VOL.198 NOVEMBER 2024
JAPANESE RAMEN AND ITS GLOBAL EXPANSION Scientifically Breaking Down What Makes Japanese Ramen So Delicious

Bowl of tonkotsu ramen

Japanese ramen has been enjoying increasing popularity among visitors to Japan from other countries. Ramen in Japan comes in a diverse range of varieties, with main styles including shoyu, miso, shio, and tonkotsu (table below), as well as noodles of varying thicknesses, regional variations featuring special local ingredients, and more. Around 18,000 ramen restaurants* are found in Japan, and over the last 15 years or so, more and more ramen restaurants have been opening up overseas, as well. What secrets have made ramen such a worldwide sensation? We interviewed YONEMITSU Muneaki, a professor in the Faculty of Life Science at Kyushu Sangyo University who conducts research on tonkotsu ramen, to gain more insights from a scientific perspective.

Recently, Japanese ramen has been enjoying widespread popularity even overseas. Could you start by sharing some insights into what makes this dish so delicious from a scientific perspective?

One basic factor in what makes foods appealing to people is balance, and this is not limited to ramen alone. For example, the level of salt concentration that makes food taste good to people tends to fall in the same general range. No matter what type of food, if the concentration is not within that range, it will tend not to taste good. This can be traced to the salt concentration of the cells that make up the human body, which is about 0.9%. At around that level, foods have an appealing flavor. Incidentally, salt concentrations of about 0.9% are also the same for saline solutions used for cleaning contact lenses, for example, and isotonic sports drinks. Having this same level of concentration also makes them easier for the body to absorb.

Other components of human flavor include amino acids such as peptides and saccharides. These elements are also essential to our bodies. Eating sweet things must give people a pleasant feeling because, as living beings, we have evolved through experience to sense that eating foods with sugar content gives us energy. This pleasant feeling serves as the motivation to eat foods that contain saccharides.

Umami, one element said to be a particular key to appealing flavor, is related to glutamic acid, one of the main amino acids of protein. As it is a nutrient necessary for creating muscle in living things, it gives people a pleasant feeling when they eat foods containing it.

These are some of the mechanisms that make foods appealing to people, and they do not tend to vary depending on people’s ethnicities or the regions where they live. With the umami-rich flavor ramen has from its dashi broth and its salt concentration that feels just right, it is actually not so surprising that it has been accepted to such a degree worldwide. Different countries and regions do have their own food cultures, however, and I think ramen’s status as a novel dish not originally found in those particular cuisines can also give it a special appeal.

Savory tare (or kaeshi) sauce is combined with a dashi broth before boiled noodles are added to prepare a bowl of ramen.

What makes tonkotsu ramen, the focus of your own research, unique compared to other types of ramen?

Ramen in Japan falls into several categories including shoyu ramen, miso ramen, shio ramen, and tonkotsu ramen. However, that is actually not a precise classification. Fundamentally, the broth the ramen noodles are served in is made from savory sauces made from tare — also known as kaeshi — and dashi. Now, dashi corresponds to a type of broth or stock you might know as a fond** from Western cuisine. Typically, a smaller amount of tare might be added to the bowl and dashi added to it to create the broth before boiled ramen noodles are added to it. The ratios often vary from one restaurant to another.

This tare sauce is a primary element in determining the flavor of the ramen, from soy sauce-based shoyu to miso or shio. Classifications like shoyu ramen, miso ramen and shio ramen are based on the type of this main ingredient, the tare. Tonkotsu ramen, on the other hand, is defined by its dashi broth which is typically cloudy, made by boiling pork bones — tonkotsu in Japanese —at high heat. I will explain more about this, but this type of ramen is not defined by the type of tare sauce used.

Classification of Ramen and Types of Tare and Stock

Only tonkotsu ramen is defined by the characteristics of its dashi
Materials: Provided by Prof. YONEMITSU

Only tonkotsu ramen is named after the characteristic of its dashi broth, right?

Yes. The shoyu ramen and miso ramen styles most commonly found in the Kanto region typically feature clear broth bases that are gradually simmered at low heats to prevent cloudiness. Tonkotsu ramen, on the other hand, features a broth base that is boiled hard. This makes a cloudy broth through emulsification: creating a stable mixture of the liquid and fats and oils contained in pork bones or chicken bones. This process brings the flavor to the forefront, giving tonkotsu ramen its characteristic richness and flavorful, one of the key points to what makes it taste so appealing.

