Shiitake Dashi

Gently wipe the shiitake caps with a dry cloth to remove any dust — do not wash them, as water dilutes the surface glutamates. Place shiitake (and kombu, if using) in a glass jar or non-reactive container and cover with the cold filtered water. Seal and refrigerate for a minimum of 8 hours and up to 24. The cold extraction draws out guanylate compounds that heat would destroy, producing a cleaner, more complex umami than any quick hot-steep method.

Transfer the cold-steeped liquid to a small saucepan. Warm over low heat, watching closely. Bring to 60–70°C — just below a simmer, where wisps of steam rise and small bubbles form at the bottom of the pan, but the surface remains still. Hold at this temperature for 5 minutes. Never allow it to boil: a full boil drives off volatile aromatics, makes the dashi cloudy, and introduces a harsh, bitter note from guanylate breakdown.

Line a fine-mesh strainer with a damp muslin cloth and set it over a clean bowl. Ladle the dashi through gently — pouring from height aerates it and diminishes delicacy. Discard any sediment remaining in the muslin. Season with a pinch of salt, taste, and adjust. The dashi should taste clean, deeply savory, and slightly sweet with a long, gentle finish. Use immediately, or refrigerate for up to 4 days.