TONKOTSU: A Complete and In-depth Recipe/Walkthrough

Let me warn you that if you are looking for a quick recipe that you can “whip up in 30 minutes or less” on a Wednesday night, then this isn’t it… The first few days are mostly just prepping and marinating your toppings. Your active time spent prepping does not take as long, so it can be done before or after work. The third day is by far the busiest day. Then finally, on the fourth day, the ramen is ready to eat/serve. That said, for this recipe, I labeled each day for example as “THURSDAY”, “FRIDAY”, “SATURDAY” etc. I did this because back when I had an office job, I only had the weekends to craft ramen. So, I wrote this walkthrough based upon if you started on a Thursday, you would finish on Sunday and have enough meals for the coming week. My tonkotsu recipe yields nearly 3 liters of soup, so it should be enough for 10-12 bowls of ramen. Plus, it freezes well for up to 3 months.

If this entire walkthrough seems daunting to you, how about only making one component like the broth, ajitama or the chashu, etc until you feel comfortable undertaking the whole project? The chashu can be cut up and used for a “donburi” or rice bowl dish. Also, the ajitama make a great snack on their own!

I will be utilizing the metric system for this walkthrough. I used a ThermoPro cooking thermometer that allows you to toggle between Fahrenheit (°F) and Celsius (°C) degree readings. A digital scale should allow you to measure in grams (g) and kilograms (kg). Also, most measuring cups have millimeters (ml) and liters (L) displayed.

Equipment & Supplies needed to aid in preparation:
Measuring cup with metric display of millilitres (ml)
Fine mesh strainer
Large bowl
Food thermometer with Celsius temperature display (°C)
Digital scale with grams (g) display
Aluminum stock pot(s)
Saran wrap
Frying pan

Most of these items you will likely already have in your homes, so don’t worry!

I highly recommend using an aluminum stock pot for the soup stock versus stainless steel. Aluminum pots are less likely to scorch the cooking materials. For opaque, white tonkotsu broth, this is crucial.

Cooking twine — to wrap the pork for chashu into a log shape
A tawashi — a natural scrubbing brush to aid in cleaning the pork bones
Fishing wire — allows for a clean, slicing-in-half of the ajitama


3L of water
Pork bones (2kg –1kg of neck bones, 1kg of pig feet)
1 bulb of garlic, sliced in half

1kg Boneless pork shoulder butt/butt roast (do not use picnic shoulder)

CHASHU DRY BRINE This will be used as a pre-prep for braising
50g of brown sugar
50g of sea salt

This will be used as a pre-prep for braising
75ml of sake
350ml of water
15g of sliced ginger

CHASHU BRAISING SAUCE & AJITAMA MARINADE — After making the chashu pork, reserve 500ml of sauce to also use for marinating the ajitama.
1L of water
500ml of shoyu
50ml of mirin
50ml of sake
45g of brown sugar
10g of ginger slices
10g of garlic
1 green onion

AJITAMA BOIL: “Ajitama” are seasoned soft-boiled eggs
Up to 5 large eggs
2L of water
50ml rice vinegar (the acid helps breakdown shells to make peeling them easier)

DASHI STOCK: An “umami”-rich stock that helps to give the soup a signature Japanese taste
1L of water
15g of katsuobushi
30g of kombu
15g of gyofun (dried fish powder)
15g of niboshi, heads and guts removed
15g of shiitake mushrooms (reconstitute with water first, if dried)

SOUP TARE: “Tare”, as in a seasoning for the actual soup
30g of brown sugar
35g of sea salt
50ml of white shoyu
100ml of mirin
200ml of sake

Green onions
Karashi takana
Aromatic scallion and lard oil

Day 1: Prep work (“THURSDAY”)

Rub the pork shoulder butt (which is the meat that is going to be used for the pork chashu ramen topping), with a dry brine of 50g of sea salt & 50g of brown sugar. Place it in a baggie, letting out as much air as possible, and then store it in the refrigerator overnight to 24 hours.

In another container, for the dashi stock, combine the ingredients shown below along with the 1L of water into a container and refrigerate overnight. (If you cannot find, nor wish to use gyofun, you may omit it from the stock. Just use 30g of niboshi only instead.)

Day 2: Prep work (“FRIDAY”)

Start the soup tare by first evaporating alcohol from the sake and mirin in a saucepan. To do this, bring the temperature of the sake and mirin to 80°C.

Then add in the brown sugar, salt, white shoyu, and then the refrigerated dashi stock from the day before into the saucepan.

Heat this soup tare and dashi mixture to 60°C (this is because by adding the dashi stock from the refrigerator, it will have lowered the temperature quite a bit), then remove the kombu.

Now that the kombu has been removed, turn the heat up to 80°C , cover and let it simmer for 30 min. After 30 min, turn off the heat and strain the mixture. Once it has cooled, place the tare (which now contains dashi stock) in the refrigerator until ready to use.

Taking the baggie containing the brown sugar and salt-covered shoulder butt from the day before, add in 75ml of sake, 15g of sliced ginger and 350ml of water to the baggie. Make sure to push out as much air as possible from the baggie, then seal it closed. Again, place it in the refrigerator overnight to 24 hours. The sake and ginger will help to remove any gamey odor from the pork and the sake will also tenderize it.

Take a large container or a pot, and place all of your neck bones and pig feet into it. Fill the container to at least right above the bones. Place this container in a refrigerator overnight to draw out the blood from the bones. This will make blanching the bones easier the next day because it’s the blood in them that is the cause of the scum that floats to the top of the water. 

Day 3: Making the soup stock, chashu, and ajitama (“SATURDAY” — this will be your busiest day!)

