Original Tonkotsu Recipe

Blanch bones

Place pork bones and trotters in a large stockpot and cover with cold water. Bring to a vigorous boil over high heat for 10 minutes to remove blood and impurities. Skim foam regularly.

Rinse and clean

Drain bones and discard the blanching water. Rinse bones and the pot under running hot water to remove scum. Wipe out pot.

Roast aromatics

In a small skillet, heat 1 tablespoon vegetable oil over medium-high heat. Add halved onion (cut side down), smashed garlic, and smashed ginger. Brown them for 5–7 minutes until charred in spots. This deepens the broth flavor.

Simmer bones

Return cleaned bones to the large stockpot. Add roasted aromatics and tied scallions. Pour in enough fresh cold water to cover bones by about 2 inches (about 6–8 L total). Bring to a rapid boil over high heat with the lid off; once boiling, reduce heat to maintain a very vigorous rolling simmer (not a gentle simmer) — this agitation helps emulsify marrow and collagen into the broth. Simmer uncovered for 12–18 hours, occasionally skimming excess fat and foam from the surface. Add small amounts of water as necessary to keep bones submerged.

Strain and season

After the long simmer, remove bones and aromatics. Strain the broth through a fine-mesh sieve lined with cheesecloth into a clean pot. Press gently on solids to extract liquid. Skim off excess fat from the top if desired, leaving some for mouthfeel. Season with 2 teaspoons salt and adjust to taste. If broth is too thin, continue boiling uncovered to reduce and concentrate for 20–60 minutes until desired body is reached.

In a small saucepan combine dark soy, light soy, mirin, sake, and sugar. Bring just to a simmer over medium heat, stir until sugar dissolves, then remove from heat and let cool. Taste and adjust: tare should be salty and slightly sweet. Reserve at room temperature. Each bowl will get about 1–2 tablespoons.

Roll and sear (optional)

Roll the pork belly and tie with kitchen twine to maintain shape if desired. In a hot skillet, sear all sides briefly until browned for extra flavor (2–3 minutes per side).

Braise

Combine soy sauce, mirin, sake, water, sugar, smashed garlic, and sliced ginger in a pot. Add seared pork belly, bring to a simmer, then reduce heat to low and cover partially. Braise gently for 1.5–2 hours, turning occasionally, until tender. Alternatively, braise in a 300°F (150°C) oven in an oven-safe pot for 1.5–2 hours.

Cool and slice

Remove pork from braising liquid and let cool slightly. Reserve some braising liquid to brush on slices. Slice into 1/4" (6 mm) thick pieces when cool enough to handle.

Prepare eggs (if not already made)

If using ajitsuke tamago, marinate soft-boiled eggs in a mixture of 1/2 cup soy sauce, 1/2 cup water, and 2 tablespoons mirin for at least 4 hours or overnight. If already prepared, remove from marinade and slice in half lengthwise just before serving.

Cook noodles

Bring a large pot of water to a rolling boil. Cook ramen noodles according to package instructions (usually 1–3 minutes for fresh; longer for dried). Drain quickly and rinse only if required by noodle type; otherwise, transfer directly to the bowls.

Finish broth

Reheat strained tonkotsu broth to a near-boil. To each serving bowl, ladle 1–2 tablespoons of tare into the bottom. Add 500 ml (about 2 cups) hot broth per bowl (adjust to taste). Stir to combine tare with broth. Add a teaspoon of rendered pork fat and a drop of garlic oil if desired for extra richness. Taste and adjust with white pepper and a pinch of salt.

Assemble bowls

Place drained noodles into each seasoned bowl. Ladle hot tonkotsu broth over noodles. Top each bowl with 2–3 slices of chashu, half a marinated soft-boiled egg, a few pieces of menma, a sprinkle of sliced scallions (white for more bite, green for garnish), a sheet of nori, a pinch of toasted sesame seeds, and a light dusting of white pepper. Serve immediately.

If using rendered pork fat, warm it and spoon 1/2 tablespoon over each bowl for extra silkiness. For smoky garlic flavor, drizzle a small amount (1/4–1/2 tsp) of mayu (black garlic oil) over the surface just before serving.