Miso Soup Recipe

Soak kombu

Place 4 cups of cold water and the kombu in a 2- to 3-quart saucepan. Let the kombu sit in the water for 20–30 minutes (or up to 1 hour) to begin releasing umami.

Heat and remove kombu

After soaking, slowly heat the water over medium heat. Just before the water reaches a gentle simmer (small bubbles around the edge, about 175–185°F / 80–85°C), remove the kombu with tongs. Do not let the kombu boil or it can turn bitter.

Add bonito and strain

Bring the water to a gentle simmer, then add the bonito flakes. Simmer for 30 seconds to 1 minute, then remove from heat and let steep for 2–3 minutes until the flakes sink. Strain the liquid through a fine-mesh sieve or cheesecloth into a clean pot or bowl. Discard or save bonito flakes for another use (e.g., okonomiyaki). This yields about 3.5–4 cups of dashi.

Warm dashi

Return the strained dashi to low heat and keep it warm; do not allow it to boil.

Dissolve miso

Place the 3 tablespoons of white miso in a small bowl or ladle. Add about 1/4 cup of the warm dashi and whisk or stir until the miso forms a smooth slurry with no lumps. This step prevents clumps when adding miso to the pot.

Combine miso with dashi

Stir the miso slurry back into the warm dashi off the heat or with the burner at the lowest setting. Avoid boiling the soup after adding miso to preserve its probiotics and delicate flavor. If using, stir in 1 teaspoon soy sauce now for added depth.

Rehydrate wakame

Place 1 teaspoon dried wakame in a small bowl and cover with cold water for 3–5 minutes until it expands and softens. Drain and squeeze out excess water. Chop or leave in bite-size pieces.

Prepare mushrooms and tofu

While dashi is heating, thinly slice the shiitake mushrooms (about 3 oz) and cut the tofu into 1/2-inch cubes. Pat tofu gently with paper towel to remove excess moisture if desired.

Simmer add-ins briefly

With the miso already returned to the warm dashi and the pot off heat or at the lowest setting, add the sliced shiitake and tofu cubes. Heat gently just until mushrooms are tender, about 1–2 minutes. Do not boil.

Add wakame and scallions

Stir in the rehydrated wakame and about 2 tablespoons thinly sliced scallions. Taste the soup and adjust seasoning with a pinch more miso dissolved in a little dashi if needed. Serve immediately.