This Umami Explosion Broth is a deeply savory Nordic-inspired dashi combining kombu seaweed, smoked bonito flakes, dried shiitake mushrooms, and fermented mushroom paste. It was the base broth for the famous Tortellini in Nordic Seaweed Broth served at the Bottura × Redzepi four-hands dinner in Modena, 2019. René Redzepi contributed this broth as a Nordic reimagining of Japanese dashi, designed to complement Bottura's handmade tortellini. The result is a broth with extraordinary umami depth — clean, savory, and deeply complex.
Ingredients
Home Mode
- 15g dried kombu seaweed — about 2 large strips (available at Asian grocery stores or online)
- 20g smoked bonito flakes (katsuobushi) — about 2 loosely packed cups
- 30g dried shiitake mushrooms — about 6 medium mushrooms
- 1 tablespoon (18g) white or barley miso paste
- 1 tablespoon (15ml) soy sauce or tamari (use tamari for gluten-free)
- 1 liter cold filtered water
Chef Mode Additions
- 1 teaspoon fermented mushroom paste (or black garlic paste)
- 5g dried dulse seaweed
- 2g dried porcini powder
Instructions
Cold Soak the Kombu & Shiitake
Place kombu strips and dried shiitake in a pot with 1 liter cold filtered water. Soak at room temperature for at least 30 minutes. For maximum extraction, soak overnight in the fridge. Cold extraction draws out glutamates without bitterness — this is the foundation of your umami.
Slowly Heat the Broth
Place pot over medium-low heat. Heat slowly until small bubbles form at edges — about 60°C / 140°F. This should take 10-15 minutes. Do not boil. Boiling kombu releases bitter compounds that ruin the clean flavor profile.
Remove the Kombu
Just before the water simmers (about 70°C / 158°F), remove kombu with tongs. Leave shiitake in. The kombu has released its glutamic acid — keeping it longer adds sliminess and bitterness.
Add Bonito Flakes
Bring to a gentle simmer. Add all bonito flakes at once. Steep for exactly 3-4 minutes without stirring. The bonito adds inosinic acid, which synergizes with kombu's glutamic acid — creating umami exponentially greater than either ingredient alone.
Strain
Strain through a fine-mesh sieve lined with cheesecloth into a clean pot. Let gravity work — don't press the solids. Pressing makes it cloudy. You should have a clear, amber-gold liquid with an intensely savory aroma.
Season with Miso & Soy
Over low heat, whisk in miso paste until fully dissolved. Do not boil after adding miso — heat kills beneficial enzymes and dulls flavor. Add soy sauce. Taste: the broth should be deeply savory, slightly sweet from shiitake, with a clean oceanic finish.
Chef Mode Enhancement (Optional)
Stir in 1 tsp fermented mushroom paste or black garlic paste. Add dulse seaweed during the bonito steeping stage for a more complex marine note. Finish with a pinch of porcini powder. These additions push the umami from excellent to extraordinary.
Substitutions & Notes
| Ingredient | Substitution | Notes |
|---|---|---|
| Kombu | Dried kelp of any variety | Available in most health food stores or Asian markets |
| Bonito flakes | Additional dried shiitake + 1 tsp fish sauce | For vegetarian: use only mushrooms and add a strip of nori |
| Shiitake | Dried porcini or mixed dried mushrooms | Shiitake gives the cleanest umami; porcini adds earthiness |
| White miso | Red miso (use half the amount — it's stronger) | White miso gives sweetness; red miso gives depth |
| Fermented mushroom paste | Black garlic paste, or a pinch of MSG | These all target the same umami receptors |
Pairing Suggestions
- Serve as: Base for tortellini, ramen, or soba; sipping broth; poaching liquid for fish or vegetables
- Wine: Dry sake, unoaked Chablis, or Grüner Veltliner
- Non-alcoholic: Genmaicha tea, sparkling water with yuzu
Technique Links
- Emulsification — Used in the mantecatura of the risotto this broth often accompanies
- Fermentation — The science behind the miso and fermented mushroom paste
- Dashi Extraction — Deep dive into Japanese and Nordic broth-making