What is Mochi-gatsuo?

A photo of Modori-gatsuo
Modori-gatsuo are those that migrate southward from off Sanriku to the Boso Peninsula from mid-September to late October.

In Japan, bonito is called variously Hatsu-gatsuo, Modori-gatsuo, Mayoi-gatsuo, Netsuki-gatsuo, and so on. The quality of the fish is unique depending on the season and size, and bonito lovers will be able to enjoy a variety of flavors throughout the year. Now, bonito, a popular fish since the Edo period, has recently been given a new name, Mochi-gatsuo, which we have never heard of, and we would like to dig deeper into it.

A photo of bonito
The quality of bonito cannot be determined until it has been sliced.

As a general rule, one cannot identify a bonito just by looking at it, and even marketers and sushi chefs cannot tell its quality until they try to slice it. In particular, Hatsu-gatsuo (Nobori-gatsuo) has greater individual differences than Modori-gatsuo (Kudari-gatsuo), and may even be inedible raw due to its distinctive odor. It is called Ishi-gatsuo or Gori-gatsuo. Its flesh is noticeably firmer than normal fish in terms of elasticity. Its flesh is white, pink, or brownish. It also smells very bloody, almost like iron. The cause is currently unknown.

Because of its high hemoglobin and myoglobin content, bonito has a stronger bloody smell than other fish, even if it is not fresh. This richness is due to the high content of nitrogen compounds such as creatine and histidine, in addition to the umami substance inosinic acid. This is the reason for the unparalleled love of bonito.

A photo of Kenken gatsuo
The fishermen in the town of Susami, Wakayama Prefecture, immediately ikejime each bonito they catch on board, drain the blood out of the fish, and bring it back to the port in a container with its head in seawater ice.

On the other hand, bonito is a representative fish that loses its freshness quickly and is usually flash-frozen immediately after being caught. However, thanks to the tremendous efforts of fishermen, we can now eat fresh bonito. For example, fishermen in the town of Susami, Wakayama Prefecture, immediately ikejime each bonito they catch on board, drain the blood out of the fish, and bring it back to the port in a container with its head in seawater ice for the day’s auction. Kenken-gatsuo is the result of thorough techniques for preserving freshness. The same is true of Taru-gatsuo from Hachijojima Island in Tokyo, for example. However, by the time the raw bonito arrives at the sushi restaurant to be made into Nigiri sushi, 12 hours have passed since the fish was caught. This time is critical to the quality of the fish.

So what kind of bonito is Mochi-gatsuo?

Hatsu-gatsuo has a refreshing, spring breeze-like flavor. Some of them are called “Mochi-gatsuo”, a type of bonito whose flesh is elastic and has the texture of freshly pounded rice cakes. Originally, bonito is caught far offshore, but in the spring, it comes much closer to land, so it can be brought to port before it becomes rigor mortis. Not all bonito are Mochi-gatsuo, however, and only a few are part of the same school, making them extremely rare. According to one theory, they are eaten before rigor mortis, which occurs four to five hours after the catch. Its season is from March to June, and it is consumed locally, as it is difficult to ship to distant places.

The name is also wonderful, as it compares the flesh of the bonito to a Mochi (rice cake). So far, the name “Mochi-gatsuo” is only used in Wakayama and Shizuoka regions. If you have a chance, you would like to try it.

Related contents:

Bonito (Katsuo)

Quality Improvement of Frozen Bonito


A photo of bonito sashimi
Frozen bonito begins to mature after thawing.

Large fishing vessels sail the Pacific Ocean year-round in pursuit of bonito (Skipjack tuna). The fishing method is divided into pole-and-line fishing and purse seine fishing. Pole-and-line fishing involves spreading live bait such as Japanese anchovy to attract schools of skipjack tuna, which are then caught in large numbers with the rod in a short period. Because of the need to keep live bait for a long period, this fishing method was limited to the waters around Japan for many years. Still, recent technological advances have also made pole-and-line fishing possible in southern waters.

The bonito caught in the waters around Japan is called Higashi-no-mono. This follows sardines and other fish that serve as bait and come north from the waters around the Philippines. The bonito called Nanpo-mono also approaches the waters around Japan from off Micronesia and other areas. This one is mainly caught by large vessel purse seine fishing. In purse seine fishing, the bonito rub against each other before being hauled on board, easily damaging the flesh. As a result, the fish may be less fresh and damaged than when caught pole-and-line fishing.

Vessels that take skipjack are equipped with sophisticated refrigeration facilities. There is a pool of brine solution, a salt solution with a concentration of about 20%, on board. The flash-frozen skipjack is called B1. After being thawed and filleted, the fish is rigor mortis, which means it is extremely fresh and is distributed as high-quality frozen skipjack for raw consumption. Of course, they are also very expensive. In addition, when caught, the blood is removed and the fish is flash-frozen, called S1, and is distributed as a higher quality product than B1.

Only carefully selected skipjack and those frozen under strict freezing conditions are marketed as B1, while skipjack that is frozen in the same freezer but not according to B1 standards is distinguished from B1 and referred to as B. Incidentally, B1 and B are caught by pole-and-line fishing. There is another type of frozen bonito called PS. This is not caught by pole-and-line fishing but by purse seine fishing. It is not in as good condition as pole-and-line fishing, but it is handled with care and has few scratches.

In summary, Bonito (skipjack) originally deteriorated quickly and was difficult to distribute fresh, but improvements in freezing technology and other factors have ensured that the quality is close to fresh.

How is the taste of vinegar determined?

A photo of Rice vinegar
The vinegar used for Vinegared rice is basically rice vinegar or red vinegar. Mizkan, which contributed greatly to the development of Edomae sushi, is still a famous vinegar manufacturer.

When we think of vinegar, a sour taste immediately comes to mind, but vinegar is not only sour, it also contains a variety of ingredients and has a mild taste. There are also many different types of vinegar, each with its unique flavor. Just as beer is made from barley and wine from grapes, vinegar has a variety of flavors, aromas, and richness depending on the ingredients.

Acetic acid is the predominant acidity, with other organic acids such as gluconic and citric acid also present. It also contains lactic acid, succinic acid, tartaric acid, malic acid, and citric acid, each with a different taste. Lactic acid has an astringent taste, while citric acid has a refreshing sour taste. These mix to form a complex sour taste. Adding even more variety to the sourness are the ingredients that the raw materials originally contained, such as sweetness, umami, richness, and aroma. Rice vinegar is particularly rich in carbohydrates and proteins, while black vinegar is rich in amino acids and various organic acids. These diverse flavors combine to create the flavor of vinegar.

