Hiyajiru (Cold Miso Soup)

I’ve shared many Japanese dishes from my childhood here, but none hold as many memories as Hiyajiru (冷や汁). This cold miso soup is a regional specialty from Miyazaki Prefecture on the southern island of Kyushu, where I was born. Although my mom and I moved to the U.S. when I was just a few months old, I spent many childhood summers visiting my grandparents there.

Summers in Japan can be oppressively hot and humid—the kind of weather that smacks you in the face like a lukewarm mop. That’s why we often started our days in the predawn hours. My ojiichan (grandfather) would take me fishing off a stone outcropping in the local bay, while my hi-obaachan (great-grandmother) brought me to her fields to harvest summer vegetables. As the sun climbed and the heat intensified, we’d retreat to the shade of home for breakfast.

My grandparents have all passed, and Kadogawa is no longer as rural as it once was, but this Japanese cold soup is a favorite that always brings back those magical summers. Traditionally served over hot rice, Hiyajiru (which means “chilled soup” in Japanese) is a savory blend of roasted sesame, miso, and dashi. Packed with crunchy cucumber slices, this refreshing chilled miso soup is just the thing to revive your appetite on even the most sweltering days.

Why This Recipe Works

• Salting cucumbers — This draws out excess water via osmosis, transforming their texture from crisp to crunchy, and preventing the soup from becoming watered down.
• Lots of sesame — Toasted sesame seeds not only provide a rich nutty flavor that complements the miso, but they also offer a variety of textures from poppy whole seeds to a subtle creaminess and everything in between.
• Using dashi instead of fish — Some traditional recipes call for grinding grilled salted fish with the sesame seeds, but I prefer getting the flavor from dashi stock, which keeps this soup lighter and improves the texture. You can always serve this with a side of grilled fish if you want more protein.

Ingredients for Hiyajiru

• Dashi - Dashi just means "broth" in Japanese, but when it's not proceeded by a qualifier (like chicken or vegetable), it usually refers to a traditional broth made with konbu and katsuobushi. It comes in an instant powdered variety, but I prefer making it from scratch or using dashi packs, which are like tea bags filled with ground konbu and katsuobushi. 
• Toasted Sesame Seeds - You want to use toasted unhulled sesame seeds. They'll be beige to tan in color, and unhulled sesame will be puffy and matte in appearance (hulled sesame tends to look flat and glossy).  
• Miso - I usually use tanshoku miso (淡色味噌) for this, which means "light-colored miso." It's been aged for more time than white miso, but less time than red miso. This gives it a nice earthy taste and robust umami without being overwhelmingly funky. You can read more about different types of miso in my miso soup post. 
• Sugar - There's just enough sugar in the soup to take the harsh edge off of the salty miso without making the soup taste sweet. 
• Cucumbers - If you can find them, Japanese cucumbers are best for this dish, but Persian or Lebanese cucumbers will work, and you can also use English cucumbers (a.k.a. hothouse) after splitting them in half lengthwise and removing their seeds. 
• Garnishes - Hiyajiru is most commonly garnished with green shiso, myoga, and a pinch of shichimi togarashi (Japanese 7 spice). It's also delicious with thin threads of ginger, chopped scallions, or a bit of yuzu kosho. 
• Rice - The cold miso soup can be eaten as is, but it's often poured onto a bowl of rice to eat. You can follow my instructions on how to cook Japanese short grain rice if you're not familiar with it. I like to rinse the freshly cooked rice in cool water, which removes any excess starch from the surface of the rice while cooling it down. It's important to use reheated or freshly cooked rice, as cold rice from the fridge can be hard and unappetizing. You can also serve Hiyajiru over noodles or tofu. 

How to Make Cold Miso Soup

Prepare the Cucumbers

• Slice cucumbers about 1 ⁄ 16‑inch thick and toss with salt. Rest for about 20 minutes.
• Massage slices to release liquid until translucent, then squeeze out moisture before serving.

🧪SCIENCE: Osmosis draws out water from the cucumbers imparting a more crunchy texture.

Build the Soup Base

• Grind toasted sesame seeds coarsely in a mortar or grinder.
• Add sugar and continue grinding until it reaches a damp‑sand consistency.
• Incorporate miso into the mix.
• Stir in about one‑quarter of the dashi to dissolve miso lumps; then add the rest and mix until smooth.

