Cool Off in Summer with Japanese Somen Noodles; Recipe Uses Homemade Mentsuyu Dipping Sauce

By Tomoyo Yamada / Yomiuri Shimbun Staff Writer

11:30 JST, August 3, 2025

Cooking expert Ryuta Kijima introduces somen noodles with homemade mentsuyu dipping sauce, a classic dish perfect for hot weather. When served with mentsuyu made from carefully extracted dashi broth, it becomes a small feast.

Somen was a staple summer lunch for Kijima as a child. His late grandmother, Akiko Murakami, who was also a culinary specialist, was frequently busy with photo shoots of her cooking at home. Somen was often served to her large staff. Kijima even recalls being asked to pick myoga ginger buds from the garden.

Kijima’s grandmother and mother typically prepared the mentsuyu, though he occasionally made it himself. When he was an elementary school student, he learned a simple homemade recipe using dashi stock, soy sauce and mirin in a 4:1:1 ratio.

“My grandmother preferred a saltier mentsuyu without sugar. However, adding sugar to make it sweeter might better suit today’s tastes,” he said.

To make mentsuyu, it is crucial to prepare the dashi carefully. Dried shiitake mushrooms and kombu should ideally be soaked in water from the night before.

A slow rehydration of dried shiitake at a low temperature, in particular, draws out more flavor. “If you prepare it the day before, you can cook it immediately the next day,” Kijima said.

The rehydrated shiitake mushrooms are repurposed into a sweet, simmered shiitake. Although fresh shiitake mushrooms can be used, the concentrated flavor of the dried mushrooms is unique.

To improve the texture of the noodles, rinse the slipperiness off the surface thoroughly before chilling. To drain excess water, make them easy to pick up and improve presentation, arrange the noodles into ring shapes by wrapping a suitable amount around your fingers to make bite-sized portions.

The smooth noodles, paired with a perfectly balanced mentsuyu, ensure you will never tire of the taste. The refreshing aroma of condiments like myoga ginger buds and aojiso green perilla stimulate the appetite.

“You can eat as much as you want,” Kijima said. Since the mentsuyu will keep for about five days in the refrigerator, you can also enjoy it as a dipping sauce for soba or udon.

Somen with homemade mentsuyu

[Mentsuyu]

Ingredients:

• 5 dried shiitake mushrooms
• 2 pieces kombu kelp (15-centimeter square each)
• 20 grams katsuobushi dried bonito flakes
• 100 milliliters soy sauce
• 100 milliliters mirin
• 1-2 tsp of sugar (optional)



Directions:



1. Place 1.2 liters of water in a bowl or similar container. Add lightly washed dried shiitake mushrooms and gently wiped kombu. Soak overnight in the refrigerator.

2. Pour the contents of the bowl, including the liquid, into a pot and heat. Just before boiling, remove the kombu. Simmer on low heat for 5 minutes.

3. Add the katsuobushi dried bonito flakes to the pot and simmer on very low heat for about 5 minutes, then turn off the heat. Once the flakes sink, strain the liquid through a thick paper towel to collect the dashi stock. Set the mushrooms aside.

4. In a small pot, heat the mirin until the alcohol evaporates. Add 400 milliliters of the prepared dashi stock, soy sauce and optional sugar. Bring to a boil, then turn off the heat and let cool. Divide into serving containers.

***

[Stewed shiitake]

Directions:



1. After making the dashi, remove the stems from the rehydrated shiitake mushrooms. Thinly slice the mushroom caps at about 5 millimeters and finely julienne the stems lengthwise.

2. In a pot, combine the sliced shiitake, 150 milliliters of the remaining dashi stock from the mentsuyu process, 1½ tablespoons each of soy sauce and mirin, and 1 tablespoon of sugar. Heat the mixture. Once boiling, reduce to medium-low and simmer for about 10 minutes. Turn off the heat and let cool to infuse the flavors. Serve in a dish.

***

[Somen]

Ingredients (serves 2):

• 200 grams somen
• Myoga ginger buds to taste
• Aojiso green perilla to taste
• Grated ginger to taste



Directions:



1. Bring a generous amount of water to a rolling boil in a pot. Cook the somen noodles according to the package directions.

2. Drain noodles in a colander and rinse thoroughly under running water to remove slipperiness.

3. Add ice to the remaining water, then submerge the noodles to chill them thoroughly. Arrange by wrapping around your fingers to create bite-sized portions, then place on a plate.

4. Halve the myoga ginger lengthwise, then slice it thinly on a diagonal. For the aojiso green perilla, halve it lengthwise before finely julienning. Quickly rinse in water and squeeze out any excess moisture. Place the myoga ginger, green perilla and grated ginger into separate serving dishes. Serve along with the stewed shiitake and mentsuyu as accompaniments to the somen.