Ingredients:

  • 6 cups (1.5 Litres) Filtered Water, cold
  • 1 piece (15g) Dried Kombu (approx. 6 inches x 3 inches)
  • 1/2 cup (15g) Katsuobushi (Bonito Flakes), thinly shaved

Instructions:

  1. Gently Clean the Kombu: Using a damp cloth, lightly wipe any dirt or sand from the kombu. Do not rinse or scrub; the white powder (mannitol) is vital for umami.
  2. Start the Soak: Place the kombu and the cold, filtered water into a large saucepan. Let the kombu soak in the water for at least 30 minutes (or up to 3 hours) to gently awaken the flavor.
  3. Heat Slowly: Place the saucepan over medium-low heat. Heat gradually. When the water reaches 180°F (82°C) or just before it begins to boil (you will see tiny bubbles forming on the bottom), immediately remove the kombu using tongs. Do not let the kombu boil.
  4. Bring to a Boil & Add Bonito: Once the kombu is removed, increase the heat slightly and bring the remaining water to a rapid, rolling boil. Turn off the heat immediately, then toss the measured katsuobushi (bonito flakes) into the hot water.
  5. Steep (The Quick Infusion): Allow the flakes to steep, undisturbed, for only 30 to 60 seconds. Steeping for too long will result in a strong, fishy flavor.
  6. Strain and Finish: Line a fine-mesh sieve with cheesecloth (optional) and strain the entire mixture into a clean bowl or container. Crucially, do not press or squeeze the katsuobushi flakes, as this forces out bitter, cloudy sediment. The resulting dashi is ready to use immediately.