Ingredients

   
120g soy sauce
120g citrus juice (lemon + orange, or yuzu)
  Zest from 1 lemon
30g mirin
10g katsuobushi (dried bonito flakes), packed
6g kombu (dried kelp)

Steps

  1. Combine all ingredients in a sterilized mason jar. Mix well.

  2. Steep in the refrigerator overnight (minimum). For best flavor, steep several days to a week.

  3. Strain through a fine-mesh sieve. Transfer to a clean jar.

Notes

  • Equal parts soy sauce and citrus juice is the core ratio. Mirin adds sweetness, kombu and katsuobushi add umami depth.
  • Use a mix of citrus — lemon + orange is a good default. Yuzu is traditional if you can get it.
  • The longer it steeps, the deeper the flavor. Some restaurants steep for a month.
  • Keeps refrigerated up to a month (with mirin). If substituting sugar + water for mirin, use within a week.
  • Use for: shabu shabu dipping sauce, tataki, grilled oysters, salad dressings, cold tofu, spring rolls.
  • Save the spent kombu and katsuobushi for furikake.
  • For vegetarian: omit katsuobushi or substitute 1–2 dried shiitake mushrooms.