Chashu Pork: Marinated & Braised Pork Belly for Tonkotsu Ramen

Slow cooking yields silky, umami-rich slices that elevate every ramen bowl.

By Medha deb

Created on Sep 4, 2025

Slow cooking yields silky, umami-rich slices that elevate every ramen bowl.

Chashu pork is a classic ramen topping, prized for its rich flavor, tender texture, and delectable fattiness. Marinated and slowly braised, this pork belly preparation helps elevate any ramen bowl, especially the iconic tonkotsu ramen, into a deeply satisfying meal. In this guide, we’ll break down techniques, marinating and braising processes, key ingredients, chef’s tips for perfect slicing and reheating, and the science that makes chashu so irresistible.

Why Make Chashu at Home?

Quality Control: Choose the highest quality pork belly and fresh aromatics for cleaner, richer flavors.
Customization: Adjust salt, sweetness, and aromatics to match your palette or dietary needs.
Texture Mastery: Home techniques let you control braising time and temperature for ideal tenderness.

Restaurant-style ramen is all about powerful broths and perfect toppings, and homemade chashu lets you compete with the best ramen shops!

Understanding Chashu: Japanese-Style Braised Pork Belly

Chashu refers to pork belly that’s been rolled, tied, marinated, and slowly braised in a balanced blend of soy, sake, mirin, and aromatics. The process tenderizes the meat and infuses it with umami and sweetness. While inspired by Chinese char siu (roast pork), Japanese chashu is always braised, not roasted, and features a luscious, melt-in-the-mouth texture.

Origin: Derived from Chinese char siu, but adapted in Japan for ramen.
Cut: Pork belly is traditional, offering a balance of meat and fat.
Serving: Sliced thin after chilling, served atop steamy ramen bowls.

Essential Ingredients for Chashu Pork

Pork Belly (2lbs/900g): Choose a slab with an even mix of fat and meat. Skin-on or off as preferred.
Soy Sauce (1/2 cup): Adds depth and color.
Dark Soy Sauce (2 tbsp, optional): Brings extra savoriness and a deeper brown hue.
Sake (1/2 cup): Japanese rice wine helps tenderize the pork and adds complexity.
Mirin (1/4 cup): Sweet rice wine for subtle sweetness and glaze.
Sugar (1/3 cup): Helps balance salt and builds a glossy finish.
Rice Wine Vinegar (2 tbsp): Brightens and lifts flavors.
Ginger (1-inch piece, sliced): Adds aromatic heat.
Green Onions (whites only): Depth and sweetness.
Garlic (6 cloves, smashed): Umami and aroma.
Water (2 cups): Adjusts braising strength.

Exact ratios can be tweaked depending on pork size or personal taste.

Step-by-Step Preparation

1. Trimming and Rolling the Pork Belly

To help the chashu retain shape and ensure even cooking, the pork belly is traditionally rolled into a log and tied tightly with butcher’s twine. While optional, this step creates the signature spiral when sliced and contributes to an impressive presentation.

Trim off excess skin or bone bits if present.
From the short end, roll the belly into a tight cylinder.
Tie tightly at 1-inch intervals with butcher’s twine.
Leave at room temperature while you prepare the marinade.

2. The Balanced Chashu Marinade

The marinade mixes savory, sweet, and umami-rich elements. Traditionally, it combines:

Soy sauce
Dark soy
Sake
Mirin
Sugar
Aromatics: garlic, ginger, and scallion whites
Water to prevent oversalting

Whisk these together in a large Dutch oven or heavy-bottomed pot. Add the pork belly and ensure it’s mostly submerged in marinade, turning to coat if needed.

3. Low and Slow: The Braise

Braising (gently simmering in liquid) is key. Do not boil—a gentle simmer preserves tenderness.

Bring marinade to a gentle simmer over medium-low heat.
Cover and braise for 2 to 2.5 hours, rotating pork occasionally.
The pork is done when:
- Completely tender throughout, easily pierced with a skewer but not falling apart.
- Color is rich brown and aromatic.

Tip: If the pork is not fully covered, baste it every 20-30 minutes to ensure even flavor.

4. Chill Before Slicing

Chashu slices best when cold. Remove from braising liquid, let it cool slightly, and then refrigerate (tightly wrapped) until fully chilled—at least 4 hours, overnight preferred.

Before slicing, remove twine.
Use a sharp chef’s knife to cut thin, even slices.

5. Skim and Save the Sauce

The reserved braising liquid is a flavor-packed condiment and marinade.

Strain and skim off surface fat (save for other uses if desired).
Reduce by simmering, if you prefer a thicker glaze.
Use as a seasoning for ramen broth, to marinate eggs, or to brush on chashu slices before serving.

