Ingredients:
- 5 cups Filtered Water (1.2 Litres)
- 5 oz (15 g) Kombu (Dried Kelp, approx. 6x6 inches)
- 1 cup (25 g) Katsuobushi (Bonito Flakes, lightly packed)
Instructions:
- Wipe the Kombu: Using a damp cloth or paper towel, gently wipe the white powder (the umami compounds) off the surface of the kombu. Do not scrub or wash thoroughly.
- Steep in Cold Water: Place the kombu and the filtered water into a saucepan. Allow it to steep at room temperature for at least 30 minutes, or refrigerate for 3 hours up to overnight.
- Heat Gently: Place the saucepan over medium-low heat. Slowly bring the temperature up without stirring.
- Remove Kombu (Critical Step): As soon as small bubbles start forming on the bottom of the pan and the water reaches 185°F (85°C)—just before a rolling boil—remove the kombu sheet completely. If the kombu boils, the Dashi will become slimy and bitter. Discard the kombu.
- Achieve a Rapid Boil: Increase the heat briefly and bring the water to a full, rolling boil for a few seconds.
- Add Bonito and Rest: Turn the heat off completely. Immediately scatter the measured katsuobushi flakes across the surface of the boiling water.
- Steep: Let the flakes steep undisturbed for 1 minute (for delicate flavor) to 3 minutes (for stronger flavor). They will sink to the bottom. Do not stir or simmer the bonito flakes.
- Strain Gently: Carefully pour the entire contents through a fine-mesh sieve lined with cheesecloth (if available) into a clean container.
- Do Not Squeeze: Crucially, let gravity do the work. Do not press, squeeze, or stir the bonito flakes remaining in the sieve, as this releases astringent, bitter compounds.
- Ready to Use: The resulting Dashi should be pale gold and crystal clear. Use immediately or cool completely before storing.