📝 About This Recipe
Widely regarded as the world's hardest food, Katsuobushi is the soul of Japanese cuisine, providing the deep umami foundation for authentic dashi. This traditional 'Hon-Karebushi' method involves a transformative process of simmering, smoking, and noble-mold fermentation that turns fresh skipjack tuna into a crystalline, ruby-red block of pure flavor. It is a labor of love that rewards the patient cook with a depth of savory complexity that no store-bought flake can replicate.
🥗 Ingredients
The Fish
- 2 whole fish Fresh Skipjack Tuna (Bonito) (approximately 4-5kg each, extremely fresh)
Simmering Liquid
- 20 liters Filtered Water (enough to fully submerge the fillets)
Smoking Materials
- 10 kilograms Oak Wood Chips (or Quercus serrata for authentic aroma)
- 2 kilograms Cherry Wood Chips (for a subtle sweetness)
Fermentation Culture
- 1 teaspoon Eurotium herbariorum spores (Noble mold starter specifically for Katsuobushi)
👨🍳 Instructions
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1
Clean the tuna by removing the head and viscera. Carefully fillet the fish into four longitudinal sections (two back fillets and two belly fillets), removing the dark bloodline and bones.
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2
Arrange the fillets in a large simmering basket. Heat the filtered water to exactly 75-90°C (167-194°F). Do not let it boil, as this will damage the delicate proteins.
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3
Submerge the fillets in the hot water for 60 to 90 minutes. This 'Shajuku' process firms the flesh and sets the protein structure.
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4
Remove the fillets and allow them to cool slightly. While still warm, use tweezers to meticulously remove any remaining small pin bones and skin fragments.
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5
Prepare a smoking chamber using oak and cherry wood. Place the fillets on racks and smoke them for 6-8 hours at a temperature of 80°C (176°F).
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6
Rest the fish overnight to allow moisture from the center to migrate to the surface. This is called 'settling'.
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7
Repeat the smoking and resting cycle 12 to 15 times over the next 3 weeks. The fish will become dark, hard, and significantly smaller as it loses 70% of its moisture.
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8
Scrape the surface of the smoked fish (now called 'Arabushi') to remove the outer layer of tar and soot, revealing a smooth, dark surface.
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9
Place the blocks in a humidity-controlled fermentation box (Koji-muro) and inoculate with Eurotium herbariorum spores.
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10
Allow the noble mold to grow for 2 weeks in a warm, humid environment until the blocks are covered in a fine, greyish-green fuzz.
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11
Remove the blocks and sun-dry them for 2-3 days. Brush off the old mold carefully.
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12
Repeat the molding and sun-drying process 3 to 4 more times. This enzymatic action breaks down fats and creates the signature umami compounds.
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13
The process is complete when the block sounds like a piece of wood when tapped together and the interior is a translucent, ruby-red color.
💡 Chef's Tips
Always use the freshest skipjack possible; any oxidation in the fat will lead to a rancid flavor. Maintain strict temperature control during the simmering phase to prevent the fish from falling apart. Ensure the smoking wood is seasoned and bark-free to avoid bitter creosote deposits. During the molding phase, if any black or blue mold appears, discard the batch immediately as these are toxic. Invest in a high-quality 'Katsuobushi Kezuriki' (wooden plane box) for shaving the blocks into paper-thin flakes.
🍽️ Serving Suggestions
Shave into paper-thin flakes and steep in 85°C water with Kombu for the ultimate Ichiban Dashi. Sprinkle freshly shaved flakes over silken tofu (Hiyayakko) with a dash of soy sauce. Use as a savory topping for Okonomiyaki or Takoyaki to watch the flakes 'dance' from the heat. Fold into warm, high-quality Japanese rice with a little butter and soy sauce for a 'Neko-manma' (cat rice) treat. Pair with a dry, cold Junmai Ginjo Sake to complement the smoky, fermented notes.