Tonkotsu (豚骨), or pork bone broth ramen, is the most popular style of ramen outside of Japan, known for its thick, creamy, savoury soup stock. While tonkotsu ramen is usually attributed to the Hakata style popularised by global chains like Ichiran and Ippudo, not many people know that the origin of this version of ramen is an even richer style that arose purely by accident, or so the story goes, before spreading rapidly throughout the entire western island of Kyushu. This is Ramen 131: Kurume ramen, the serendipitous origin of tonkotsu ramen.

Table of Contents

History of Tonkotsu Ramen – The Science of Cloudy Soups Components of Kurume Ramen – Soup – Noodles – Toppings The Shops Where We Ate

History of Tonkotsu Ramen

People are constantly creating new kinds of ramen, though for a long time it was very broadly grouped in 4 categories: shio (塩, salt), shoyu (醤油, soy sauce), miso (味噌), and tonkotsu (豚骨, pork bone). The first 3 are defined by the way the soup is seasoned, while tonkotsu refers to the soup base itself, a cloudy, creamy, pork bone broth. Before cloudy broths were a thing, ramen used to be more aligned to the clear Chinese styles of soup, made by simmering meat bones low and slow, and it had been that way since the earliest conceptions of ramen over 100 years ago. Ramen soups were made with chicken or pork bones, and sometimes seafood like fish or konbu seaweed, and seasoned using salt or soy sauce in the form of tare (たれ), but all the soups were transparent. Ramen captured the hearts of many people because it was cheap, fast, and delicious, the perfect food for the working class, and gradually spread throughout the country.

Cut to 1935. In the city of Kurume in the Fukuoka Prefecture, an udon chef called Tokio Miyamoto (宮本時男) decided he wanted a cut of the action. He moved to Yokohama to learn the craft, and in 1937 came back to Kurume City to open up the first ramen store in the whole island of Kyushu. This stall he called Nankin Senryo (南京千両), and supposedly influenced by his Nagasaki roots, he took inspiration from another Chinese dish called champon (ちゃんぽん) and used primarily pork bones in his broth. Unsurprisingly, ramen became popular in Kyushu for the same reasons as in Tokyo and Yokohama, spreading to the neighbouring cities rapidly.

Ramen soup at this stage was still clear. It wasn’t until 10 years later in 1947 when Katsumi Sugino (杉野勝見), the chef of a ramen restaurant called Sankyu (三九), made the fateful mistake of taking his eyes off his boiling pot of stock. Legend has it he asked his mother to watch the pot, and she had let it come to a rolling boil and left it, rather than lowering it down to a simmer. Though horrified, he had no option but to try it as it approached opening time, and found to his surprise that it was, in fact, delicious.

The Science of Cloudy Soups

Cloudiness in soups is the result of a process called emulsification. This is when two liquids that normally don’t mix – e.g., water and oil – are combined in such a way that they dissolve into each other uniformly. This can be done using emulsifiers, where an additive with both water- and fat-soluble components helps the two liquids to mix such as egg yolks in the case of mayonnaise, or by mechanically breaking up the fats, which is essentially the process of milk homogenisation.

For soup stocks cooked barely at a simmer, you’ll end up with the main broth, and probably a layer of fat floating on top, because these two layers don’t mix. However, when soup is left at a rolling boil, the heat combined with the movement of the bubbling water extracts the fats and proteins from the bones and breaks them up into microscopic droplets in the water. This results in a cloudy soup stock for the same reason that milk is cloudy from fats and proteins.

Katsumi Sugino went on to teach the process of making tonkotsu broth to anyone who wanted to learn, which caused it to spread rapidly throughout Kyushu. This gave rise to variations such as Hakata, Kumamoto, Kagoshima, and Tamana ramen. Subsequently came the huge rise of chains such as Ichiran, Ippudo, and Ajisen, which spread throughout the world and solidified the concept of ramen that most of us outside of Japan know it as today.

Components of Kurume Ramen

Not all Kurume ramen have the same components, but these are fairly typical. for this style.

Soup

The key difference between Kurume ramen tonkotsu and virtually every other tonkotsu is in the broth. Kurume ramen broth is made using a process called tsugiashi (継ぎ足し) or yobi-modoshi (呼び戻し), which can be translated as “splicing” (yes, like as in DNA). While most ramen stores will make a new pot of broth every day from fresh water and raw ingredients, Kurume ramen will take the leftover broth from the day before and add this to the next batch of soup stock. This is much like the process of sourdough.

According to a food research laboratory in Japan, this results in significantly higher levels of umami compounds such as glutamic acid – up to 3 times that of normal tonkotsu ramen broths that are made fresh daily. This makes Kurume broth the richest and most unique-tasting style of ramen despite usually being less greasy than other styles of tonkotsu, with some ramen restaurants having soups that are decades old.

Noodles

Kurume Ramen usually comes with medium-thin, straight-ish noodles. It’s thicker than the ultra-thin Hakata ramen noodle, and often a bit softer in texture but still with a toothsome bite in the centre. The portion of noodles is standard at about 140-150 g per portion, and while you can order kaedama (替え玉, extra portion of noodles), it’s not common for every Kurume ramen restaurant.

