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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.
How I Developed This Recipe
When crafting this recipe, my primary focus was simplicity. Zaru udon, especially in summer, should be a breeze to prepare. Noone wants to spend hours in the kitchen in summer!
Thus, I designed a dipping sauce that’s not only straightforward but can be made in just minutes. Just chill, and you’re good to go.
But simplicity doesn’t mean skimping on details. I’ve packed this post with valuable insights, including optional toppings and tempura suggestions, for those looking to elevate their zaru udon experience!
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 bags, instant dashi, 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.
Ingredients & Substitution Ideas
- Dashi stock: Your choice of dashi works, with dashi packets and instant granule variants offering convenience. For a homemade touch, explore options like my favorite dashi, simple awase dashi, or vegan dashi recipes.
- Soy sauce: Kikkoman soy sauce is a wallet-friendly and reliable choice. For an in-depth exploration into selecting the best soy sauce in Japanese cooking, consult my dedicated soy sauce guide.
- Mirin: When on the hunt for mirin, prioritize “hon mirin” (本みりん) to ensure optimal flavor. Hinode Hon Mirin stands out for its exceptional quality and affordability. My post on the 20 Most Useful Condiments and Seasonings for Japanese Cooking is a must-read for more insights.
- Sugar: Regular sugar suffices, though I’ve developed a fondness for light brown cane sugar in my recent cooking.
- Udon noodles: Depending on availability where you live, you can choose between dried, boiled, frozen, or fresh udon. I usually opt for frozen since they can be microwaved without compromising texture.
- Shredded sushi nori seaweed (kizami nori): While optional, its inclusion enhances the dish’s presentation.
- Wasabi paste: Zaru udon without wasabi feels incomplete to me, but if you’re not a fan, feel free to skip it. Whether you prefer wasabi paste or fresh wasabi is up to you.
- Grated ginger: If ginger tickles your fancy, go for it. Ginger paste offers a refreshing taste and a great option, especially if you skipped the wasabi.
- Tempura flakes (tenkasu): Add these to the mentsuyu so that they soak up all the flavor. I never eat zaru udon without tenkasu, however, omitting them is fine if they’re not to your taste.
- Finely chopped green onion: A welcome, albeit optional, garnish that adds color and freshness.
Curious about the exact brands and products that bring my recipes to life? Discover the brands and ingredients behind my recipes at the Sudachi Amazon Storefront. Explore my handpicked pantry essentials and find your next kitchen favorites!Jump to Full Recipe Measurements
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.
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 Measurements
How 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.
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 Bukkake Udon (Udon in Sauce)
Check out my Udon Recipe Roundup post for more ideas!
Zaru Udon (Cold Udon with Homemade Dipping Sauce)
- Take a small pan and add 100 ml dashi stock, 20 ml soy sauce 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.