Japanese Kakinohazushi Persimmon Leaf Sushi Nara Heritage

Ingredients

• For the fish
• 300 g mackerel fillet, skin-on, pin-boned, sashimi-grade
• 30 g fine sea salt, 10% of fish weight, for first-stage cure
• 100 ml rice vinegar, plain, unseasoned, for second-stage marinade
• For the shari
• 300 g Japanese short-grain rice, rinsed until water runs clear
• 330 ml water
• 40 ml rice vinegar, slightly less than standard nigiri proportion
• 15 g caster sugar
• 6 g fine sea salt
• Assembly
• 12 fresh persimmon leaves, mid-to-late summer, full-sized, undamaged, at room temperature
• 1 tsp freshly grated wasabi, a thin smear per piece between fish and rice

Method

1. 1
   Lay the mackerel fillet skin-side down on a tray. Scatter the 30 g of fine sea salt evenly over the flesh. Leave uncovered at cool room temperature for 30 minutes. Rinse thoroughly under cold running water, then pat completely dry with kitchen paper. The flesh will have firmed visibly and lost its raw sheen.
2. 2
   Place the rinsed mackerel in a shallow dish and cover with the 100 ml of rice vinegar. Leave for 15 minutes, then lift the fillet free, shaking off excess vinegar. Do not rinse. The surface will be opaque and lightly tightened. Slice the fillet on the bias into pieces approximately 5 cm long and 3–4 mm thick. Set aside.
3. 3
   Cook the rinsed rice with the 330 ml of water. While hot, dissolve the sugar and salt into the 40 ml of rice vinegar. Turn the cooked rice out into a wide, flat non-reactive vessel. Pour the seasoned vinegar over the rice in a thin stream while folding with a flat paddle, never stirring. Fan the rice as you fold until it is glossy, just below body temperature, and no longer steaming. The grains must remain whole and distinct.
4. 4
   Lay a persimmon leaf flat on the work surface, underside facing up. This is where the dish lives or dies: the leaf must be fresh, undamaged, and at room temperature — cold or dried leaves will not release their volatile aromatic compounds during pressing and the defining character of the preparation will be absent. Place a slice of mackerel centrally on the leaf. Apply a thin smear of freshly grated wasabi directly onto the fish surface. Shape a portion of shari (approximately 25 g) into a compact oblong in your palm and set it firmly on top of the wasabi, pressing once with your fingers to create a unified piece. Fold the leaf snugly around the rice and fish, enclosing all sides. Repeat for all 12 pieces.
5. 5
   Arrange the wrapped pieces in a single layer, seam-side down, in a wooden pressing box or a snug-fitting non-reactive container. Lay a flat board or second container directly over the pieces and set a light weight on top — sufficient to apply gentle, even pressure across all pieces. Do not press heavily. Leave for a minimum of 12 hours and up to 24 hours at cool room temperature or in the refrigerator. The leaf fragrance will have transferred to the rice and fish surface when the pieces carry a faint, vegetal, faintly astringent scent even through the wrapper.
6. 6
   Remove the pieces from the press. Unwrap each piece immediately before serving — the leaf is discarded; it is never eaten. The rice surface should carry the faint ghost of the leaf's tannin fragrance. Serve the pieces at cool room temperature, never refrigerator-cold.