Soy-Based Dipping Sauce for Sashimi

Plain soy sauce at sushi restaurants in Tokyo? Almost never. This warm, simmered sauce called tosa-joyu is what serious sashimi gets dipped in, and the difference is night and day.

The technique is simple but transformative. Soy sauce, sake, and katsuobushi (smoked, fermented, dried bonito tuna shavings) get brought to a quick boil. The katsuobushi steeps just long enough to release its smoky umami before being strained out. The sake cooks off, leaving behind only its delicate background sweetness.

The straining step matters. You want the deep flavor of the bonito infused into the soy sauce, but not the woody bits of katsuobushi clinging to your sashimi.

Cool the sauce completely before serving. Sashimi is a cold dish and warm dipping sauce muddles delicate fish like fluke or tuna.

Fresh wasabi mixed from powder is the proper finish. Stir it directly into your dish of sauce, or place a small dab on the fish itself for purists.

Chef Tips

• Use a fine-mesh strainer or cheesecloth to catch every flake of bonito.
• Make the sauce a day ahead. The flavor deepens overnight in the fridge.
• Mix wasabi powder with cold water just before serving for the sharpest heat. Too soon and it dulls.
• This sauce works on more than sashimi: try it as a tofu dressing, a noodle dip, or a finishing drizzle for grilled fish.

Variations

• Add a few drops of fresh lemon or yuzu juice for a citrus-bright ponzu-style variation.
• Stir in 1 teaspoon of grated daikon for a peppery, traditional accompaniment to fatty fish.
• Use tamari and gluten-free sake for a celiac-safe version with the same depth.