By the way, we believe that what is required of vinegar used for sushi rice (vinegared rice) are two contradictory characteristics: refreshing and full-bodied. When sushi chefs prioritize richness, they use red vinegar or black vinegar with high amino acid content. However, this is a far cry from the light and refreshing taste that was originally sought in nigiri sushi. Therefore, sushi chefs try to solve the contradictory problem by mixing kinds of vinegar.

Various studies have also found amino acids such as glutamic acid, peptides, fat, glycogen, and alliin as substances that strengthen the richness. To make delicious nigiri sushi, the ingredients of sushi toppings and condiments must also be taken into consideration. It is not enough to focus only on vinegar. Of course, sushi chefs are not food researchers, so they have never conducted a quantitative analysis of amino acid content.

According to papers on the taste of vinegar by Masao Fujimaki, professor emeritus at the University of Tokyo, Ryuzo Ueda, associate professor at Osaka University, and Hiroshi Masai of Mizkan, amino acids exhibit a variety of flavors and are closely related to the unique taste of various foods. It is said that there are more than 20 kinds of amino acids that make up proteins, and 17 kinds of free amino acids exist in vinegar, which affects the taste of each vinegar.

The papers on the taste of vinegar

Rice vinegar is composed mainly of more than 10 amino acids, including glutamic acid, arginic acid, and aspartic acid. Among them, glutamic acid produces a delicious taste. Glutamic acid not only makes vinegar tasty but also works synergistically with the umami component to make nigiri sushi even tastier. Furthermore, the amino acid also acts on the slight sweetness of the vinegar and makes the overall taste milder and milder. In this respect, it can be said that the taste of rice vinegar is determined by the amount of amino acids present in the vinegar.

Although the amount of rice used as a raw material and the characteristics of the alcohol added during the production process are also important factors in increasing amino acids, at least standing fermentation (or static Fermentation) is a particularly important condition. Therefore, we surveyed Japanese vinegar manufacturers that use standing fermentation. Many sushi chefs use these vinegars. However, which vinegar is used as the main ingredient and what it is mixed with is, of course, a trade secret. And for fish preparation, vinegar made from brewing alcohol and containing almost no amino acids produced by fast fermentation is more refreshing. Again, it is not just a matter of focusing on the amount of amino acids.


List of Japanese Vinegar Manufacturers using Standing fermentation

Marusho vinegar (合名会社 丸正酢醸造元)

Establishment: 1879

TEL: +81-735-52-0038

Address:271 Tenma, Nachikatsuura-cho, Higashimuro-gun, Wakayama prefecture 〒649-5331

HP: Marusho vinegar

#standing fermentation


Kobara vinegar (合名会社 河原酢造)

Establishment: 1823

TEL: +81-779-66-3275

Address:8-25 Yoshi, Ono-shi, Fukui prefecture 〒912-0401

HP: Kobara vinegar

Products: Yuuki Junmai vinegar Robai

#standing fermentation


Totsuka Vinegar Brewery (戸塚醸造店)

Establishment: 2005

TEL: +81-554-56-7431


253 Natsukari, Tsuru-shi, Yamanashi prefecture

HP: Totsuka Vinegar Brewery

#standing fermentation


Okuno zyouzou (株式会社 奥野醸造)

Establishment: –

TEL: +81-224-51-8891

Address:44 Aza Hayashi, Oaza Irimada, Shibata-cho, Shibata-gun, Miyagi prefecture 〒989

HP: Okuno zyouzou

Products: Junmai vinegar

#standing fermentation


Tobaya vinegar (株式会社とば屋酢店)

Establishment: 1710

TEL: +81-770-56-1514

Address:6-2, Higashiichiba 34, Obama City, Fukui Prefecture 〒917-0232

HP: Tobaya vinegar

Contact: support@tobaya.com

Products: Junmai brewed vinegarTsubonosu

#standing fermentation


Takano vinegar (株式会社高野酢造)

Establishment: –

TEL: +81-76-273-1188

Address:103, Tsurugi Okuni-machi Ho, Hakusan City, Ishikawa prefecture 〒920-2133

HP: Takano vinegar

Contact: https://takano-su.co.jp/inquiry/inquiry.php

Products: Hakubai

#standing fermentation


Tankai vinegar (淡海酢有限会社)

Establishment: –

TEL: +81-740-36-0018

Address:1403 Katsuno, Takashima-shi, Shiga prefecture〒520-1121

HP: Tankai vinegar

Products: Rice vinegar Ginjo

#standing fermentation


Mikura vinegar (株式会社トーエー)


TEL: +81-5979-3-1660

Address: 2266 Atawa, Mihama-cho, Minamimuro-gun, Mie prefecture 〒519-5204

HP: Mikura vinegar

Contact: https://mikurasu.jp/en/contact

Products: White Vinegar Gekka, Red Vinegar Akane

#standing fermentation


Onomichi vinegar (尾道造酢株式会社)

Establishment: 1582

TEL: +81-848-37-4597

Address: 1-5-2 Kubo, Onomichi City, Hiroshima prefecture 〒722-0045

HP: Onomichi vinegar

Contact: https://kakuhoshisu-onomiti.com/contact.php

Products: Rice vinegar, Pure Red vineager

#standing fermentation


Imakawa vinegar (今川酢造)

Establishment: 1923

TEL: +81-76-241-4020

Address: 3-19-1 Nomachi, Kanazawa City, Ishikawa prefecture 〒921-8031

HP: Imakawa vinegar

Contact: https://www.imakawa.com/inquiry/

Products: Marusan Junmai vinegar

#standing fermentation


Iio Jozo (株式会社飯尾醸造)

Establishment: 1893

TEL: +81- 772-25-0015

Address: 373 Odasyukuno, Miyazu-shi, Kyoto-fu 〒626-0052

HP: Iio Jozo

Contact: fujisu@iio-jozo.co.jp

Products: Pure rice vinegar Fujisu, Pure rice vinegar Premium

#Stationary fermentation


Yokoi vinegar (横井醸造工業株式会社)

Establishment: 1937

TEL: +81- 3522-1111

Address: 4-2-17 Shinkiba, Koto-ku, Tokyo 〒136-0082

HP: Yokoi vinegar

Contact: https://yokoi-vinegar.com/contact-us

Products: Kinsho etc.