The Science: How Chashu Gets So Tender

Braising pork belly at a gentle simmer (about 190-200°F/88-93°C) gives time for collagen in the connective tissue to slowly convert to gelatin. This gelatin gives chashu its signature melting quality without the meat becoming dry or stringy. Rolling and tying helps the belly retain shape and distributes fat through each slice.

Long, slow heat breaks down tough fibers.
Sugars and amino acids from marinade promote a rich mahogany color (Maillard reaction).

Serving Chashu Pork

Chashu pork is usually served warm, either reheated gently in the reserved braising liquid or blowtorched briefly to caramelize the surface. Most commonly, it tops a steaming bowl of tonkotsu ramen with rich pork broth, noodles, and fixings like soft-boiled eggs, nori, and scallions.

Other Serving Ideas:

Folded in steamed buns (bao)
Layered in rice bowls (donburi)
Served with steamed greens and rice

Storing and Reheating Chashu

Refrigerate: Sliced or whole, tightly wrapped, for up to 5 days.
Freeze: For up to 2 months; thaw overnight in fridge before slicing.
Reheat: Place slices in a small pan with a splash of braising liquid, cover, and heat gently until warm.

Chef’s Tips for Perfect Chashu Every Time

Use fresh, well-marbled pork belly for best flavor and texture.
Roll and tie tightly to prevent unraveling during braising.
Don’t boil: A gentle simmer (occasional bubbles, never a hard boil) yields perfect texture.
Cool completely before slicing to keep neat, spiral rounds.
Baste occasionally if pork belly isn’t fully submerged.
Save and re-use the braising liquid—it’s flavor gold for eggs and rice!

Nutrition and Dietary Notes

High in protein and fat: Traditional chashu is rich and satisfying, best enjoyed in moderation.
Gluten-free option: Use gluten-free tamari in place of regular soy sauce if needed.
Customizable sweetness: Adjust sugar or substitute honey for natural sweetness.

Troubleshooting: Common Chashu Issues

Too Salty: Add more water to braising liquid, or brief simmer in water post-braising.
Not Tender Enough: Braise longer, as time is key to breaking down connective tissue.
Meat Falls Apart: Chashu is overcooked; next time, reduce braising time and temp.

Chashu Pork Belly: Recipe Summary (Printable Table)

Step	Description	Key Tips
Trim & Roll	Form pork belly into tight log, tie with twine	Even rolling for spiral slices
Marinate	Combine aromatics, soy, sake, mirin; add pork	Coat all sides well
Braise	Simmer gently 2-2.5h, turning occasionally	Keep heat low, avoid boiling
Chill	Refrigerate until cold before slicing	Best slices when fully chilled
Slice & Serve	Slice thin, serve in ramen or other dishes	Reheat in sauce for best flavor

Frequently Asked Questions (FAQs)

Q: Can I use other cuts of pork besides belly?

A: While pork belly is traditional for melt-in-mouth fattiness, pork shoulder works in a pinch—though it yields a leaner result and requires careful braising for tenderness.

Q: How do I keep chashu from falling apart when slicing?

A: Chill the rolled pork completely before slicing; use a very sharp knife. Wrapping tightly before chilling helps maintain its shape.

Q: Is chashu the same as Chinese char siu?

A: No—while inspired by char siu, Japanese chashu is braised rather than roasted, resulting in a softer, moister texture.

Q: Can I marinate eggs in the leftover sauce?

A: Absolutely! Chashu braising liquid is perfect for marinating soft-boiled eggs (ajitsuke tamago) for ramen.

Q: How do I reheat chashu for ramen?

A: Place sliced chashu in a pan with a spoonful of braising liquid, cover, and gently steam until hot, or torch the slices lightly for added aroma and caramelization.

Tonkotsu Ramen Broth: Pair your chashu with a rich, creamy pork bone broth for the ultimate ramen experience.
Ajitsuke Tamago: Learn how to make ramen eggs perfectly marinated in leftover chashu sauce.
Homemade Ramen Noodles: Discover techniques for chewy, springy ramen at home.

Final Tips for Ramen Perfection

Use fresh aromatics for a clean and layered flavor profile.
Don’t rush the braise: Patience yields the most tender, flavorful pork.
Experiment with sauce ratios and additional spices to make the recipe your own.

With this comprehensive guide, you have every tool needed to craft chashu pork at home—a crown jewel of authentic Japanese ramen.

References

Author

medha deb

Medha Deb is an editor with a master's degree in Applied Linguistics from the University of Hyderabad. She believes that her qualification has helped her develop a deep understanding of language and its application in various contexts.

Read full bio of medha deb