Toppings

Standard toppings for Kurume ramen are typically a slice of chashu pork, some green onion, and kikurage wood ear mushrooms. Boiled eggs and nori seaweed are popular additions. Depending on the store, you may find things like garlic and pickled ginger either already in the soup or as condiments at your table. In the neighbouring Saga prefecture, it’s not uncommon for a raw egg to be added to the ramen for a milder, creamier soup. This is normal and perfectly hygienic in Japan.

The Shops

There is no shortage to choose from when you’re looking for Kurume ramen shops in Kurume city.

Nankin Senryo is a popular destination for ramen fanatics as the first ramen shop in Kyushu. The store is still in operation, though they have curlier, thicker noodles as the store predates the creation of tonkotsu ramen. Sankyu, the creator of the tonkotsu style, has since moved from Kurume.

You can’t talk about Kurume ramen and not mention Maruboshi (丸星) and Maruko (丸幸). Maruboshi opened in 1958, and Maruko in 1965, both famous stores that sit along the National Route 3 Highway between Fukuoka City and Kurume City, making them popular rest stop destinations for truckers and travellers. Both used to be open 24/7, with Maruboshi being the first known ramen shop in Japan to be open 24 hours.

For many others, you can refer to the Kurume tourism page for Kurume ramen, so don’t feel pressured to go out of your way to visit famous restaurants. Other big players include:

• Hirose ひろせ食堂
• Seiyoken 久留米ラーメン清陽軒 本店
• Taiho 大砲ラーメン – which had a long-running store at the Shin-Yokohama Ramen Museum
• Honda Shoten 拉麺 久留米 本田商店

Where We Ate

We decided to pay a visit to Maruboshi simply because of its institutional status within the ramen world. However, we wouldn’t necessarily recommend it as a must-visit – not because of the quality of the food, but rather because of the difficulty in getting there. It’s about 15 minutes’ bus ride from Kurume train station, with inconsistent bus schedules, meaning it can be tricky to visit unless you’re driving in.

Maruboshi is spelled using the kanji characters for round/circle (丸), indicating the sun (daytime), and star (星), indicating nighttime, alluding to its 24/7 opening hours. Since Covid, they’ve reduced their opening time to 12 hours a day, 6 days a week, which is still a lot. While they’ve done some work to refresh their iconic yellow awnings, it’s unmistakable that they’ve been around for decades. Photos and signatures of celebrities cover every inch of the walls, alongside retro movie posters, the decor understated and completely unpretentious. Their menu is small, offering one type of ramen in various sizes, a few simple side dishes, and a selection of oden, or stewed ingredients.

Everything seems aligned to customer satisfaction and accessibility, the portions generous and the prices dirt-cheap – known for their ¥400 ramen bowls, they worked hard to stave off price increases until the economy forced them to increase their pricing several times until it landed on ¥550 per bowl. This is still beyond respectable, especially when they fought to protect their customers from absorbing rising costs. Even now, they seem to have sought out alternative streams of income, selling merchandise in the form of T-shirts, pins, and stickers, and even have their own instant noodles just to stay afloat.

It’s why we implore any visitors to be conscious of small independent restaurants, particularly in the case of Maruboshi, who even still offers a selection of free side dishes to help yourself to. Take what you need, and be mindful about the resources you use up, whether that’s time, space, or physical things like napkins. Do your best to observe the etiquette of eating ramen, but also don’t forget to enjoy your meal.

The yellow signage might be visible from some distance away, but the thick smell of pork wafts through the neighbourhood before you can figure out where the entrance is. It’s quite a strong smell, and due to the style of broth, it’s definitely not suited for every palate. Ordering is done through ticketing machines. The restaurant only has table seats, and waiters are positioned to seat you, take your ticket, and bring you your order, though side dishes and water are self-service. Keep in mind that this busy little eatery is not going to uphold the typical level of customer service, so it may not be as prompt or efficient as other places might be. Our ramen came about 2 minutes apart (incredibly long for ramen!), though it did give us time to muck around with photos and filming before the second one came.

One bowl comes with a slice of rolled chashu pork, some green spring onions, and a small sheet of nori seaweed. The broth is incredibly thick, the fats well-emulsified into the soup stock rather than sitting on top, though it leaves a sheen on the lips that could easily replace lip gloss. When we describe this soup as piggy we aren’t exaggerating – this soup stock hit us very hard and very fast, the moment a sip is taken. Beneath layers of savoury pork is a distinct stink of pig, which will be delicious to some, and completely unpalatable to others. Whether this is for you is not up to us to decide. It’s not a bowl we would imagine people draining down to the last drop, though plenty have done it. That’s all we can say about the ramen, because the flavour is certainly the focal point. The chashu is tender. The portion is filling. The side dishes are great as a break from the soup, though condiments or some tea would do the trick just fine. It’s a satisfying and hearty bowl, which means Maruboshi achieves exactly what they promise to deliver. All is well in life.

We would recommend a visit to Maruboshi if you don’t mind a bit of travelling, and if you want to pay a visit to an iconic shop that we would encourage supporting. Whether it’s a must-visit is up to you, seeing as there are plenty of famous stores closer to the station and easier to access, but we wouldn’t have changed our experience.

Final Thoughts

As much as we love and enjoy ramen chains, it was great to have been able to experience its roots and taste what ended up being our most jaw-droppingly unexpected ramen in Japan. This was especially true as we continued our journey through Kyushu, trying different variations of tonkotsu ramen – which you’ll have to stick around for!

The information in this post is also viewable as a YouTube video at the top of the page.

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