#standing fermentation


Kisaichi Brewing (私市醸造株式会社)

Establishment: 1922

TEL: +81- 47-443-2511

Address: 6-7-45 Higashi-Michinobe, Kamagaya-shi, Chiba prefecture 〒273-0115

HP: Kisaichi Brewing

Contact: https://kisa1.com/contact/

Products: THE EDOMAE Sushi vinegar

#standing fermentation


Murayama vinegar (村山造酢株式会社)

Establishment: about 1720

TEL: +81-75-761-3151

Address: 3-2, Ohashi Higashi-iru, Sanjo-dori, Higashiyama-ku, Kyoto 〒605-0005

HP: Murayama vinegar

Products: Chidori

#standing fermentation


Mizkan (株式会社 Mizkan)

Establishment: 1804

TEL: +81-569-21-3331

Address: 2-6 Nakamura-cho, Handa, Aichi prefecture 〒475-8585

HP: Mizkan

Contact: https://www.mizkanholdings.com/en/inquiry/

#standing fermentation


Kokonoesaika (株式会社九重雜賀)

Establishment: 1908

TEL: +81-736-66-3160

Address: 142-1, Momoyama-cho Moto, Kinokawa-shi, Wakayama prefecture 〒649-6122

HP: Kokonoesaika

Contact: https://kokonoesaika.co.jp/contacts/

Products: Saika Ginjo Red vinegar

#standing fermentation


Koutarou vinegar (有限会社林孝太郎造酢)

Establishment: –

TEL: +81-75-451-2071

Address: 455 Michimasa-cho, Higashi-iru, Teranouchi-agaru, Shinmachi-dori, Kamigyo-ku, Kyoto-shi, Kyoto 〒602-0004

HP: Koutarou vinegar

Products: Rice vinegar

#standing fermentation

Related contents:

Types of vinegar

What is Edomae sushi?

A photo of Edomae sushi (Nigiri sushi)
Edomae sushi (Nigiri sushi) in the Edo period was about twice the size of today’s sushi.

We recently read a sushi article in one of the Food media and were amazed that there are still media outlets out there that are so misinformed. If taken dispassionately, it may be a reprinted article or an article created by a generated AI. Also, food writers who use arguments like “I live in Japan” or “I know sushi well because I have been to over 500 sushi restaurants” are not to be trusted in their articles.

Nigiri sushi originated about 200 years ago, but in fact, it can be said that no book comprehensively describes it. The only information available is the diaries of the samurai and aristocrats of the time, which are only a few lines of text. As proof of this, it is not even certain who started making nigiri sushi, and there are many theories. In other words, there is a possibility that it has been rewritten to suit their convenience.

Depending on whether sushi is classified in terms of its history or terms of its production method, the types of sushi will naturally differ. If we discuss in a confused state, we will not reach a single conclusion. Vinegar was produced by the natural fermentation of fish and grains for preservation purposes. This is the form of sushi when it originated. It must have originated in China, Southeast Asia, or somewhere in between. In Nigiri sushi, however, vinegar made from sake lees or other ingredients is added to cooked rice. Even if we focus the argument only on vinegar, there is no way to say that they are both the same food.

This article was rudimentary in that there are several types of sushi, including Nigiri sushi, Maki, Roll sushi, Inari sushi, Chirashi sushi, and Sashimi. As you already know, Sashimi is not a type of sushi. It is a typical Japanese dish. And this misunderstanding of Sashimi leads to a wrong understanding of Nigiri sushi. No one does not know what Nigiri sushi is. However, many people think that Nigiri sushi is Sashimi on top of vinegared rice (sushi rice). This is also a big mistake. Sushi topping can be made of vegetables or seafood, but without vinegared rice, it is not Nigiri sushi. We would like to remind you of this.

Moving on to our main topic, you may not have heard of Edomae sushi. It refers to Nigiri sushi, which originated in the Edo period (1603-1867), and although there have been some changes in the sushi ingredients, everything else has remained the same as when it originated. Together with maki sushi, which originated about 50 years later, it is now called Edomae sushi. The reason for the name “Edomae” is explained below.

Why is it called edomae?

So, except for the maki sushi story, Edomae sushi means Nigiri sushi. At the time when Edomae sushi originated, there was no such thing as a refrigerator, so it was not possible to refrigerate sushi toppings. It was natural to treat seafood for preservation. For example, we boiled Kuruma prawn (Kuruma ebi) and simmered Japanese conger (Anago).

Sashimi is a small piece of seafood, raw, with only the skin and bones removed. On the other hand, in Edomae sushi, the Sushi ingredients are treated in some way. We think the simplest treatment is to sprinkle salt on the seafood. This is one of the basic cooking methods practiced around the world. However, when making Sashimi, basic salt is not used. For more information on other processing methods, please check below.

Types of edomae preparations

Horse mackerel (Aji) and Mackerel (Saba), which lose their freshness rapidly, were preserved by soaking in vinegar until 50 years ago. Recently, however, they are served as close to fresh as possible. Even today, some Aji and Saba are still vinegared, but they are rare.

After the Great Kanto Earthquake, the Edomae sushi chefs lost their workplaces and went to the countryside to look for work. However, the local people did not understand the need to go to the trouble of preparing fresh seafood, and they gradually began to use raw sushi topping. Nowadays, the use of raw sushi topping is the norm in rural areas of Japan. Even the concept of “Edomae sushi” does not exist in the regions.

Conveyor-belt sushi, now a mainstream segment of the sushi industry, uses raw sushi toppings to save time and effort in preparing them, in other words, to cut costs. Or perhaps it is because farmed fish is not suitable for aging. It may be because Japan has a culture that values freshness, and fish is unusually valued for its freshness compared to meat and vegetables. Salmon, the standard sushi topping in other countries, is also used raw. It is not sprinkled with salt to reduce excess water and odor components.

Strictly speaking, these are not Edomae sushi (Nigiri sushi). They are called Sashimi vinegared rice. If we may add one more thing, there has been a shift from processing for preservation to processing to bring out the umami.

For your information.

What does Hon in front of the fish name mean?

