Japanese Kakuni Braised Pork Belly Nagasaki Tradition and Sauce Reduction

Ingredients

• 1 kg pork belly (buta no bara), skin-on, cut into large blocks then portioned into cubes after blanching
• 500 ml sake, divided across blanching and braising stages
• 250 ml mirin
• 150 ml soy sauce
• 40 g sugar
• 1 litre water, for preliminary blanching braise
• To serve
• 1 tsp karashi, Japanese mustard, prepared from powder
• 4 leaves leaf garnish, komatsuna or similar

Method

1. 1
   Blanch the pork belly in a large pot of cold water brought to the boil. Drain, rinse the meat and the pot thoroughly. This double-blanching step removes residual myoglobin and impurities; the water should run clear before proceeding.
2. 2
   Return the blanched pork to the clean pot with 1 litre of water and 250 ml of sake. Bring to a gentle simmer and braise, partially covered, for 1 hour. The meat should offer some resistance when pressed but show the first signs of yielding at the surface.
3. 3
   Lift the pork from the preliminary braising liquid. When cool enough to handle, cut into characteristic square blocks (kaku) of approximately 5–6 cm. The portioning now — not before — preserves the structure through the long first braise.
4. 4
   Combine the remaining 250 ml sake, mirin, soy sauce, and sugar in a heavy pot wide enough to hold the pork in a single layer. Add the pork blocks skin-side up. Place an otoshibuta (drop lid) directly on the surface of the liquid. This is where the dish lives or dies: the secondary braise in the seasoning liquor must continue at a steady, low simmer for a minimum of 2 hours — ideally 3 — until the collagen has fully converted to gelatin. The blocks should tremble at a nudge and a skewer should pass through the fat layer without resistance.
5. 5
   Remove the otoshibuta. Raise the heat to reduce the braising liquor, basting the pork continuously, until the sauce thickens to a glossy tare that coats a spoon and clings to the meat with lacquer intensity. The surface of each block should shine.
6. 6
   Remove from heat. Rest the pork submerged in the tare overnight, refrigerated. The solidified fat cap that forms on the surface should be lifted and discarded before reheating. The braising liquid will have set to a light gel; the smell on reheating should be deeply savoury and sweet-soy, with no raw alcohol note.
7. 7
   Reheat the kakuni gently in the tare until the blocks are heated through and the sauce is again glossy and fluid. Serve each portion with a small quenelle of prepared karashi and a leaf garnish alongside. The mustard should provide a sharp, bitter counterpoint when tasted against the lacquered pork.