Ingredients:
- 4 cups (1 litre) Filtered Water
- 5 oz (15 grams) Dried Kombu (roughly 6x6 inches)
- 1 oz (30 grams) Katsuobushi (Dried Bonito Flakes)
Instructions:
- Prepare the Kombu: Gently wipe the kombu surface with a damp cloth or paper towel to remove any grit. Do not wash or scrub away the white powdery substance—this is concentrated glutamine (the umami!).
- Soak: Place the kombu piece and the 4 cups (1 L) of filtered water into a non-reactive saucepan.
- Rest: Allow the kombu to soak in the cold water for a minimum of 30 minutes, or up to 1 hour, to begin extracting its flavour gently.
- Heat Gently: Place the pot over medium-low heat. Slowly bring the water temperature up, aiming for about 180°F (82°C)—just before it begins a rolling boil.
- Watch for Bubbles: As soon as small bubbles start to form around the edge of the pot, remove the kombu immediately. If it boils, the kombu releases bitter, slimy compounds.
- Discard/Reserve Kombu: Remove the kombu piece from the water.
- Increase Heat: Bring the water back up to a fast simmer (small, rapid bubbles).
- Add Bonito: Turn the heat off completely. Add the measured katsuobushi (bonito flakes) to the hot water all at once.
- Steep: Let the katsuobushi steep undisturbed for 2–3 minutes. Do not stir or return the pot to the heat during this time.
- Strain: Carefully pour the entire contents through a fine-mesh sieve (optionally lined with cheesecloth) into a clean, heatproof bowl.
- Do Not Press: Crucially, let the stock drain completely on its own. Do not press or squeeze the bonito flakes, as this clouds the clarity and introduces bitterness.
- Cool and Store: Allow the dashi to cool quickly before using or storing. It is highly perishable and should be used within three days or frozen.