A photo of Bonito (Katsuo)

The tastiest and most highly utilized Katsuo are Ma-gatsuo and Hon-gatsuo.Anyone can tell a fish is a different species if it looks different. However, there are cases where the appearance is so similar that you can’t just inadvertently make a mistake. That is when there are several species and the difference in value is significant. In the past, the fish was used as a fish fraud, and even today it is often used as a substitute.

So, the marketer adds the prefix Hon (本) in the name of a fish or shellfish to avoid confusion with a substitute. One of the meanings of the Japanese word “hon” is “genuine,” so this may have something to do with it.

For example, Hon-zuwaigani refers to Zuwaigani, which has a shorter fishing season and a much higher price than Beni-zuwaigani. To avoid confusion with Beni-zuwaigani, which has a similar name, the Hon is added to emphasize the fact that it is Zuwaigani.


Other fish names begin with the letter Hon.

・Hon-mirugai is Mirugai clam (Mirugai). To avoid confusion with Shiro-mirugai, which was considered a substitute for Mirugai in the past, Hon is added to emphasize the fact that it is Mirugai. Recently, however, the catch of Shiro-mirugai has been decreasing, and the price of Mirugai has skyrocketed.

・There are five main types of tuna distributed in Japan, including Minamimaguro, Mebachi, Kihada, and Binnaga, of which Kuro (kuro means black)-maguro, the largest, is considered the finest. As the name suggests, half of the fish’s body is black from the back to the lateral line, so it is so-called.

About 2 million tons of tuna are caught annually worldwide, but Kuro-maguro is only about 1% of that amount. Originally, maguro meant Kuro-maguro, but other species (Mebachi, Kihada, etc.) are now distributed, and to distinguish them from Kuro-maguro, what was originally called maguro is now called Hon-maguro.

Aka-kamasu, also called Hon-kamasu, is considered the most delicious of the kamasu family and is sold at high prices in the market. On the other hand, Yamato-kamasu, also called Mizu-kamasu, is a little less tasty, and the name seems to be used to distinguish Yamato-kamasu from Aka-kamasu.

・The official name of the family Pandalidae called Amaebi is Hokkoku-akaebi. It is widely found from the coast of Hokkaido to Toyama Bay and the eastern coast of the Korean Peninsula. It is widely found from the coast of Hokkaido to Toyama Bay and the eastern coast of the Korean Peninsula.

・Akagai is simply called Tama, Hon-dama, Hon-aka, etc. in the Toyosu market. There is also a Bachi-akagai that is very similar to the Akagai, but its real name is Satogai, which is not as red as Akagai and is smaller in size. Satogai is often mixed in with hon-dama and are called Bachi-akagai from Bachigai (it means out of place).


Finally, some seafood uses both Hon and Ma.

For example, there are four species of bonito: Katsuo, Suma-gatsuo, Marusouda-gatsuo, and Hirasouda-gatsuo. The tastiest and most highly utilized Katsuo are Ma-gatsuo (katsuo) and Hon-gatsuo (katsuo).

For your reference.

What does Ma in front of the fish name mean?

A photo of Horse mackerel (Ma-aji)
Ma-aji is the most commonly caught and represented species of Japanese Aji species.

Fish names include scientific names, standard Japanese names, local names, and foreign names.

Scientific names are the scientific names of organisms. They are written in Latin for international uniformity. They are also listed in fish-illustrated books. Standard Japanese names are defined by the Ichthyological Society of Japan. Local names are various names given to one species in different regions. In addition, when looking at English and French names, they do not correspond to species as in the Japanese standard Japanese name, and it is not uncommon for different species to have the same English name, or for multiple species to be called by the same English name. It is rare in the world that each fish species has its standard Japanese name, as is the case in Japan.

In addition to standard Japanese names and regional names, fish names unique to the Japanese language are sometimes used. For example, you have probably heard of the fish named Aji (鯵). Then is Ma-aji (真鯵) a different fish?

Actually, they are the same fish. The “Ma” in the name of a fish or shellfish indicates that it is the most representative, the most superior, or the most valuable among the many related species. The Chinese character “真” means “genuine.

For example, a total of 146 species of horse mackerels have been identified, including Japanese scad (Maru-aji), Bigeye scad (Me-aji), White trevally (Shima-aji), Amberstripe scad (Muro-aji), Red Scad (Aka-aji), Roughear scad (Oakamuro-aji), Great trevally (Gingame-aji), and Torpedo scad (Oni-aji). Ma-aji is the most commonly caught and represented species of Japanese Aji species.

There are other fish names beginning with Ma, which are briefly introduced below.

Ma-iwashi (真鰯) is a representative of sardines (Katakuchi-iwashi, Urume-iwashi, etc.).

・Kaki refers to Ma-gaki (真牡蠣). Ma-gaki is in season during the cold season and is mostly farm-raised, but there is a type of Kaki that is in season during the summer. It is called Iwa-gaki (岩牡蠣) and is characterized by its larger shells and meat compared to Ma-gaki.

・Anago with high market value are Ma-anago (真穴子), Goten-anago (御殿穴子), and Kuro-anago (黒穴子), but it is safe to assume that most Anago used in sushi restaurants are Ma-anago.

Other Ma (真) include Ma-dai (真鯛), Ma-dako (真蛸), Ma-dara (真鱈), and Ma-hata (真羽太).


Which fish tastes better, farm-raised or wild-caught?

A photo of Natural fish

The answer to this question is obvious.

First of all, the most common argument goes something like this.

Some say that farm-raised fish are fatty, but the image of natural fish being superior has simply taken hold. Others say that farm-raised fish are raised in small fish ponds, so they are less active and less chewy, or that feeding them formula feed harms the taste and aroma of their meat. Well, all opinions can be said to be right or wrong.

It could be for the following reasons. It does not touch on the quality as well as the quantity of fat. Not all fish farms are small, and there are far more people who prefer soft flesh to chewy flesh. And we know that feed has a big impact, so formula feed has been greatly improved. It is all about the so-called superficial argument.

And as you probably know, there are fish of the same season, same species, and same freshness that are natural but separately not so tasty. It can be said that the natural one is the one that is more hit or miss.

