Japanese

Tonkotsu Ramen Broth

A traditional Japanese tonkotsu ramen broth made by slowly extracting flavor, collagen, and natural fats from pork trotters, neck bones, and marrow bones. An extended, vigorous boil creates the signature rich, milky-white broth, while onion, scallions, and ginger provide a subtle aromatic foundation. Made entirely from pork without added fatback, dairy, or seasonings, this broth forms the foundation for an authentic bowl of tonkotsu ramen.

Prep: 12 hr
Cook: 12 hr
Total: 1 day
Serves: 8
Makes: 3 qt
Difficulty: intermediate

Russell Toris@russelltoris

One-Pot

Ingredients

8Servings

3 lb Pig Trotters, skin on, crosscut into approximately 1–2-inch pieces
2 lb Pork Bones, neck or spine bones
1 lb Pork Leg Bones, split to expose marrow
1 whole Yellow Onion, peeled and quartered
1 bunch Scallion, roots trimmed, roughly chopped
1 pc Ginger, about 3 inches, scrubbed and thickly sliced
8 qt Water, as needed, plus more for soaking

Makes 3 qt

Nutritionper serving

Calories: 320
Carbohydrates: 2 g
Protein: 18 g
Fat: 28 g
Sugar: 1 g
Sodium: 100 mg

Method

Soak the Pork Bones

Place the pork trotters, neck or spine bones, and leg bones in a large container. Cover completely with cold water and refrigerate for 8–12 hours, preferably overnight. This initial soak helps draw residual blood and impurities from the bones and marrow, contributing to a cleaner flavor and lighter finished broth. Drain the bones and discard the soaking water.

Blanch and Thoroughly Clean the Bones

Transfer the soaked bones to a large stockpot and cover with fresh cold water. Bring to a rolling boil over high heat and continue boiling for 10–15 minutes, allowing the grey foam, coagulated blood, and other impurities to rise to the surface. Drain the bones into a large colander, discarding the blanching water. Rinse each piece thoroughly under cold running water, using a chopstick or small brush to remove dark marrow, coagulated blood, and other residue from exposed bone surfaces and crevices. Scrub the stockpot clean before proceeding.

Build the Broth

Return the cleaned bones to the 16-quart stockpot. Add the quartered yellow onion, chopped scallions, and sliced ginger. Add fresh cold water until the ingredients are covered by approximately 1–2 inches, using roughly 6–8 quarts depending on how the bones settle in the pot. Bring to a vigorous rolling boil over high heat.

Begin the Long Boil

Once the broth reaches a rolling boil, adjust the heat to maintain a continuous, active boil. The surface should be visibly bubbling and churning rather than gently simmering. During the first 30–60 minutes, skim away any remaining grey foam or dark impurities that rise to the surface, taking care not to remove the rendered fat. Continue boiling with the lid partially covering the pot if necessary to control evaporation and splattering. The vigorous boiling is essential for breaking down connective tissue and helping disperse the rendered pork fat throughout the broth, gradually developing its characteristic creamy, opaque appearance.

Maintain the Broth During Extraction

Continue boiling for approximately 10–12 hours, checking the pot every 30–60 minutes. Replenish the liquid with hot water whenever necessary to keep the bones submerged, maintaining approximately the original water level during most of the cooking process. Stir occasionally with a sturdy wooden spoon, ensuring that bones and softened connective tissue do not settle and stick to the bottom of the pot. As cooking progresses, the broth should become increasingly cloudy, opaque, and rich. The aromatics will soften and gradually break down into the broth. Avoid allowing the liquid level to fall significantly during this stage. The goal is thorough extraction and emulsification rather than premature concentration.

Develop the Final Emulsion

During the final 30–60 minutes of cooking, maintain a particularly vigorous boil to encourage the remaining rendered fat to emulsify into the liquid. Stir periodically, gently breaking apart softened connective tissue with a wooden spoon to encourage further extraction. The finished broth should be opaque, creamy, and light ivory in color, with a rich body and substantial mouthfeel. It should remain pourable rather than becoming excessively thick or greasy. Do not skim away the natural pork fat, as it is an essential component of the finished broth.

Strain the Broth

Turn off the heat and carefully remove the larger bones and solids using tongs or a slotted spoon. Pass the broth through a fine-mesh strainer into a separate clean pot or heatproof container, removing any remaining bone fragments, aromatics, and solid residue. For an especially smooth broth, strain a second time through a finer mesh. Discard the spent bones and aromatics.

Reduce to the Desired Concentration

Measure the strained broth and return it to a clean stockpot. If the volume exceeds 3 quarts, bring the broth to an active boil and reduce gradually, stirring occasionally to maintain its emulsified consistency. Stop reducing once the broth reaches approximately 3 quarts, or slightly earlier if it is already sufficiently rich and concentrated. Do not intentionally reduce below 3 quarts. If the strained broth has fallen below this volume, replenish it with hot water until it reaches the desired yield. The finished broth should have a pronounced pork flavor, rich body, and creamy texture without being excessively concentrated.

Cool and Store the Broth

Transfer the finished broth into smaller heatproof containers and place them in an ice-water bath, stirring occasionally to rapidly lower the temperature. Once sufficiently cooled, cover and refrigerate or freeze. During refrigeration, the broth may develop a gelatinous consistency and a layer of solidified pork fat. This is normal and reflects the collagen and natural fat extracted during cooking. Do not discard the fat cap. When reheating the broth, bring it to a vigorous simmer or brief boil and whisk thoroughly to reincorporate the fat into the liquid. Store refrigerated for up to 3–4 days, or freeze in airtight containers for approximately 2–3 months for best quality.