📝 About This Recipe
Katsuobushi is the backbone of Japanese cuisine, a masterfully preserved skipjack tuna that transforms from a fresh fillet into the 'world’s hardest food.' This traditional process involves simmering, multiple stages of smoking, and a unique fermentation that concentrates the deep, smoky, and savory flavors. The resulting blocks are shaved into delicate flakes that provide the essential umami punch for dashi and garnishes.
🥗 Ingredients
The Fish
- 2 whole fish Fresh Skipjack Tuna (Katsuo) (approx. 3-4 kg each, extremely fresh)
- 1/2 cup Coarse Sea Salt (for cleaning and surface preparation)
The Simmering Liquid
- 10-15 liters Filtered Water (enough to fully submerge the fillets)
Smoking & Curing Materials
- 10 lbs Oak Wood Logs (for primary smoking)
- 5 lbs Cherry Wood Chips (for aromatic depth during later smoking stages)
- 5 lbs Pasania (Castanopsis) Wood (traditional wood for Japanese smoking)
Fermentation Stage
- 1 packet Aspergillus glaucus culture (Koji-mold starter specific for Katsuobushi)
- 2 pieces Cedarwood Boxes (for the fermentation/molding process)
👨🍳 Instructions
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1
Begin with 'Namagiri' (cleaning). Fillet the skipjack tuna into four longitudinal sections (two back fillets and two belly fillets). Remove the head, internal organs, and the fatty 'chiai' (dark meat) along the spine to prevent rancidity.
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2
Arrange the fillets carefully in a 'Kagidate' (metal basket). Submerge them in a large pot of water heated to exactly 90°C (194°F). This 'Shajuku' process should last 60 to 90 minutes depending on the size of the fillets; do not let the water boil as it will damage the protein structure.
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3
Once simmered, perform 'Hone-nuki' (de-boning). While the fish is still warm, use tweezers to meticulously remove every small bone from the flesh. Use a small knife to scrape away any remaining skin and scales.
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4
Start the 'Baikan' (smoking) process. Place the fillets in a smoker using oak and cherry wood. The first smoke, known as 'Kyuba,' should last for several hours at a temperature of 80°C. This sets the surface and begins the dehydration.
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5
Allow the fish to rest for 24 hours. This allows moisture from the center of the fillet to migrate to the surface. Repeat the smoking process 10 to 15 times over the next few weeks, gradually decreasing the temperature.
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6
After the final smoke, the fish is now 'Arabushi.' Scrape the surface of the blackened Arabushi with a knife to remove tar and fats. The fish should now feel like a hard piece of wood.
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7
Begin the 'Kabitsuke' (molding) stage. Place the cleaned fillets into cedar boxes and inoculate them with Aspergillus glaucus culture. Store in a room with 85% humidity and a temperature of 25°C for about 2 weeks until a layer of blue-green mold appears.
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8
Move the molded fish outside for 'Hinashi' (sun-drying). Lay them on mats in direct sunlight for 2-3 days. The UV rays and heat work with the mold to break down fats and concentrate the amino acids.
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9
Brush off the old mold and return the fish to the cedar boxes for another round of molding. Repeat the molding and sun-drying cycle 3 to 4 more times. This can take 3 to 5 months.
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10
The process is complete when the mold no longer grows and the block sounds like metal when tapped together. This is now 'Hongarebushi.' Store in a cool, dry place indefinitely.
💡 Chef's Tips
Always use the freshest skipjack tuna available; any oxidation in the raw fish will result in a fishy, bitter Katsuobushi. Temperature control during the simmering phase is critical; if the water boils, the fillets will break apart and lose their shape. When smoking, ensure the wood is seasoned and not resinous (avoid pine), as this will impart a chemical taste to the fish. During the molding phase, if black or red mold appears instead of the desired blue-green/grey mold, discard the batch as these are toxic contaminants. To use the finished product, you must use a 'Katsuobushi kezuriki' (a traditional wooden shaver box) to produce the thinnest possible flakes.
🍽️ Serving Suggestions
Use the freshly shaved flakes to make 'Ichiban Dashi' by steeping them with Kombu in hot water for a clear, elegant soup base. Sprinkle generously over Okonomiyaki or Takoyaki to watch the flakes 'dance' from the rising steam. Mix finely shaved flakes with a dash of soy sauce and use as a savory filling for Onigiri (rice balls). Serve atop chilled silken tofu (Hiyayakko) with grated ginger and green onions for a refreshing appetizer. Fold into warm steamed rice with a little butter and soy sauce for a classic 'Neko Manma' (cat rice) comfort meal.