And, as a wild guess, I would say that most people only know what farm-raised fish tastes like. In Japan, about 60% of Japanese amberjack (Buri), 80% of Red seabream (Tai), and 99% of Japanese eel (Unagi) are farm-raised. In other words, most Japanese likely eat farmed fish for these three species. The situation is similar around the world. Farmed salmon surpassed the catch of wild salmon in 1996, and currently accounts for more than 70% of total production.

This is the prerequisite for the answer so far. We then look impartially at the facts alone to come up with an answer.

A photo of fish farm

It is not difficult for a person with common sense to compare farmed hamachi and wild buri and recognize them. However, for those who have only eaten Hamachi and usually find it tasty, it may take some time to come to feel that Buri is tasty because their brain has a sense that such food is tasty. Modern people who find foods with amino acids and artificial sweeteners tasty command their brains to tell them that they are not tasty without them. When we become accustomed to foods that mask the original taste, we lose sight of the original taste. This is the true nature of convenient food. Therefore, when a fair comparison of natural Buri and cultured Hamachi Sashimi is conducted, more than 80% of people say that cultured Hamachi tastes better.

Fish have different flavors and aromas depending on where they are caught, and once you understand this, you can narrow it down considerably to the place of origin. The factors are the marine environment in which they live and the type of food they have been raised on. Natural fish can choose the food they eat, and those raised on such food have their original flavor. Fish raised in aquaculture are fed a diet that suits their needs because the emphasis is on economics. Because farm-raised fish cannot eat the food they prefer, they can’t develop their original flavors.

Nowadays, farm-raised eels dominate the eel market, and there is not a mere shadow of the natural product to be seen. Whenever we eat wild-caught eel, we always feel that farm-raised eel does not have the smell of earth and mud from the fat condensed in the skin and meat like wild-caught eel. Whether you like this smell or not, it is the original flavor of the eel. As for the quality of fat, farm-raised eel is not so bad when it is hot, but when it cools down, it feels heavy. Compared with farm-raised eel, natural eel is fatty but gives the impression of being light and smooth, which is why it has been called a specialty.

The iodine value is a number that indicates the degree of saturation or unsaturation of fat and oil. The higher this number is, the higher the content of unsaturated fatty acids and the worse the aftertaste tends to be. For example, farm-raised eel has an iodine value of 150, while wild eel has an iodine value of about 80, and contains almost no unsaturated fatty acids. Unsaturated fatty acids are abundant in Pacific saury (Sanma), Japanese sardine (Iwashi), Mackerel (Saba), etc. In short, these fish and farm-raised fish that eat food made from highly unsaturated acids will all have highly unsaturated acidic constitutions and will have a bad aftertaste. Moreover, if the fat is too strong, the fish will not even develop the aroma of the individual fish. This is one aspect of farmed fish.

Red seabream (Tai) is also available in both wild and cultured forms, but the amino acid composition and flavor compounds in both types do not vary much. Why, then, is there such a difference in taste? The only reason is the difference in flavor. The trace amount of aromatic substances in the fat of sea bream determines the original flavor of the fish. As mentioned above, farm-raised Red seabream does not have the same flavor. The question is whether the aroma is good for us or not. Of course, everyone has his or her taste in aroma. But that is where the value of the food is born. The top chefs are very particular about aroma, and they all use natural ones.

Finally, can you imagine what the results would be if you ate farmed Atlantic salmon and wild Atlantic salmon as sashimi? Probably, the farmed salmon would be superior because of its tender meat, appetizing color, and fat content (we could not find such experimental data, so this is speculation). However, what would be the result of making Nigiri sushi? The noble aroma that nature possesses is irreplaceable. In sushi, where the main focus is on enjoying the aroma, the difference is obvious.

The difference between natural and farmed fish is obvious, as the best sushi chefs never use farmed fish. The exception to this is when the fish is raised in an almost natural environment, without artificial food, so that it simply cannot escape.

All in all, the conclusion is that wild fish tastes better.

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What is hybrid artificial fish?

A photo of Kue-tama
The appearance of Kue-tama

What is hybrid fish?

Both Yamame (Landlocked Sakuramasu) and Japanese Iwana (Char) are members of the salmon family. Iwana and Yamame both inhabit the upper reaches of rivers, although Iwana prefers slightly cooler water. In rivers where each species lives alone, both fish occupy the upper reaches of the river, but in rivers where both species live, they do not mix, with Iwana occupying the uppermost reaches and Yamame occupying the lower reaches after a certain point in the upper reaches.

In nature, different species sometimes interbreed and produce hybrid fish. For example, hybrids between Yamame and Iwana are common in nature. The characteristic spots of the Iwana look like those of the Saba (Mackerel), a marine fish, and hence the name Kawasaba. They also rarely become smoltified (silvering) and become the descending sea type, but they do not reach sexual maturity.

Incidentally, the Kawasaba is thought to have been created by the uncontrolled release of Yamame into an area originally inhabited by Iwana, resulting in the mating of two species whose habitats do not originally overlap. The “hybrids” created by thoughtless releases may be a symbol of the destruction of genetic diversity.


What is hybrid artificial fish?

In the aquaculture industry, high growth and survival rates, good flesh quality, and disease resistance are important requirements for a superior species, and artificial crossbreeding has long been used as a method to create such breeds.

In 1964, Kinki University in Japan succeeded in breeding the first hybrid artificial fish, a female Red seabream (Madai) with a male Blackhead seabream (Kurodai). Since then, he has produced many hybrid combinations. The name “Ma-kurodai” is a combination of “Madai” and “Kurodai. In addition, he has created nearly 20 new fish species, including Madai x Hedai (Ma-hedai), Madai x Chidai (Ma-chidai), Ishidai x Ishigakidai (Kin-dai), and Buri x Hiramasa (Buri-hira).


Typical hybrid artificial fish will be mentioned briefly.

What is Buri-hira?

Buri hira is a crossbreed between a female Japanese amberjack (Buri) and a male Goldstriped amberjack (Hiramasa). Buri, which is in season in winter, is characterized by its high fat content and strong flavor, but its meat is tender and its dark red meat (chiai) tends to discolor during the summer. Hiramasa, on the other hand, is firm, has less dark red meat (chiai), and is less prone to discoloration, but has less fat and a lighter flavor, and is only available in summer.

Buri-hira is a very tasty fish that combines the “good points” of these two fish species and combines the “umami” of Buri with the ” chewiness and beauty” of Hiramasa. Because it is completely farm-raised, it can be served all year round, and major conveyor-belt sushi chains have already begun serving Buri-hira. Buri-hira can be caught in the wild very rarely, but they are so few that they are not generally available on the market.


