Name: How to Make Zaru Soba (Japanese Cold Buckwheat Noodles With Dipping Sauce)
Prep time: 15 min
Cook time: 10 min
Total time: 25 min
Yield: 2
Cuisine: Japanese
Ingredients: 2 bundles of soba noodles; 60ml sake (for tsuyu); 60ml mirin (for tsuyu); 100ml soy sauce (for tsuyu); 1 Tbsp sugar (for tsuyu); 1 sheet of kombu/dried kelp (for tsuyu); 1/2 handful of bonito katsuobushi flakes (for tsuyu); Shredded nori toasted seaweed (optional toppings); Wasabi (optional toppings); Thinly sliced leeks (optional toppings); Grated daikon radish (optional toppings)

How to Make Zaru Soba (Japanese Cold Buckwheat Noodles With Dipping Sauce)

SobaSummer EasyUnder 25 MinutesVegetarian Option

Zaru Soba is a simple and refreshing Japanese dish made with chilled buckwheat noodles served on a bamboo tray (zaru). You dip the noodles into a cold homemade tsuyu sauce made from soy sauce, mirin, and dashi. It’s often topped with shredded nori, wasabi, and green onions, perfect for hot summer days.

These light, nutty noodles are eaten year-round in Japan but are especially popular in summer. You can enjoy them on their own or with sides like tempura, edamame, or pickles.

Soba has been around since the Edo period and still holds deep meaning today, especially as Toshikoshi Soba, traditionally eaten on New Year’s Eve to welcome a fresh start.

Check out our ultimate guide to learn more about soba.

Here are other cold soba recipes you can try!

Zaru Soba: with dipping sauce and shredded nori
Oroshi Soba: topped with grated daikon and citrus
Soba Salad: a modern, colorful twist with fresh veggies
Mori Soba: similar to zaru, but without seaweed
Tenzaru Soba: Soba with assorted tempura

Most soba dishes are vegetarian, and with a few swaps, like using kombu dashi instead of fish-based stock, they can be made vegan. For gluten-free diets, choose buckwheat noodles, as many soba noodles also contain wheat.

To cook soba like a pro, boil the noodles in plenty of water, rinse them under cold water, and chill in an ice bath for that perfect bounce and refreshing texture. They’re best eaten fresh, but you can store leftovers in the fridge for up to 2 days.

This easy zaru soba recipe is a summer must-try! Please give it a go and enjoy a taste of Japan at home!

Instructions

1) Gather the Ingredients for Tsuyu

Prepare your ingredients for tsuyu: sake, mirin, soy sauce, sugar, kombu, and bonito flakes.

If you want a ready-made soba noodle sauce, I highly recommend this tsuyu sauce.

2) Make the Tsuyu

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Combine the sake and mirin in a small saucepan. Bring to a boil, then reduce to low heat and simmer for about 3 minutes to evaporate the alcohol. Add the soy sauce, sugar, kombu, and bonito flakes. Simmer gently over low heat for about 5 minutes.

Expert's Tip

If you're looking for authentic flavor and smooth texture, these soba noodles are an excellent choice. Made with 80% buckwheat flour from Hokkaido, they deliver the perfect bite for refreshing summer dishes like zaru soba or oroshi soba.

3) Cooling it Down

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Once cooled, strain the sauce through a fine mesh or tea strainer into a clean container.

Tip: You can reuse the leftover bonito flakes and kombu as onigiri filling or savory furikake topping. Store tsuyu in the fridge for up to one month. To serve, dilute it with cold water at a 1:4 ratio.

4) Gather the Noodles and Toppings

Prepare soba noodles, tsuyu, cold water, shredded nori, green onions, wasabi, and grated daikon.

5) Cook the Noodles

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Bring a large pot of water to a rolling boil; no salt needed. Add soba noodles and gently stir to prevent sticking. Cook for 5–7 minutes or as directed on the package.

6) Rinse the Noodles

Drain the noodles immediately. Rinse thoroughly under cold running water while gently rubbing to remove excess starch.

7) Serve & Enjoy!

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Drain the noodles well (restaurants in Japan use this udon strainer) and serve them on a chilled plate or bamboo tray (zaru). Garnish with shredded nori, green onions, or your choice of toppings.

Pour cold tsuyu into a small bowl. Dip each bite of soba noodles into the sauce and enjoy!

Ayako Kidokoro

Ayako is a recipe writer based in Frankfurt, Germany. Though she is originally from Japan, she has lived across five countries both in America and Europe. She loves writing dessert-related recipes and sharing them with Japanese Taste readers, but she also loves educating people about Japanese tradition, culture, and language. She loves exploring and making new recipes from scratch, but other than food, she also loves doing yoga to help her stay in shape and relax.

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