Vegan Udon Tsuyu Broth

Vegan Udon Tsuyu Broth

Last Updated on July 21, 2022


Vegan Udon Tsuyu Broth is a kombu dashi based vegan alternative to traditional udon noodle broth for making Japanese udon noodle soup. It’s 100% vegan, umami-rich kombu (kelp) dashi based, savory & light, with no high fructose corn syrup and/or any other unwanted additives. The result is a very clean and delicate vegan udon tsuyu broth that you want to make all the time. Also, it’s easy to adjust to your taste preference.

What’s Udon Tsuyu?

Udon tsuyu is a Japanese word which consists of the words “udon [うどん]” means udon noodles and “tsuyu [つゆ]” means broth (soup) or sauce.

Udon tsuyu can mean two different types:

  • Kake-tsuyu (hot broth for hot soba noodles)
  • Tsuke-tsuyu (cold dipping sauce for cold soba noodles)

This vegan udon tsuyu broth is the kake-tsuyu type which is for making hot vegan udon noodle soup!

Whether for the hot or cold udon noodles, the traditional udon tsuyu is made with bonito flakes & kombu based dashi therefore it’s not vegan. But you can make great vegan udon tsuyu at home using kombu (kelp) and a few other easy-to-find ingredients. It’s made without bonito flakes and still just as delicious as the traditional one.

You can make this vegan udon tsuyu broth using my cold brew kombu dashi or simmered kombu dashi recipe.

Udon tsuyu broth generally has a lighter color appearance in comparison to soba tsuyu broth which has a darker color. In Japan, the lighter tsuyu broth like udon tsuyu is typically referred as “kansai-style [関西風]” and the darker one like soba tsuyu is reffered as “kanto-sytle [関東風].” They both have a completely different flavor profile. Also, each broth is preferred over the other depending on the regions of the country.

Taste of Udon Tsuyu Broth

Traditional One

As mentioned, udon tsuyu (kansai-style noodle broth) is more popular in kansai region. Kansai region is located in the western part of the main island of Japan. Geographically, it includes prefectures of Osaka, Kyoto, Hyogo, Shiga, Nara and Wakayama. In the particular prefectures, Osaka and Kyoto, you can find many great udon noodle restaurants. They’re known for the light (in color) udon tsuyu broth! You may see some of them are even lighter than my broth.

Generally, udon tsuyu broth (including kansai-style udon tsuyu) is made with light soy sauce and salt. Light soy sauce gives that beautiful lighter color in the appearance than regular soy sauce. Since the use of light soy sauce is mainly for adding a touch of color, salt is also added to the broth. What the salt does is to fill in the saltiness element that the light soy sauce itself can’t cover.

Unlike the soy sauce dominant intense & sweet flavor of soba tsuyu broth, udon tusyu broth is more delicate, less soy sauce-y taste with a hint of sweetness. Overall, you can really taste the dashi (bonito + kombu for the traditional one) which is the base of any udon tsuyu broth.

Vegan Udon Tsuyu Broth

This vegan udon tsuyu broth has the same flavor profile as the traditional one but just fish-free!

  • savory and delicate (from light soy sauce)
  • slightly sweet (from mirin)
  • umami rich (from kombu)

What’s good about making this vegan udon tsuyu broth is that you can easily adjust the saltiness and/or sweetness to your taste. For example, in general I prefer less salty and less sweet while my husband likes saltier and sweeter. So, when I make this udon tsuyu broth, I use a little more salt, mirin and sugar than my personal preference to make it more enjoyable for him.

Actually, I’m originally from the kanto region. However, I grew up in the family from the kansai region. So, in my household, we’d prefer the complete opposite of the kanto-style flavor. Still to this day, I prefer lighter color udon tsuyu broth with udon noodles over soba tsuyu and soba noodle soup!

Here is an interesting part! The lighter color may appear to be also lighter in seasoning (less saltier) which is a myth. In fact, this vegan udon tsuyu is slightly saltier than soba tsuyu broth. Why? The secret is the light soy sauce!

Key Ingredient, Light Soy Sauce

Light soy sauce (usukushi shoyu [淡口醤油] in Japanese) is a type of Japanese soy sauce. It’s similar to regular soy sauce but it has a lighter color which won’t turn food dark brown. Light soy sauce is useful in dishes that you really want to highlight the natural flavor and the color of the ingredients.

In the kansai region, such as Osaka and especially Kyoto where kaiseki-ryori (a traditional/formal multi-course Japanese meal) is served, light soy sauce is commonly used as an alternative to the regular soy sauce.

Be aware that light soy sauce is a different product from “low sodium” soy sauce. The name or those two can be confusing to some people but the truth is light soy sauce just has a lighter color with more sodium content!

Also, some light soy sauce products contains high fructose corn syrup which you won’t to avoid! Read the label before you buy! For more information and which light soy sauce is good to buy, check out my Light Soy Sauce on Vegan Japanese Pantry Guide.