What is Kue-tama?

It is a hybrid species, having as its father a Giant grouper (Tamakai), one of the world’s largest members of the grouper family that can grow to 270 cm in length and 400 kg in weight, and as its mother a Longtooth grouper (Kue), which is a rare and high-end fish with an outstanding taste and popularity.

The hybrid is characterized by the fact that it inherits the growth rate of Tamakai and grows to shipping size in about two years, whereas it normally takes four to five years for farmed Kue to grow to shipping size.

This makes it possible to significantly reduce production costs, and it also has properties that make it resistant to disease and easy to grow. Major conveyor-belt sushi chains have already begun offering Kue-tama.


What is Be-ster?

Be-ster is a hybrid of Beluga and Sterlet, known for producing the finest caviar among sturgeon. Developed by Russia several decades ago for aquaculture, the Be-ster was created amid a worldwide ban on capturing wild sturgeon as an endangered species.


What is Kin-dai?

Kin-dai is a hybrid of a female Barred knifejaw (Ishidai) and a male Spotted knifejaw (Ishigakidai) and was first successfully produced by Kinki University in 1969, and patented and trademarked in 1975.

Ishigakidai, on the other hand, takes more than six years to mature and produces fewer eggs, but grows quickly to commercial size. Kin-dai combines the best features of both, with a good texture and excellent taste. Its name is the same as the abbreviation for Kinki University.

Ishidai is called “Kuchiguro (kuchi means mouth and guro means black)” because its body turns silvery white and the area around its mouth turns black. Ishigakidai, on the other hand, is called “Kuchisiro (shiro means white)” because they have a black body and the area around their mouth turns white. Kin-dai’s entire body turns black, and the tip of its mouth also turns black.


What is Ma-chidai?

Kinki University has also produced a hybrid Ma-chidai, a cross between Red seabream (Madai), which grows well, and Crimson seabream Chidai, which has a less faded red coloration, and has traits that give it a red coloration like natural fish and faster growth than Chidai.

Finally, a second generation has already been produced from the sexes of the hybrid fish. If the hybrid fish are released into natural waters, contamination will occur through genetic infiltration. We should not leave a bad legacy for future generations.

What is Torokinme?

A photo of Fusenkinme.

Fusenkinme (Red bream) is occasionally caught along with Splendid alfonsino (Kinmedai). Until recently, they were considered to be the same species. Kinmedai has elongated slit-like posterior nostrils, while Fusenkinme has oval-shaped posterior nostrils. Kinmedai can grow over 50 cm long, whereas Fusenkinme stops at 40 cm.

Fusenkinme is fattier than Kinmedai and is called Aburakinme or Torokinme by fishermen, in areas that distinguish between Fusenkinme and Kinmedai, there is a difference in market price, but it is rarely distributed and is consumed locally.

Torokinme does not refer to the belly part of Kinmedai but to Fusenkinme, a rare species of Kinmedai. Incidentally, three Kinmedai, Nanyokinme, and Fusenkinme species are distributed in Japan.

Related contents:


What is the thought behind Toro?

What is Torokarei?

A photo of Torokarei fillet
The appearance of Torokarei fillet

Consumers are inevitably confused by the word Toro. It isn’t easy to separate the word from a mere marketing term. Therefore, the market contains fish names with Toro as a prefix.

Torokarei (karei means flounder) is a trade name for a fish named after the toro of tuna, which has a rich, tender texture, and is an arrowtooth halibut (Aburakarei).

Aburakarei is distributed north of Choshi, the northern Sea of Japan, the Sea of Okhotsk, and the western Bering Sea. Aburakarei is a typical eating fish among flounder species, and unfortunately, it is considered the most tasteless and has low commercial value. Black halibut (Karasugare), a relatively tasty and inexpensive fish, has become expensive, so perhaps it is Aburakarei’s turn.

So a name that would sell was needed, so it became Torokarei.

In recent years, Aburakarei has been imported from the U.S. and other countries in large quantities of fillets processed for frying. It is inexpensive and its distribution is stable. Aburakarei is characterized by its meat containing so much fat that it melts when heated. Even when heated, the flesh remains tender, and it is often used overseas for frying as fish and chips. The most common type of engawa at conveyor-belt sushi restaurants is either Aburagarei or Karasugarei.

Related contents:
What is the thought behind Toro?

What is Kudoa septempunctata?

A photo of Kudoa septempunctataKudoa septempunctata is a species of parasite (mucous sporozoite) of the genus Kudoa that parasitizes Bastard Hailbit (Hirame). It is approximately 10 µm in size and has a “hemispherical” shape when parasitized on fish.

Most cases of food poisoning due to cudweed are associated with fresh flatfish for raw consumption (e.g., flatfish sashimi). The infection rate and amount of infection are particularly high in farmed flatfish, which accounts for 60% of the food ingredients that cause kudoa food poisoning.

It is characterized by transient vomiting and diarrhea within a few hours after eating, with symptoms ending in a mild illness. Kudua has been shown to lose its virulence by freezing at -20°C for 4 hours or more, or by heating to a core temperature of 75°C for 5 minutes or more.

Therefore, food poisoning can be prevented by freezing it once and then eating or cooking it.

Related contents:

Studies on Seasonal Changes in Occurrence of Food-Borne Disease Associated with Kudoa septempunctata

We hope this information will be helpful.

Revision date: April 13, 2024

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Standing sushi bar in Tokyo that foreigners should definitely try!

a photo of Isami zushi
Isami zushi, which has a long history, is as inexpensive and delicious as Conveyor belt sushi, and has the atmosphere of a traditional sushi bar.

A quick cup of coffee and off to work I go. In this case, of course, you are standing rather than sitting on a chair. But when it comes to eating, sitting on a chair is the universal practice, isn’t it? In Japan, however, many restaurants allow customers to eat standing up, such as standing buckwheat noodles.

Why do these restaurants exist?

Certainly, a businessman who does not want to waste time will not allocate elegant time for a meal. In a sense, a businessman who wastes his time on such a wasteful activity may be a dropout. That said, how about eating a meal while standing up? According to Japanese eating etiquette, it is against manners to eat while standing. In many countries, it would be called ill-mannered.

