Ingredients:

  • 4 cups (1 Litre) Filtered Cold Water
  • 1 piece (approx. 6 inches x 4 inches, 15 g) Dried Kombu (Kelp)
  • 1 cup lightly packed (20 g) Katsuobushi (Shaved Bonito Flakes)

Instructions:

  1. Prepare the Kombu: Gently wipe the kombu piece with a clean, damp cloth to remove any debris. Do not scrub off the white, powdery substance. Make two or three small slits near the center of the piece.
  2. Soak (Recommended): Place the kombu and 4 cups of cold water into a medium saucepan. Let it soak for 30 minutes at room temperature.
  3. Heat Gently: Place the saucepan over medium-low heat. Slowly bring the water temperature up. The goal is to reach a temperature just below boiling (180°F / 82°C).
  4. Remove the Kombu: Just as the water begins to produce tiny bubbles around the edges (before a proper rolling simmer), remove the kombu using tongs. Do not allow the kombu to boil, or the stock will become bitter and slimy.
  5. Bring to a Boil: Turn the heat up to medium-high and bring the remaining stock to a rolling boil quickly.
  6. Add Bonito: Turn off the heat immediately. Wait 5 seconds, then add the katsuobushi (bonito flakes) all at once.
  7. Steep Briefly: Allow the bonito flakes to steep, undisturbed, for only 30 seconds to 1 minute maximum.
  8. Strain: Gently pour the entire contents of the pot through a fine-mesh sieve (lined with muslin or cheesecloth if desired).
  9. Finish: Discard the strained bonito flakes. Do not press or squeeze the flakes, as this will release unpleasant, bitter compounds and cloud the dashi.