Japan — Nagasaki, Kyushu; Chinese influence through Edo-period Nagasaki Dejima trading post; regional variations across Japan particularly in Okinawa (rafute) using awamori instead of sake
Kakuni (角煮, 'square simmered') is Japanese braised pork belly — thick blocks of skin-on pork belly simmered for 2–3 hours in a master broth of dashi, sake, mirin, soy sauce, and sugar until the fat is gelatinised, the skin is trembling and silky, and the meat is fork-tender. The name refers to the square-cut block presentation. Unlike Chinese dongpo rou (which it resembles), Japanese kakuni uses lighter seasoning, often adding kombu or dried shiitake for dashi depth, and may include a preliminary blanching in rice-washing water (kome no togi-jiru) to remove impurities. Nagasaki kakuni, particularly influenced by Chinese trading communities in Nagasaki, is considered the most refined regional variation.
Deep, sweet-savoury soy-mirin depth, trembling gelatinised fat, yielding tender meat, sticky lacquered glaze, mustard sharpness contrast
Pre-blanch pork belly in boiling water 10 minutes, drain, rinse — this removes scum and purifies the base flavour. The braising liquid should barely simmer (80–85°C) throughout — boiling produces tough, dry meat through collagen contraction. The classic simmering liquid ratio: 4 parts dashi, 1 part sake, 1 part mirin, 1 part soy sauce, sugar to taste. An otoshibuta (drop lid) ensures even distribution of liquid contact and prevents evaporation. Cook 1.5 hours, add soy and sugar in stages to prevent over-saltiness in the reduced liquid.
For a lacquered, restaurant-quality finish: reduce the braising liquid after removing the pork to a sticky glaze consistency, return the pork blocks, and baste continuously over medium heat until each block is coated in a glossy, mahogany-coloured glaze. Serve with mustard karashi and blanched negi. Overnight refrigeration allows the fat to solidify and be skimmed for a cleaner final sauce. Kakuni makes exceptional ramen topping — the braising liquid also becomes a premium seasoning tare.
Boiling rather than simmering — a vigorous boil toughens the meat before the collagen can fully convert to gelatin. Seasoning with full soy quantity from the start — it concentrates too quickly and oversalts the exterior before the interior is cooked. Not pre-blanching, which leaves gamy impurity flavours in the finished dish. Not resting the pork overnight in the braising liquid before final glazing — the flavour penetration after overnight refrigeration is dramatically better.
Tsuji, Shizuo — Japanese Cooking: A Simple Art; Nagasaki regional food documentation