And it is impossible to eat sushi, which has a strong image as a representative of high-class Japanese cuisine, standing up is not allowed. Nigiri sushi, however, was originally a yatai food (street food) for the impatient Edo people and could be called the fast food of the time. That and the fact that the customers were allowed to eat standing up and the seller sat down to make sushi, which is impossible today, but it was the norm back then.

Here, we would like to introduce Standing sushi bars in Tokyo that we would like foreigners to visit by imagining what yatai (street food) sushi was like about 200 years ago.

Standing sushi bars have been popping up in Tokyo since around 2021. It is impossible to rapidly increase the number of customers in a high-end sushi bar where the bill is several hundred dollars. Even if they opened a second sushi bar and entrusted the management to their apprentice, they would need to charge a certain amount of money to make it viable.

Therefore, the number of “standing sushi bars” should have increased to encourage people to come to the restaurant more casually. To be honest, while the business model was still in the exploratory stage, standing sushi bar Akira was selected as a Michelin Bib Gourmand in 2022. standing sushi bar is now in the limelight.

There are currently about 50 standing sushi bars in Tokyo, and among them, I would like to introduce Isami zushi, which has a long history, is as inexpensive and delicious as Conveyor belt sushi, and has the atmosphere of a traditional sushi bar.

Turn left from the east exit of Oimachi Station, turn left at the first corner, and enter the Higashikoji street that you will see immediately. Isami zushi will be on your left.

This area is a maze of narrow alleys and side streets with 60 to 70 bars and eateries that are reminiscent of the Showa period. Although not yet well known to foreigners, it is sure to attract attention as a town where one can feel the lifestyle of the people who live there.

Isami zushi has been in business for 67 years. The current owner, Masaaki Fujioka, is the third generation and has been running the restaurant for 25 years. The restaurant has an L-shaped counter and can accommodate seven people. At best, seven Japanese women can just barely fit inside. And if I may be rude, it feels even smaller than it is because of the lack of organization and placement of things.

The price per piece of nigiri sushi is 30 yen (Geso), 40 yen (Tamagoyaki), 60 yen (Ika), 80 yen (Tobiko), 100 yen (Aji, Aoyagi, Ebi, Saba, Akami, Hotate, Iwashi). , 120 yen (Tako, Kanpachi, Kohada, Hamachi), 140 yen (Torigai, Anago, Toro, Shako), 160 yen (Makimono), and up to 200 yen (Uni, Ikura).

You can order from two pieces. There are always about 20 different kinds of neta (toppings) available. Popular toppings are sometimes sold out, so it is best to get there early. Sushi rice is not too sweet and is suitable for eating sushi with a drink. Of course, sashimi is also available, so you can drink sake as well. The rice is a blend of Koshihikari and Sasanishiki, which gives the rice a delicious flavor and a flaky texture when you put it in your mouth.

How to Order

A sushi chef does not speak foreign languages. There is no English menu, so you must choose from a wooden tag with the name of the toppings written on it, or from a whiteboard with today’s recommendation. Or you can point to the fish in the glass case. Gari is not available at the counter like at conveyor-belt sushi restaurants, so please ask the sushi chef for “Gari-Kudasai” (Kudasai is a Japanese word meaning “please” in English). And regulars order three different sushi toppings at once. In any case, the hurdle may be quite high for foreigners. Even if your sushi order does not go as expected, it is inexpensive, there are no rip-offs, and it will be a memorable experience.

Why is it dramatically cheaper?

First, the restaurant is operated by a single sushi chef, which reduces labor costs. Second, he selects fish from the Toyosu and Ota markets, and fish arrives directly from Odawara, Nagasaki, and other areas. And because he strives to sell out the sushi topping every day. Also, he has reduced the size of his shari and sushi topping compared to previous years. These efforts are nearing their limits, so there may be a price increase soon.

How do I make a reservation?

Reservations are not available, so you will have to line up before the restaurant opens. The restaurant will be full as soon as it opens. Even if you say you will wait, you do not know what time it will be. Please be patient.

Payment Method

Credit cards are not accepted. Cash only. No table charges.

Actual Eating Report

We tried it and here is our report.

Well, we ate standing up, so we thought we could only hold out for about 30 minutes, but we didn’t mind quite a bit. Before our visit, we wanted to eat about 20 pieces as a goal. Japanese people consider someone’s feelings or wishes. In other words, if you are reporting on a sushi restaurant, you should write an article that will please the owner. I will say that this report does not have that element at all.

As soon as you enter the restaurant, a geta (sushi wooden tray) is placed in front of you and you are like, “Now what shall we nigiri? We think every sushi restaurant was like this 30 years ago. First, we ordered a beer. What a surprise, a can of beer was served. In Japanese restaurants, canned beer is rarely served. This is because cans can be drunk at home, and since the price is known, customers do not have a good feeling about it.

To start the conversation, we ask about the history of the restaurant. Then we confirm that it is okay to take pictures and will explore the most important sushi chef’s personality.

a photo of Black scraper (Umazurahagi), and Marbled rockfish (Kasago)
Black scraper (Umazurahagi) has a blurry appearance and does not look tasty, but once peeled, it reveals a clear white flesh similar to that of pufferfish.

Today’s shiromi was Hokke, Black scraper (Umazurahagi), and Marbled rockfish (Kasago). All of these sushi toppings are quite rare as shiromi. They are not served at high-end restaurants by mistake. Isami zushi uses natural fish from domestic fisheries for almost all of its topping. Because they do not use any farm-raised fish, the selection of toppings changes daily, but diners can enjoy rare local fish from all over Japan.

We ordered Umazurahagi and Kasago. The customer next to us also ordered Umazurahagi without a moment’s delay, but it was hard to miss the fact that he started making his order from ours. He does not make the nigiri sushi for the sake of efficiency. And of course, the fish is kept cold in a glass case with the skin on. This prevents oxidation of the ingredients as much as possible. And since the skin is the most delicious part of the fish, this is why we want to keep it on the meat until the very last minute. These are the basics of a sushi chef.

The liver is served on top of the Umazurahagi nigiri. Liver goes bad fast. It is meant to be alive and super fresh until a few hours ago. Its taste is often compared to that of foie gras, but it is not. Natural fish liver has a decidedly better aftertaste than foie gras. It makes you want to eat another piece. Kasago used to be a popular fish in the past, but now it is popular as a high-end fish. Sushi rice enhances the sweetness of the meat and gives it a different flavor from that of Red seabream (Tai) or Bastard halibut (Hirame).

