Purple Vegan Udon Noodle Soup

post featured image
Bowl of Purple Udon Noodle Soup Served over a Wooden Board

I don’t know about you, but I’m always in the mood for some nourishing noodle soup. Especially a pretty purple vegan udon noodle soup full of cabbage, green onions, and a tantalizing toasted sesame flavor. Add a couple shakes of crushed red pepper and my stomach is in soup paradise!

Where can you go to get this undeniably brilliant udon brew? Why, right in your own kitchen, of course! I’ll show you how to make this one-pot, super easy, soul-warming vegetarian udon noodle soup recipe in less than thirty minutes. You’ll be enjoying many mouthwatering bowls before you can even say souper-duper.

Superstar Ingredients

We try to add as many healthy (and tasty!) ingredients that we can into our recipes to boost up your nutrient buck. These are just a few we wanted to highlight:

Purple Cabbage – This is the star of the show, because simmering purple cabbage in this soup crates a beautiful purple broth. We’re huge fans of cabbage noodle soup. Plus, cabbage is low in calories, a good source of fiber, and high in vitamins A, C, K, and B6.

Super Firm Tofu – We love tofu! It’s high in plant-based protein, healthy isoflavones, and calcium. Plus, it’s affordable, easy to find at any grocery store, and lasts a while in the fridge.

Garlic – The flavor king! Packed with vitamins B, C, manganese, selenium, and iron, garlic is always a health win. Plus, it’s incredibly good for your immune system. If you’re like us and can never add enough garlic to recipe, feel free to ramp it up in this soup!

Onions, celery, and zucchini – Bring on the veggies! These are all very low in calories, while still adding a good amount of soluble fiber, antioxidants, vitamins, and minerals. Isn’t it amazing how many benefits you can get from a single bowl of soup?

Bowl of Purple Udon Noodle Soup Served over a Wooden Board Close Up

Are Udon Noodles Vegan?

Yes, udon noodles are almost always vegan! Udon is typically made from just three main ingredients:

  • flour
  • water
  • salt

As with all things, it’s wise to check the packaging as the udon noodle ingredients may vary by brand, but when eating at restaurants or at friend’s houses, we generally assume udon noodles are vegan. You can find dozens of vegan udon recipes online, but this is one of our favorites!

Oodles of Noodles

If you’re gluten-free or maybe you just think that udon is ugly, feel free to find other neutral noodles that you do love. Here’s a quick Noodle 101:

  • Wonderful World of Wheat – Udon, soba, lo mein, egg-free wonton, ramen
  • Under the Sea-Weed – Kelp noodles
  • Rice Rice Baby – Rice vermicelli (thick or thin), chow fun
  • The Sides of Starch – Mung bean threads

With all of these vegan noodle options, you can create an entirely new style of soup by switching out the noodles, veggies, or toppings. Let your imagination run wild!

How to Serve Up This Vegan Udon

Here are a few fun ways to slightly alter this vegetable udon recipe––though, sometimes, a simple slurp right out of the bowl is best!

  • Vary Your Veggies – Swap out the purple cabbage and zucchini for sliced snow peas and carrot circles. You can choose any vegetables you like for this satisfying soup. The options are endless!
  • Pick a Different Plant Protein – If you’re not fond of tofu, substitute tender tempeh, easy edamame, or even a sprinkling of salted peanuts (or cashews).
  • Heat Up With Hot Sauce – Whether you like a little bit of spice or a whole lot of heat, consider adding a drop or two of your favorite fire in the hole. Savory Sriracha, tantalizing Tabasco, or cheeky Cholula would definitely do the trick!

