Great ramen is all about the broth. Tonkotsu is famously made by boiling pork bones for hours until the marrow and collagen break down, emulsifying into a creamy, opaque, and incredibly rich soup.

Ingredients You Need

• 3 lbs pork neck bones and femur bones (cut to expose marrow)
• 1 large onion, halved
• 1 head of garlic, halved crosswise
• 2 inch piece of ginger, sliced
• 1 bunch scallions

Step-by-Step Instructions

1. Blanch the pork bones in boiling water for 10 minutes to remove impurities. Drain and scrub the bones clean under cold running water.

2. Return the clean bones to a large stockpot, cover with fresh water, and bring to a rolling boil.

3. Add the onion, garlic, ginger, and scallions. Maintain a strong rolling boil (not a simmer) for at least 10 to 12 hours. This vigorous boiling is what emulsifies the fat and creates the milky texture.

4. Top up with boiling water as needed to keep the bones submerged.

5. Strain the broth through a fine-mesh sieve. Serve hot with fresh noodles, tare (seasoning), chashu, and a soft-boiled egg.

If you are having trouble getting this recipe right, ensure you are measuring ingredients accurately. Baking and cooking are sciences, and the right ratios matter. Also, check your oven temperature; many ovens run hot or cold.

Troubleshooting: Why is my Tonkotsu Broth not creamy?

If you've spent hours hovering over a hot stove only to find your Tonkotsu broth looks clear and watery rather than rich and milky, don't panic. The culprit almost always comes down to one crucial element: heat control.

Tonkotsu broth relies on a scientific process called emulsification. As the collagen and fat melt out of the pork marrow, they naturally want to separate from the water. To force the fat and water to bind together into that iconic, creamy, opaque liquid, you need violent, constant agitation. You get this agitation through a rolling boil.

Many home cooks are taught that stocks and broths must be gently simmered to stay clear. Tonkotsu is the exact opposite! If you gently simmer your pork bones, you will end up with a clear, golden pork stock. You must keep the heat cranked up so the water is aggressively bubbling and crashing the fat and gelatin together for the entire 12-hour process. Keep topping up the pot with boiling water as it evaporates, keep the lid on to trap the heat, and let the rolling boil do the hard work for you.