Ponzu Sauce Recipe

Prepare kombu and katsuobushi infusion

Wipe the kombu with a damp cloth (do not wash under running water). Place kombu and water in a small saucepan and heat over medium until small bubbles form at the edges (do not boil). Remove from heat just before boiling, leave kombu in the water for 8 minutes to extract umami, then remove the kombu.

Add 2/3 of the katsuobushi (about 10 g) to the warm kombu liquid. Let steep for 5 minutes off the heat to infuse smoke/savoury notes, then strain through a fine-mesh sieve or a cheesecloth into a heatproof bowl, pressing lightly on the solids to extract liquid. Discard or reserve solids for other use.

Mix base ingredients

In a nonreactive bowl combine the strained kombu-katsuobushi dashi with light soy sauce, rice vinegar, mirin and water (if using to stretch the flavour). Stir to combine.

Add yuzu juice (or the lemon + lime mixture). Taste the mixture for balance of salty, sour and sweet. If you prefer a slightly sweeter ponzu, dissolve up to 1 teaspoon sugar into the warm mixture and stir until dissolved.

Add aromatics and rest

Stir in freshly grated ginger, sliced scallion and sesame oil. Cover and refrigerate for at least 2 hours (preferably 6–24 hours) to allow flavours to meld.

After resting, strain the ponzu through a fine-mesh sieve to remove ginger fibers, scallion pieces and any remaining solids. Taste and adjust: add a little more yuzu/lemon for brightness or 1/2 tsp more soy for salt if needed.

Transfer to a clean bottle or jar. Ponzu will keep refrigerated for up to 2 weeks. Shake before use; garnish with a pinch of extra bonito flakes when serving if desired.