What is Zaru Udon?
Zaru udon (ざるうどん) is a popular Japanese summer dish consisting of cold udon noodles served with a refreshing dipping sauce called “mentsuyu.”
The word “zaru (ざる)” refers to the bamboo tray they are served upon, which is not only part of the presentation but allows excess liquid (or melting ice) to drain to the plate underneath and prevents the noodles from becoming soggy. You’ll often see cold udon or soba noodles served on a “zaru” in restaurants in Japan.
Don’t worry if you do not have a zaru at home, you can makeshift your own by serving your noodles on a bamboo sushi mat placed on top of a bowl or plate to serve the same purpose.
Zaru udon can be enjoyed on its own, but it’s also commonly served with vegetable tempura such as eggplant, sweet potato, or shrimp tempura. Tempura is a light, crispy, deep-fried dish that goes perfectly with udon and soba noodles and can also be dipped in the mentsuyu sauce.
If you eat tempura and zaru udon together, it becomes “tenzaru udon (天ざるうどん).” You can check out how to make tempura in my tempura soba or authentic tempura batter recipe!
How I Developed This Recipe
When I was putting this recipe together, I wanted to keep it simple. Zaru udon should be a breeze to prepare, especially in the summer. Nobody wants to spend hours in the kitchen in the summer!
I also created a dipping sauce that’s simple to make and only takes a few minutes. Just chill, and you’re all set.
But simplicity doesn’t mean cutting corners. I’ve included lots of useful tips in this post, including ideas for toppings and tempura, for anyone looking to make their zaru udon experience even better!
What is Mentsuyu Dipping Sauce?
Zaru udon and zaru soba are served with a dipping sauce called “mentsuyu (めんつゆ).” You can easily buy a bottle of mentsuyu from Japanese supermarkets or online, but it’s also easy to make at home!
Mentsuyu is made mainly with dashi (a Japanese soup stock) and soy sauce, then sweetened with mirin and sugar. I use awase dashi which is made with kombu (dried kelp) and katsuobushi (bonito flakes). You can use dashi packets, instant dashi granules, or make it yourself with my homemade awase dashi recipe! If you don’t eat meat or fish, check out this vegan awase dashi recipe for a plant-based alternative.
Alternatively, you can check out my concentrated tsuyu sauce recipe if you want to make a big batch. In this case, you can dilute it with 1 part tsuyu, 2-3 parts water.
Visual Walkthrough & Tips
Here are my step-by-step instructions for how to make Zaru Udon at home. For ingredient quantities and simplified instructions, scroll down for the Printable Recipe Card below.
If you prefer to watch the process in action, check out my YouTube video of this recipe for a complete visual walkthrough!
Add dashi stock, soy sauce, and mirin to a small saucepan and boil for 1 minute to burn off the alcohol in the mirin. Turn off the heat and mix in the sugar until dissolved.
Transfer the mentsuyu to a heatproof jug and leave to cool. Once it’s cool to the touch, store in the fridge until it’s time to serve. Tip: Mixing will help cool it faster.
Cook your udon noodles according to the instructions on the packaging. Once cooked, pour through a sieve to drain the water and rinse with cold water. Place the sieve over a bowl and place a few ice cubes on the noodles to help chill them further.
Zaru udon is usually served with additional ingredients to allow each person to customize their sauce. Grated ginger, wasabi paste, chopped green onion, tenkasu (tempura bits) and grated daikon radish are all great options.
Transfer the udon to a zaru (or plate topped with a bamboo sushi mat) and top with kizami (shredded) nori. Serve each portion with the chilled dipping sauce and additional ingredients.
See below for how to enjoy!
Jump to Full Recipe MeasurementsHow to Eat Zaru Udon
With zaru udon, each diner receives a “zaru” tray featuring chilled udon noodles. This is accompanied by a cup of mentsuyu dipping sauce and a side plate of additional ingredients to customize and enhance the sauce’s flavor.
On the small plate, you’ll typically find wasabi, grated ginger, and spring onions. Other additions might be sesame seeds, tenkasu (tempura crumbs), grated daikon radish, or even sudachi (Japanese citrus) for a sour twist. With your personal mentsuyu dipping sauce, you control the flavor intensity!
Start by blending the extras into your sauce as desired and mixing with chopsticks. Then, dip the udon noodles briefly into the mix. Lift, savor, and relish every bite!
How to Store
Once cooked, udon noodles should be eaten as soon as possible to preserve their texture. When exposed to the air, they can dry out and become stuck together. Pouring fresh water over them can help unstick them. For best results, I recommend eating them as soon as they are cooled, but as a last resort, wrap them in plastic wrap, refrigerate, and consume within 24 hours.
If you want to take them in a lunch box, keep the noodles and mentsuyu separate, and keep them chilled with an icepack in a cooler bag. Eat up within 2 hours in summer or 4 hours in winter.
The mentsuyu sauce has a longer shelf-life and can be kept in a sterilized container in the fridge for 2 weeks, or frozen for up to one month.
Storage summary
Room temperature – 2 hours in Summer, 4 hours in Winter (with ice pack)
Refrigerated – Cooked udon (wrapped) 24 hours. Mentsuyu 2 weeks.
Frozen – 1 month.
I hope you enjoy this Zaru Udon recipe! If you try it out, I’d really appreciate it if you could spare a moment to let me know what you thought by giving a review and star rating in the comments below. It’s also helpful to share any adjustments you made to the recipe with our other readers. Thank you!
More Japanese Udon Recipes
- Chicken Yaki Udon (Udon Stir Fry)
- Kake Udon (Basic Udon Noodle Soup – hot)
- Chilled Udon with Assorted Toppings
Check out my Udon Recipe Roundup post for more ideas!
Zaru Udon (Cold Udon with Homemade Dipping Sauce)
Ingredients
- 100 ml dashi stock or make it plant-based with my shiitake and kombu dashi recipe
- 20 ml Japanese soy sauce (koikuchi shoyu)
- 20 ml mirin
- 1 tsp sugar
- 2 portions udon noodles
- kizami nori (shredded nori) optional garnish
Additions
- 1 tsp wasabi paste
- 1 tsp ginger root grated
- 2 tbsp tempura flakes (tenkasu)
- 2 tbsp finely chopped green onions
My recommended brands of ingredients and seasonings can be found in my Japanese pantry guide.
Instructions
- Take a small pan and add 100 ml dashi stock, 20 ml Japanese soy sauce (koikuchi shoyu) and 20 ml mirin. Boil for 1 minute to burn off the alcohol in the mirin and add 1 tsp sugar. Mix until the sugar has dissolved.
- Take the pan off the heat, pour the dipping sauce into a heatproof jug and leave to cool. Once cool to the touch, you can transfer it to the refrigerator. Tip: Mixing will help it cool faster.
- Cook 2 portions udon noodles according the the instructions on the packaging. Once cooked, pour the udon into a strainer to drain and rinse with cold running water. Drain once more and place the sieve over a bowl, add a few ice cubes to make the udon extra cold.
- Take two small plates and to each one, add 1/2 tsp wasabi, 1/2 tsp grated ginger, 1 tbsp tempura flakes and 1 tbsp chopped green onion (all extras are optional).
- Place each serving of udon on a "zaru" and sprinkle with kizami nori. (You can use a bamboo sushi mat on a plate if you don't have a zaru.)
- Serve each portion of udon with a cup of cold mentsuyu dipping sauce and the small plate of ingredients to flavor the sauce.
Leave a rating and a comment