💡TIP: Adding dashi in stages avoids clumps.

Assemble & Serve

• Place squeezed cucumbers in bowls.
• Pour chilled soup over them. You can also add some ice cubes to make the soup even colder.
• Garnish with julienned shiso, myoga slices, or a dusting of shichimi togarashi.

How to Eat Cold Miso Soup

Hiyajiru is most commonly served along with a bowl of rice. You can eat them separately, but most people chose to spoon the soup and cucumbers over the rice. I usually like to rinse the freshly cooked rice in cold water to chill it and remove excess starch from the surface of the rice. This prevents it from getting gloppy and lukewarm when you mix it with the cold miso soup. 

If you're using day-old rice, I recommend reheating it once before washing it as older rice tends to retrograde, making it hard. By reheating it, you can rehydrate the starches before chilling (which doesn't give it enough time to retrograde). 

Another option is to serve this over chilled noodles. Cold Somen Noodles add a slurpable contrast that keeps the meal cool and refreshing. For something with more bite, my Homemade Udon Noodles offer a chewy, satisfying partner to the nutty broth.

Serve this With

Hiyajiru is satisfying on its own for a light summer meal, but you can also serve it as part of a larger Japanese meal. Hiyayakko (Cold Tofu Salad) offers a cool, creamy counterpoint while adding extra protein. For a summer vegetable side with bold umami, my Miso-Glazed Eggplant (Nasu Dengaku) turns this into a more substantial dinner. If you’d like to stick with seafood, my Japanese Breakfast Salmon adds savory depth for a heartier spread.

📖 Recipe

Hiyajiru (Cold Miso Soup)

By: Marc Matsumoto

4.34 from 3 votes

Print Pin

Prep Time 30 minutes mins

Total Time 30 minutes mins

Yield 4 servings

Equipment

Japanese mortar & pestle

1 Small Glass Bowl

1 Strainer

1 cutting board

1 mandoline

Units

Grams + US CupsUS Standard

Ingredients 

1x2x3x

• 400 grams Japanese cucumber (~3 Japanese or ~4 Persian cucumbers)
• ½ teaspoon salt
• 30 grams toasted sesame seeds (~¼ cup)
• 1 tablespoon evaporated cane sugar
• ⅓ cup miso
• 2 cups dashi stock
• 4 servings cooked short-grain rice
• 5 leaves green shiso (optional, finely julienned)
• 1 myoga (optional, sliced thinly)
• Shichimi togarashi (optional)

Instructions

Step PhotosNo Photos

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• Slice the 400 grams Japanese cucumber thinly (about 1/16-inch thick) and toss them with the ½ teaspoon salt to coat evenly. Let this rest for at least 20 minutes while you prepare the soup.
  
• Add the 30 grams toasted sesame seeds to a mortar and use a pestle to coarsely grind them.
  
• Add the 1 tablespoon evaporated cane sugar and grind it in with the sesame until the mixture looks like damp sand.
  
• Add the ⅓ cup miso and grind this into a paste with the other ingredients.
  
• Add about ¼ of the 2 cups dashi stock and combine with the mixture until it's smooth.
  
• Add the remaining dashi and mix together.
  
• You can also do this in a blender or food processor by pulsing the toasted sesame seeds and sugar together before adding the miso and all of the dashi and pulsing until it's free of lumps.
• To serve the Hiyajiru, massage the salted cucumbers until they release a lot of liquid and turn translucent.
• Use your hands to squeeze out as much water from them as you can and transfer them to a serving bowl.
  
• Top with the soup, add a few ice cubes and garnish with the 5 leaves green shiso and thin slices of 1 myoga. Serve with Shichimi togarashi for sprinkling to taste.
  
• For the 4 servings cooked short-grain rice, rinse the freshly cooked (or reheated) rice in cold water to chill and remove any excess starch. Then, drain it and serve in rice bowls.
  

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Nutrition Facts

Calories • 138kcalCarbohydrates • 16gProtein • 7gFat • 6gSaturated Fat • 1gPolyunsaturated Fat • 3gMonounsaturated Fat • 2gSodium • 1536mgPotassium • 336mgFiber • 3gSugar • 6gVitamin A • 130IUVitamin C • 3mgCalcium • 139mgIron • 2mg

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