First, start by emptying the pot with the meat and now bloody-tinted water. Be careful not to let any of the bones fall out into the sink.

Now, you will blanche the bones. Fill an aluminum pot with fresh water to right above the bones. Add in all of the neck bones and pig feet.
Bring the water to a boil, and boil for 20 minutes, uncovered, while scooping out any scum that floats to the top. To be safe, hold a piece of folded paper towel with a pair of tongs to wipe the inside of the pot at the water line. If you do not do this, the scum along the waterline is only going to cook right back into your soup stock.
I prefer to use a “tawashi”, essentially a vegetable scrubber brush, to clean my bones. After the 20 minutes of boiling, strain the pot and wash from the bones of any coagulated blood and scum with cold water and a tawashi, or scrubber brush.
*Be sure to clean the pot before returning the bones to it!* (Though this time, I just simply grabbed a new pot lol)

Now, fill the pot with 3L of water. When bringing the pot to a boil, this time, there should not be any more grayish-brown foam at the top. Raise the water to a boil, and cover the pot. Afterwards, turn the temperature down to low-medium; just enough heat to maintain the rolling boil.

Check on the stock once every 2-3 hours and to be sure that the water level is the same as with what you started. If not, add more water until you fill it to your original water level. Boil for 12-15 hours total; after about 6 hours into cooking, add in the garlic bulb. Also, pick out any marrow from the pork bones, if it is exposed. This marrow will make the broth richer with flavor.

While the tonkotsu soup stock is cooking, take the pork shoulder butt, and rinse off the brown sugar, salt, sake, ginger and water mixture. Now, arrange it into a log shape by tightly wrapping it with cooking twine, then place it in the pot with the soup stock for 2 hours. After the 2 hours, take it out and wrap it in aluminum foil to keep it from drying out, then begin making the chashu sauce.

Make the chashu sauce for the shoulder butt that you just boiled for 2 hours. Start by combining the 500ml of shoyu, 50ml of mirin, 50ml of sake, 1L of water, 45g of sugar, 10g of ginger slices, 10g of garlic and 1 green onion into a pot or saucepan. (This may sound like a lot of sauce, but it can be reused for up to 6 months if you freeze it.)
Bring the chashu sauce to 95°C in a saucepan or pot, add in the chashu pork shoulder, cover the saucepan and then allow it to simmer for 60-90 minutes.

[Once it has finished cooking, remove the chashu and reserve about 500ml of the marinade for up to 5 eggs.]
Remove the chashu from the sauce and place it onto a colander. To seal in the savory flavor and to add a nice char to the outside, heat a pan to high heat and sear all surfaces of the chashu (even the sides). No oil is needed to sear it. Once evenly seared, allow it to cool by wrapping it in aluminum foil to prevent it from drying out. After it has cooled, wrap it in saran wrap and place the chashu in the refrigerator overnight. Be sure to only slice it *after* it has cooled overnight in the refrigerator. Slicing it while hot will cause moisture loss, and make slicing more difficult. Once sliced, store the slices in the refrigerator and tightly sealed in a container until ready to eat.

For the ajitama, I prefer to make the chashu first, then use some of the leftover sauce. If you wish to use the chashu sauce, be sure to strain it first. Prick the egg with a pushpin at the larger, rounded end, to prevent the eggs from cracking while they boil. Add in the 50ml of rice vinegar, bring to a boil, then boil the eggs for 6-7 minutes. However, for the first 60 seconds, gently stir the eggs clockwise, and counterclockwise, back and forth in the pot. This will center the yolk of the eggs. After the eggs have finished cooking, place them into an ice bath to stop cooking process. Marinate the eggs in the chashu sauce and store them in a container in the refrigerator overnight, up to 2 days. By placing a paper towel over the marinade, it keeps the eggs from floating up and helps the eggs to be more evenly marinated. Below is a picture of one egg, sliced in half that had been marinating for 24 hrs. When slicing them, it helps to use fishing wire for a cleaner cut.

VERY IMPORTANT: Now, this is the trick to further whitening and thickening the tonkotsu broth!…Once the stock is 1 hour from being completed, scoop out about 750g of the meat, fat, garlic, and some of the soup stock for easier blending; avoid picking out the tough bones! Place them in a blender on the “smoothie” or “grind” setting. Add the liquidy paste back into the soup stock and stir with a whisk until blended in.

After the 12-15 hours are completed, you can finally strain the tonkotsu stock into a container. Allow the broth to cool before placing in the refrigerator overnight. By cooling overnight, the flavors get more time to meld.

Day 4: Ramen Completion Day (“SUNDAY”)

The broth should be like the consistency of a super thick gravy once it has chilled.

BUILDING YOUR BOWL OF RAMEN: For any other toppings you that wish to use, have them already out and prepared. Once you start heating up the broth and boiling noodles, you must work carefully and quickly to assemble your bowl of ramen and to not let the noodles soak for too long in the hot broth. A bowl of ramen should be eaten within 5-10 minutes after it has been made and served.

• Slice in half one ajitama, then reheat some chashu slices by your method of choice: pan-searing, butane torch, etc.
• Bring to a boil 300ml of tonkotsu soup stock in one saucepan, and the water needed to boil your noodles in another pot.
• Add into your ramen bowl, 75 ml of tare.
• Boil your noodles. If you are using Hakata-style noodles, they should only take a few minutes to boil. However, be sure to follow the package instructions for best results.
• Add the soup stock to the bowl, and then add in your noodles.
• Quickly top your ramen bowl with chashu, ajitama, (green onions, menma, benishouga, karashi takara, lard oil, etc.)


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