You might think authentic Japanese sauces require a dozen hard-to-find ingredients or are better bought from the store. Think again!
Today, with just 4 simple ingredients and a little patience, you can brew this ultimate "Liquid Umami Gold" that will elevate your noodles, stir-fries, and marinades to restaurant quality!
5 minutes
plus additional marinating time
Ayaka
PROFILE
INGREDIENTS
When scaling the recipe, the ratios of some ingredients may require slight adjustments. Adjust as necessary and season to taste.
- 0.75cup soy sauce (200ml)
- 0.75cup mirin (200ml)
- 0.7oz kombu (20g dried kelp)
- 0.7oz katsuobushi (20g dried bonito flakes)
DIRECTIONS
Preparation
In a bowl or container, combine the soy sauce, mirin, and kombu. Let it sit overnight (or up to 1 day) to extract the rich umami.
- 1
Pour the soaked mixture (including the kombu) into a pot. Bring to a boil over medium heat, then reduce to low and simmer for exactly 2 minutes.
- 2
Add the katsuobushi (bonito flakes) and immediately turn off the heat. Let it sit for about 1 minute until the flakes sink to the bottom.
- 3
Strain the liquid through a fine-mesh sieve into a clean, glass container. Let it cool completely.
- 4
Keep it in the fridge! (Note: Since this is concentrated, dilute it with water to taste when using it as a dipping sauce or soup base for noodles!)
RecipeID
1365
Tips & Notes
- If you don't have bonito flakes, dried shiitake mushrooms work too. In that case, add them along with the rest of the ingredients in the step1.
- Keeps for about 1 month in the refrigerator.
- Small Batch Recipe: 3 tbsp. soy sauce & mirin, 1 tsp. bonito powder.
This smaller batch can be made in the microwave. Place all of the ingredients into a microwaveable bowl and microwave uncovered at 600W for 2 minutes. Alternatively, bring to a quick boil in a saucepan. Strain before using!
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Nadia Artist, Culinary Specialist, Food Coordinator & Fermented Food Expert After discovering koji seasonings, she was deeply moved by the positive physical and mental changes she experienced, inspiring her to start sharing the wonders of koji with a broader audience. Focusing primarily on social media platforms like Instagram, she shares simple, delicious, and deeply satisfying recipes combining koji with seasonal vegetables—a style that has earned her over 200,000 followers (as of August 2026). Beyond her social media presence, she works extensively on corporate recipe development, makes frequent media appearances, and writes serial columns for online magazines.