Equipment You’ll Need

Purple Udon Noodle Soup

5 from 6 votes
This eye-catching spin on vegan udon noodle soup recipe has a gorgeous natural purple hue because it's loaded with purple cabbage. It's flavorful, very easy to make, and will warm you from the inside out. Magic! 
Bowl of Purple Udon Noodle Soup Served over a Wooden Board Close Up
Prep Time 15 minutes
Cook Time 15 minutes
Total Time 30 minutes
Servings 4


  • 1 tablespoon toasted sesame oil
  • 1 medium yellow onion, sliced or diced
  • 3 stalks celery, sliced into crescents
  • 3 large cloves garlic, minced
  • medium purple cabbage, roughly sliced into ribbons
  • 1 small zucchini, diced
  • 8 cups flavorful vegetable broth, or water and vegan bouillon
  • 8 ounces udon noodles, one standard package
  • ½ block super-firm tofu, cut into small cubes
  • ½ teaspoon red pepper flakes
  • 2 green onions, thinly sliced (for topping)


  • In a large pot over medium heat, add the toasted sesame oil, onion, celery, and garlic and sauté for 3-5 minutes until onion starts to become translucent. 
  • Add purple cabbage, zucchini, and vegetable broth and bring to a boil. 
  • Add udon noodles and cook according to package instructions, stirring regularly to prevent the noodles from sticking. Toss in cubed tofu. 
  • Serve topped with red pepper flakes sliced green onion. 


This vegan udon soup recipe is very versatile. Use this as a base and add in any vegetables you'd like! For a more savory tofu, feel free to bake or sauté your tofu prior to adding to the soup.


Calories: 325kcal | Carbohydrates: 56g | Protein: 14g | Fat: 6g | Saturated Fat: 1g | Polyunsaturated Fat: 2g | Monounsaturated Fat: 2g | Sodium: 2643mg | Potassium: 472mg | Fiber: 6g | Sugar: 15g | Vitamin A: 2110IU | Vitamin C: 50mg | Calcium: 79mg | Iron: 2mg
Course dinner
Cuisine Japanese
Keyword japanese vegan recipe, udon noodle soup recipe, vegan udon noodle soup

Purple Udon Noodle Soup World of Vegan-5

Storing Your Leftover Soup

Any liquid leftovers can easily be stored in a covered glass container for a few days in the fridge. To reheat, simply place in a microwave safe bowl and heat for 2 minutes or pour into a saucepan and heat over medium-high for about 5 minutes (or until desired temperature). If you wish, add extra veggies, noodles, or broth to the mixture before heating to stretch the soup farther.

You can also freeze any leftover soup for later use. Allow the liquid to cool and come to room temperature before pouring into freezer safe containers. Seal completely and then store in the freezer for up to 3 months. To defrost, take your soup out of the freezer and allow to thaw overnight in the refrigerator. Re-heat as instructed above. Your soup will still be scrumptious!

If you give this vegan udon recipe a try, we’d love to hear what you think! Leave your star rating and thoughts down below. Noodle cheers!

More Vegan Asian-Inspired Noodle Soup Recipes:

Vegan Udon Noodle Soup Recipe With Purple Cabbage And Green Onions

This Vegan Udon Noodle Soup recipe was developed by Michelle Cehn. Article written by Gina House and edited by Amanda Meth. Content copyright World of Vegan, all rights reserved. Photos by Zhoro Apostolov. This delicious cake recipe includes affiliate links when available and shopping through these links supports World of Vegan. 

newsletter offer

Get Our FREE Vegan Shopping List

Whether you love it or hate it, we all have to go grocery shopping, and it can be a little intimidating when you first start eating vegan. Our beginner-friendly shopping list includes all the grocery essentials you'll need make many satisfying vegan meals! You'll also receive a blank shopping list you can customize yourself, plus our weekly e-newsletter with delicious plant-based recipes.

Thank you for subscribing!

Leave a Comment

Your email address will not be published. Required fields are marked *

Recipe Rating

  1. 5 stars
    this noodle soup is perfect for any cold day & the thick noodles are the best.

  2. 5 stars
    It’s so fun watching the broth turn purple when you add the purple cabbage!!! And I’m all about noodle soup, especially udon. Will be making this vegan udon soup often, whenever it’s chilly outside!

  3. 5 stars
    Such a warm and nourishing soup. My hubby loves udon noodles, too. Excellent!

  4. 5 stars
    Nothing like a good soup and this one hits the spot! Yummy!

Stay Inspired!

Thank you for subscribing!