Chilled BK Udon with Oroshi Daikon

Featured Comment

It’s really good! Simple but tasty and perfect on a warm day!
– Emily (from Pintrest)

Summer in Japan means cold noodle dishes, but what when zaru udon feels too plain, hiyashi ramen or cold tantanmen too heavy, and hiyashi chuka doesn’t hit the spot?

Meet BK udon! Cold noodles that let you pile on endless toppings for the perfect customizable bowl.

chilled udon with assorted toppings thumbnail

Oroshi BK Udon

Recipe Snapshot

What is it? The customizable summer udon noodle bowl that beats the heat.
Flavor profile: Refreshing, Savory, Balanced.
Why you’ll love this recipe: From toppings to temperature, you control every element, creating your perfect bowl without being locked into someone else’s flavor vision.
Must-haves: Dashi stock (can be instant dashi granules or dashi packet), Udon noodles, Japanese style soy sauce.
Skill Level: Easy
Suitable for Meal Prep? Partially, sauce only.

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What is BK Udon?

In Japan, this dish is traditionally called bukkake udon (ぶっかけうどん), which means “udon with sauce poured over.” However, in English-speaking countries the word can be misleading, so I’ll refer to it as BK udon (a shortened name that Marugame Udon already use) throughout this post.

BK udon is defined by its method: chewy udon noodles topped with a small pour of rich, soy sauce-based broth. This can be served cold or hot in Japan. Unlike kake udon, which sits in a full bowl of light soup, BK Udon uses just enough liquid to coat the noodles. It also differs from zaru udon, where noodles are dipped into sauce.

Common toppings include grated daikon, green onions, and crunchy tempura flakes, all mixed together before eating.

BK Udon Ingredients

Ingredients needed to make chilled udon with rich broth on a white background with labels. From top to bottom, left to right: dashi, udon noodles, tempura flakes, egg yolks, bonito flakes, mirin, soy sauce, chopped green onion, grated daikon, ginger root and sugar

Udon Noodles: You can use fresh, dried, or frozen, but frozen udon noodles are my sweet spot. They’re quick, chewy, and taste amazing. Look for them in the freezer aisle of your local Asian supermarket. If you’re up for a weekend project, try my homemade udon noodles recipe!
Grated Daikon (Daikon Oroshi): This isn’t mandatory, but adding grated daikon transforms the bowl into true Oroshi BK Udon. Its refreshing bite lightens the sauce and keeps each slurp bright and clean.
Chopped Green Onions & Tempura Flakes: For me, these are non-negotiable toppings. The green onions add a fresh, sharp contrast, while the crunchy tenkasu gives every bite a fun!

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Other Topping Ideas

This type of udon is celebrated for its simplicity, but the choice of toppings can vary from restaurant to restaurant. Here are a few suggestions to spice up your dish:

Mentaiko (spicy cod roe)
Boiled whitebait (tiny fish)
Citrus: Lemon, Lime, Sudachi, Kabosu (for a tangy kick)
Cucumber (for a refreshing crunch)
Shiso leaves (adds a unique flavor)
Okra (for texture and a slight gooeyness)
Natto (fermented soybeans)
Sesame seeds (for a nutty touch)
Katsuobushi (bonito flakes for a smoky umami flavor)
Boiled egg or Onsen tamago for those who prefer cooked eggs.

Have trouble finding Japanese ingredients? Check out my ultimate guide to Japanese ingredient substitutes!

How to Make My BK Udon

Before you start: Prepare all your toppings you’re going to use.

STEP

Boil the Sauce

Pour the dashi stock, soy sauce, mirin, and light brown sugar into a saucepan and mix. Boil for 1 minute over medium heat to burn off the alcohol in the mirin.

STEP

Cool and Dilute

If serving cold, turn off the heat and add some ice cubes to cool the sauce quickly. If you’re serving hot udon, add water and reheat right before serving.

STEP

Cook the Udon

i. Cook the udon according to the instructions on the packaging. Once cooked, pour through a colander to drain and rinse with fresh water to remove any excess starch.

boiling homemade udon noodles in a pot of water

ii. Use cold water for the cold version and chill them in the colander with a few ice cubes. If serving hot, rinse with hot water.

chilling cooked udon noodles with ice in a mesh sieve over a bowl of cold water

STEP

Assemble

i. Divide the udon into serving bowls and add the sauce.

ii. Add your choice of toppings and mix well before eating.

Chilled udon topped with egg yolk, chopped green onion, grated daikon, tempura bits and bonito flakes

iii. Mix well and enjoy!

lifting mixed udon with black chopsticks

Essential Tips & Tricks

Always boil the sauce for at least 1 minute to burn off the alcohol in mirin.
If serving cold, rinse the noodles under cold running water until they’re no longer starchy, then add ice cubes to make them extra chewy and refreshing.
Don’t skip diluting the sauce (with ice or hot water depending on the version).

With these simple tips in mind, you’re set for success every time you make BK Udon.

Storage & Meal Prep

Fridge: Store sauce in an airtight container, up to 3 days. Storing cooked udon noodles is not recommended.

Freezer: Not recommended.

Meal Prep: Make the sauce in larger batches and store in the fridge for up to 3 days. Cook noodles fresh each time.

What to Serve With This Recipe

Shizake Japanese Salted Salmon served on a pale rectangular plate with sudachi and shiso leaves closeup — Japanese grilled salted salmon

BK Udon Q&A

How is BK Udon different from other cold udon dishes?

The difference is in the balance of broth and how you eat it. BK Udon uses a concentrated broth with only a small amount poured over the noodles, then mixed. In contrast, zaru udon is dipped into sauce, kake udon uses a lighter broth with more volume, and kijoyu udon relies mainly on soy sauce instead of broth.

Can BK Udon be vegetarian or vegan-friendly?

Traditionally, the broth uses bonito flakes, but you can make it fully plant-based by using vegan dashi with kombu and dried shiitake mushroom. The toppings are flexible too so you can only focus on plant-based ones like grated daikon and green onions.

Can I make BK Udon ahead of time for meal prep?

The sauce can be made 2-3 days in advance, but the noodles are best cooked fresh for the right chewy texture. You can save time by pre-chopping toppings like green onions and storing them in the fridge.