alternative Ingredients
cooked rice - Substitute with quinoa: Quinoa provides a similar texture and is a nutritious alternative with a higher protein content.
cooked rice - Substitute with cauliflower rice: Cauliflower rice is a low-carb option that mimics the texture of rice while adding a subtle vegetable flavor.
chicken broth - Substitute with vegetable broth: Vegetable broth is a great alternative for vegetarians and provides a similar depth of flavor.
chicken broth - Substitute with miso soup base: Miso soup base adds a rich umami flavor that complements the other ingredients well.
carrots - Substitute with sweet potatoes: Sweet potatoes offer a similar sweetness and texture, adding a unique twist to the soup.
mushrooms - Substitute with zucchini: Zucchini provides a similar texture and absorbs the flavors of the soup well.
spinach - Substitute with kale: Kale is a hearty green that holds up well in soups and provides additional nutrients.
soy sauce - Substitute with tamari: Tamari is a gluten-free alternative that offers a similar salty and umami flavor.
salt - Substitute with sea salt: Sea salt provides a cleaner, more nuanced flavor compared to regular table salt.
mirin - Substitute with rice vinegar and sugar: A mix of rice vinegar and sugar can mimic the sweet and tangy flavor of mirin.
green onions - Substitute with chives: Chives offer a similar mild onion flavor and can be used as a garnish.
Alternative Recipes Similar to This Japanese Rice Soup
How to Store or Freeze This Japanese Rice Soup
Allow the Japanese rice soup to cool to room temperature before storing. This prevents condensation from forming inside the container, which can dilute the soup and affect its flavor.
Transfer the cooled soup into airtight containers. For convenience, consider portioning the soup into individual servings. This makes it easier to reheat just the amount you need.
Label the containers with the date of preparation. This helps you keep track of how long the soup has been stored and ensures you consume it while it's still fresh.
Store the containers in the refrigerator if you plan to consume the soup within 3-4 days. The Japanese rice soup will maintain its flavor and texture during this period.
For longer storage, place the airtight containers in the freezer. The soup can be frozen for up to 2 months without significant loss of quality.
When ready to enjoy, thaw the soup in the refrigerator overnight if frozen. This gradual thawing helps preserve the texture of the rice and vegetables.
Reheat the soup gently on the stovetop over medium heat. Stir occasionally to ensure even heating and to prevent the rice from sticking to the bottom of the pot.
If the soup has thickened too much during storage, add a splash of dashi stock or chicken broth to reach the desired consistency. Adjust the seasoning with a bit more soy sauce or salt if needed.
Garnish with freshly chopped green onions just before serving to enhance the flavor and add a touch of freshness to the reheated Japanese rice soup.
How to Reheat Leftovers
Gently reheat the Japanese rice soup on the stovetop over medium heat. Stir occasionally to ensure even heating and prevent sticking. If the soup has thickened too much, add a splash of chicken broth or dashi stock to reach the desired consistency.
Use a microwave-safe bowl to reheat the Japanese rice soup in the microwave. Cover the bowl with a microwave-safe lid or plastic wrap, leaving a small vent for steam to escape. Heat on medium power in 1-minute intervals, stirring in between, until the soup is heated through.
For a quick and even reheating method, use a double boiler. Place the Japanese rice soup in the top part of the double boiler and gently heat over simmering water. Stir occasionally until the soup is warmed to your liking.
If you have a slow cooker, you can reheat the Japanese rice soup on the low setting. This method is great for maintaining the soup's texture and flavor. Stir occasionally and add a bit of dashi stock or chicken broth if needed to adjust the consistency.
For a unique twist, reheat the Japanese rice soup in a steamer. Place the soup in a heatproof bowl and set it in the steamer basket. Steam over boiling water until the soup is thoroughly heated. This method helps retain the soup's moisture and flavor.
Best Tools for Making This Recipe
Pot: Used to bring the dashi stock to a boil and cook the mixed vegetables and rice.
Ladle: Handy for stirring the soup and serving it into bowls.
Measuring cups: Essential for accurately measuring the dashi stock, soy sauce, and mirin.
Cutting board: Used to chop the green onions and any other vegetables if they are not pre-cut.
Knife: Necessary for chopping the green onions and any other vegetables.
Mixing spoon: Useful for stirring the soup to ensure all ingredients are well combined.
Serving bowls: For serving the hot soup once it's ready.
Measuring spoons: Needed to measure out the soy sauce, salt, and mirin accurately.
How to Save Time on Making This Recipe
Use pre-cooked rice: Save time by using leftover rice or microwaveable rice instead of cooking it from scratch.
Frozen vegetables: Opt for frozen mixed vegetables to cut down on prep time.
Pre-made dashi stock: Use store-bought dashi stock or chicken broth to skip the step of making it yourself.
Quick seasoning: Measure out your soy sauce, salt, and mirin in advance to streamline the cooking process.
Chopped green onions: Buy pre-chopped green onions or chop them ahead of time and store them in the fridge.

Japanese Rice Soup (Zosui/Osuimono) Recipe
Ingredients
Main Ingredients
- 4 cups Cooked rice
- 4 cups Dashi stock or chicken broth
- 1 cup Mixed vegetables carrots, mushrooms, spinach
- 2 tablespoons Soy sauce
- 1 teaspoon Salt to taste
- 2 tablespoons Mirin
- 2 tablespoons Green onions chopped
Instructions
- 1. In a pot, bring the dashi stock to a boil.
- 2. Add the mixed vegetables and cook until tender.
- 3. Stir in the cooked rice and bring back to a boil.
- 4. Add soy sauce, salt, and mirin. Adjust seasoning to taste.
- 5. Serve hot, garnished with chopped green onions.
Nutritional Value
Keywords
More Amazing Recipes to Try 🙂
- Japanese Chickpea Curry Recipe45 Minutes
- Japanese Iced Green Tea Recipe5 Minutes
- Japanese Pickled Mustard Green Recipe25 Minutes
- Japanese Fruit Jelly Recipe20 Minutes
- Japanese Braised Chicken Recipe1 Hours
- Japanese Chex Mix Recipe40 Minutes
- Japanese Dipping Sauce Recipe5 Minutes
- Japanese Sweet Egg (Tamagoyaki/Datemaki) Recipe20 Minutes
Leave a Reply