Why Make Your Own?

There are many reasons you want to prepare your own udon tsuyu broth.

  • It’s 100 % vegan
  • You can control the quality of ingredients
  • The recipe is authentic minus the use of bonito flakes
  • No chemicals & additives

When you see udon tsuyu base products in grocery stores, 10 out of 10, it’s not vegan. What makes it worse is the list of ingredients on those products. Often times, it contains high fructose corn syrup and other flavor additives or chemicals in it.

On the other hand, my recipe is made with real kombu (kelp) with other short list of ingredients; water, light soy sauce, mirin, sake and sea salt. You won’t believe how easy it is to make authentic udon tsuyu broth in vegan style! Unlike my vegan soba tsuyu broth, it’s sugar free!

How to Serve

Vegan udon tsuyu broth is suitable for making hot vegan udon noodle soup or somen noodles. All you have to do is to cook udon (or somen) noodles of your choice separately then pour the vegan udon tsuyu broth over the cooked noodles!

In general, udon & somen noodles taste better with light color tsuyu broth like this udon tsuyu which typically isn’t as sweet as soba tsuyu broth.


Print Recipe
5 from 32 votes

Vegan Udon Tsuyu Broth

Vegan Udon Tsuyu Broth is a kombu dashi based vegan alternative to traditional udon noodle broth for making Japanese udon noodle soup. It's 100% vegan, umami-rich kombu (kelp) dashi based, savory & light, with no high fructose corn syrup and/or any other unwanted additives.
*The default recipe yields 3 servings of broth for hot udon noodles.
**The recipe requires Kombu Dashi prepared in advance (see the link in the ingredients and/or notes.)
***The Total Time does NOT include the time to prepare kombu dashi.
Prep Time5 minutes
Cook Time15 minutes
Total Time20 minutes
Course: Broth & Stock, Main
Cuisine: Japanese
Servings: 3
Author: Plant-Based Matters



  • Place the prepared kombu dashi in a sauce pan. Cover it and cook at medium high heat until a gentle boil.
  • Once the kombu dashi is at a gentle boil, reduce the heat to medium. Add in light soy sauce, mirin, sake and salt. Continue to cook for 1-2 minutes (uncovered) until the alcohol from mirin and sake is evaporated. Adjust the heat as necessary.
  • Serve the broth over your favorite udon noodles.


Kombu Dashi

  • It’s easy to use my Cold Brew Kombu Dashi recipe as a base to make this vegan udon tsuyu broth.
  • If using my Simmered Kombu Dashi, start with 1100 ml water / 37 fl oz purified water and 11 g / 0.4 oz kombu which should make about 960-1000 ml/32-34 fl oz (4 to 4 1/4 cups) kombu dashi that you can use for this recipe.
  • The cold brew one is super easy to make but takes 8-10 hours (or overnight) soaking. On the other hand, the simmered one takes only about 1 hour (5 minutes prepping, 30 minutes soaking and 25 minutes cooking.)

Light Soy Sauce

  • Light soy sauce is a type of Japanese soy sauce that has lighter color but contains more sodium than the regular soy sauce.
  • Light soy sauce is NOT “low sodium” soy sauce.
  • I use Premium Usukuchi Soy Sauce from Umami Insider.


  • Mirin is Japanese sweet cooking rice wine which adds the natural sweetness and depth to the flavor.
  • Use high quality mirin with no high fructose corn syrup.
  • I use Organic Genuine Mirin from Gold Mine Natural Foods.


  • Sake adds a hint of sweetness and gives background flavor and the aroma.
  • The alcohol content will be cooked off.
  • Be sure to look for vegan-friendly sake. I use Organic Junmai Sake from Hakutsuru.

Sea Salt

  • I recommend using Japanese sea salt.
  • My recommendations are Uminosei Arashio, Shiomaru (blue) and Amami Coral Sea Salt from the rice factory New York.
  • Some Japanese sea salt may contain foreign sea salt but the ones I recommend is 100 % domestic Japanese sea salt.
  • 1 tsp of the Japanese sea salt I use measures about 5 g.
  • Feel free to substitute with other sea salt.

Adjusting The Flavor

  • If you don’t want to use sake, you may omit it.
  • If you want to control the saltiness, use more/less sea salt.

Serving Size

  • The default Vegan Udon Tsuyu Broth recipe yields enough for 3 servings of hot udon noodle soup (about 1000 ml.)
  • 1 serving of vegan udon tsuyu broth is about 300-330 ml/10-11 fl oz.

How to Store

  • You can store the leftover in a container with a lid and keep in the fridge for 2-3 days or in the freezer for up to 3 weeks for the best flavor.
  • Frozen vegan udon tsuyu broth can be thawed in the fridge for 36-48 hours or at a room temperature for a shorter time.
Did you make this recipe?Mention @plantbased_matters or tag #plantbased_matters!


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