Zaru Udon Recipe

Boil water

Bring 8 cups of water to a rolling boil in a large pot. Add 1 tablespoon coarse salt to the water.

Cook udon

Add 12 oz dried udon (or fresh udon) to the boiling water. Stir gently to separate. Cook according to package instructions: about 8–10 minutes for dried thick udon or 2–3 minutes for fresh, until the noodles are tender but still slightly firm (al dente). Taste a strand to confirm texture.

Prepare ice bath

While the noodles cook, fill a large bowl with cold water and add 2 cups of ice cubes to make an ice bath.

Rinse and chill noodles

When udon are done, reserve 1/2 cup of the hot cooking water (optional — can be used to loosen sauce). Immediately drain noodles in a colander and rinse thoroughly under cold running water while gently tossing to remove surface starch and stop cooking. Transfer noodles to the ice bath for 1–2 minutes to chill completely and firm up. Drain very well before serving; shake off excess water and transfer to a serving plate or individual zaru (bamboo draining tray).

Make dashi (if using instant, skip to combine)

If using homemade dashi: combine 3 cups water with kombu and dried bonito flakes as you normally would (e.g., soak kombu then bring to near boil, remove kombu, add katsuobushi, simmer briefly, strain). If using instant dashi, dissolve the powder in 3 cups hot water according to package to yield 3 cups of dashi.

Combine sauce

In a small saucepan, combine 1 cup soy sauce, 1 cup mirin, 2 tablespoons sake (optional), 1 teaspoon sugar, and 3 cups dashi. Bring gently to a simmer over medium heat just until the mirin and sugar dissolve and the alcohol aroma softens (about 1–2 minutes). Do not boil vigorously. Remove from heat and let cool to room temperature.

Chill and adjust

Chill the mentsuyu in the refrigerator until cold. For serving, the concentrated balance here is ready to use cold as-is for dipping. If you prefer a lighter flavor, dilute 1 part mentsuyu with 1 part cold water (or use reserved noodle cooking water) in small dipping bowls to taste.

Prepare garnishes

Toast nori briefly over a low flame or in a dry pan until fragrant, then stack and slice into thin 1/8–1/4 inch julienne strips. Thinly slice scallions. If using fresh wasabi root, grate finely; if using paste, place a small amount in a ramekin for each diner.

Plate

Place chilled udon on a zaru or a shallow plate, sprinkle the cut nori on top. Pour chilled mentsuyu into individual small dipping bowls. Arrange garnishes — scallions, wasabi, bonito flakes, sesame seeds — on a small communal plate or in separate small dishes so diners can add to their dipping sauce.

Eat

Each diner takes a small portion of udon with chopsticks, dips the noodles into the mentsuyu (with or without added scallion/wasabi), and eats. If the sauce seems too strong, dilute with a little cold water or reserved noodle cooking water. Optionally, after finishing noodles, pour hot water or leftover noodle cooking water into remaining mentsuyu to make a warm, light broth to sip (sobayu style).