Methods of preparing tonkotsu ramen vary from one restaurant to another, from the parts of bones used to the way broth is extracted from them, to how the foamy layer of scum that develops on top of the boiling broth is dealt with. These factors all affect the flavor and style of the broth. Another factor is whether thin noodles that easily absorb the flavor of the broth are used or flatter noodles that provide richer enjoyment of their texture. This will affect the flavor as well. Still another factor is whether the tonkotsu broth is combined with soy sauce-based shoyu tare or miso. All of these factors and combinations can completely change the overall flavor. There are limitless variations to enjoy.

So, with tonkotsu ramen, it seems that individual restaurants are choosing what they consider to be the best combinations of various factors: the parts of bones used in making the broth, the thickness of the noodles, the type of tare sauce, and so on. Is there anything like a formula or principle that applies to this?

In having conversations with chefs who are actually preparing ramen, I find that they have all found the best solutions for their individual restaurants drawing on their years of experience and intuition. However, as a researcher, I would like to scientifically clarify this combination so that it can be explained clearly.

I understand you have also been involved in developing types of instant noodles outside Japan in the past. What kinds of ramen did you find appealed to people in those other countries?

In the past, I worked as a technical expert for a Japanese food manufacturer establishing operations and developing types of instant noodles in countries including Poland, Thailand, and Peru. In Poland, for instance, I researched what type of broth was most commonly enjoyed in the country. That turned out to be a broth made with mushrooms and tomatoes, so we developed instant noodles with a broth base featuring that flavor. Originally, many exchange students from Vietnam went to study in Poland as part of the Comecon*** economic policy, and they brought a lot of instant noodles with them. Polish people came into contact with instant noodles through them, and it came to be a common, widespread item that way.

Backgrounds like that must have made it easier for Japanese ramen restaurants to expand overseas, as well.

Yes, true. There were already Japanese ramen restaurants around when I was in Europe in the early 2000s. These restaurants, however, tended to have local management, rather than Japanese. I remember that later when ramen restaurants opened in major Western cities including New York and London, their popularity really increased. Considering this series of events, I would suggest that ramen has gradually increased in worldwide popularity since shortly after 2000, rather than saying that a ramen boom has taken off all of a sudden more recently.

What are some ways you think ramen and its popularity might evolve further in the future, both in Japan and overseas?

While I do think we can certainly expect the Japanese dish of ramen to continue becoming more widespread around the world, I also wonder if we might start to see more new types of ramen matched to the food cultures of various other countries. In areas where halal**** dietary restrictions are observed, for example, ramen that is tonkotsu-flavored but not made from pork bones is becoming more common. I think we might see more and more new versions like this, such as ramen suitable for vegans***** and styles based on regional cuisines.

So, it seems that ramen might take on different forms as food cultures become increasingly diverse. Could you finish up by sharing how our readers from outside Japan might get even more enjoyment out of Japanese ramen?

As I just mentioned earlier, different countries have different food cultures. One major difference between Japan and other countries is the presence of a “slurping” culture. Making sound when slurping up noodles has been considered bad manners in Western cultures. When you slurp ramen noodles, sipping in the broth together with the noodles in this way, however, the delicious flavor of the dish really spreads in your mouth. I want to recommend trying not to be shy about it. Go ahead and slurp your ramen like this. I can tell you that, when you could do this, a whole new frontier of flavor will open up for you, unlike anything you have experienced before.

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* The number of “ramen restaurants” under “Service Industries B, Tabulation of Individual Industries” in the 2016 Economic Census for Business Activity
** In French cuisine, a broth or stock made from ingredients such as veal bones and muscles. Used as a foundation for sauces and stews.
*** Abbreviation of the Council for Mutual Economic Assistance, an international organization established in 1949 with the aim of promoting economic cooperation between the Soviet Union and socialist countries in Eastern Europe. Members included countries from other parts of the world as well, such as Mongolia, Cuba, and Vietnam. Comecon dissolved following the collapse of the Soviet Union.
**** Guidelines concerning all aspects of life for Muslims. In terms of dietary restrictions, foods and drinks including pork and alcohol are forbidden.
***** People who follow a completely vegetarian and dairy-free diet, avoiding all types of animal-derived foods.
****** A version of ramen re-creating the flavor of tonkotsu broth using only plant-based ingredients. In place of the grilled pork that typically tops the dish, vegan meat made primarily from soybeans is used.

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By MOROHASHI Kumiko
Photo: Kyushu Jangara; Provided by Prof. YONEMITSU; PIXTA