A photo of Southern Bluefin tuna (Minami maguro)
Some sushi connoisseurs even prefer Southern Bluefin tuna (Minami maguro), as the lean meat lacks the slight acidity and faint aroma of blood that can be found in Pacific Bluefin tuna.

Next is the main dish, tuna. He insists on fresh, not frozen, tuna. He uses Mebachi and Minami-Maguro to keep the price reasonable. Today’s tuna was Minami-maguro. April to May is the time when the fat is removed from the meat of Kuro-maguro caught in coastal waters. Minami-maguro is next in rank to Kuro-maguro, but that is not true. Minami-Maguro is not widely distributed, so its richness is not well known. It also changes color quickly, which is its weak point.

Next is Geso, a specialty item at 30 yen per piece, Geso is squid’s leg. In fact, geso is not suitable for nigirizushi. The squid’s body is wrapped in a thin skin, and it is especially difficult to remove it from Geso. It is best for Tsumami when boiled or grilled. Fresh Geso, properly salted, has no fishy smell at all. The taste of the squid itself is concentrated. Try it with a dash of Nikiri shoyu.

Next is Aozakana (Blue-backed fish). These are caught in the morning and sent from the producing area. Today he has Horse mackerel (Aji) and Japanese sardine (Iwashi). The Aji is a top-quality fish from Amakusa, Kumamoto Prefecture, a famous fish producing area. The meat is thick and sweet when chewed. The ginger is used as a condiment to give it a refreshing taste. The Iwashi is in its peak of fatty season, and its light flavor was so delicate that one could hardly believe it was Iwashi.

Gizzard shad (Kohada) has larger pieces of sushi topping and smaller pieces of sushi rice. It is coated with a brush of Nikiri shoyu, so there is no need to dip it in soy sauce. The color is glossy and the fat is wonderful when eaten. And it is the type served at long-established sushi restaurants with the sourness of vinegar.

Shellfish available today are Ark shell (Akagai) and Common scallop (Hotate). Shellfish is a material in which it is easy to tell whether the quality is good or bad. If something tastes like chewing gum that has lost its flavor, it is not good. For Akagai, the key is whether or not the aroma of the sea pervades your mouth. Of course, the shells were removed after receiving the order. This way, the aroma of the sea does not escape. At first glance, the small-sized Hotate did not seem to have much sweetness, but I was impressed by its modest and elegant sweetness.

If we dare to make a bad comment after eating here, both the sushi topping and the sushi rice are 30% smaller than they were a few years ago. But that’s no surprise. They haven’t raised their prices even though prices have skyrocketed so high. In these days of conveyor-belt sushi, the toppings are as flimsy as paper.

Today we ate 18 pieces of nigiri sushi and 1 piece of Makimono in less than 1 hour. It is not painful at all to stay standing. Sushi is served on time, so you don’t have to wait around for it. And all this for only US$30. I think you can experience nigiri sushi to the fullest.

Basic Information

Address: 5-3-13 Higashioi, Shinagawa-ku, Tokyo

TEL: +81-3-3474-8089

: 1 minute walk from East Exit of JR Oimachi Station

Business hours: 18:00-23:00 (closes when all toppings are gone)

Closed: Saturdays, Sundays, and national holidays


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Revision date: March 19, 2024

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What is Kewpie mayonnaise?

An image of Kewpie mayonnaise
Since its launch in 1925, this mayonnaise has been the most popular mayonnaise in Japan!

Find out why Mayonnaise has become a citizen on the dinner table

Japan is not a large country. Even so, fresh produce from the sea and mountains is abundant. Even without a large-scale distribution system in place, we Japanese have been able to obtain fresh ingredients in fresh conditions easily.

This is thought to have given rise to a raw food culture in which vegetables, eggs, fish, and even internal organs such as horse meat, beef, and liver are eaten raw. Since fresh ingredients are readily available, it is only natural that there is no need to make unnecessary modifications to them. For this reason, Japanese cuisine has become dominated by methods that do not require much modification of the ingredients. In Italy, the ingredients are fresh, and in China and France, cooking techniques have developed to compensate for the lack of freshness of ingredients. This is just my personal opinion.

And speaking of Japan’s unique food culture, we must not forget its rice culture. Japanese rice is japonica rice, which is light and delicate in flavor. Inevitably, the rice is not eaten by itself but is accompanied by a strong-flavored side dish.

This is likely what led to the development of flavorful seasonings in Japan. The traditional Japanese soy sauce and miso, not to mention ketchup and Worcestershire sauce, which are two of the most popular sauces in Western cuisine, along with mayonnaise, are seasonings with a very distinct flavor. Likewise, mayonnaise is a strong-flavored seasoning, so it is assumed that side dishes made with it went well with rice.

In general, the Japanese palate is said to be well suited to amino acids and the peptide umami before it becomes an amino acid, and this amino acid is found mainly in fermented foods. Japan’s mild and humid climate is ideal for the production of fermented seasonings, and it is no wonder that miso (fermented soybean paste), soy sauce, and salted fish, which are fermented foods, have developed.

Interestingly, mayonnaise also begins to mature about a week after it is made, and the protein contained in the egg yolk in mayonnaise is broken down into amino acids and peptides, resulting in the umami that the Japanese like. Mayonnaise is usually not pasteurized because it separates when heated. This phenomenon occurs because the mayonnaise is still alive after being packed in the container.

Compared to the Western type of mayonnaise, which uses whole eggs, the yolk type of mayonnaise is more common in Japan. The yolk has a higher umami of amino acids and peptides than the egg white, and this may be the reason why Japanese mayonnaise has adapted well to Japanese tastes. The combination of this taste backbone and the umami of Japanese-style mayonnaise has helped mayonnaise to firmly establish itself in Japanese food culture.


What kind of food is mayonnaise?

I said mayonnaise is a food, but many people may think of it as a condiment. Mayonnaise, as you know, is made from vinegar, oil, and eggs. In Europe, where it originated, it was made from lemon juice, wine vinegar, olive oil, and eggs. However, in modern Europe, mayonnaise seems to be made at home, unlike in the United States or Japan.

Mayonnaise has some notable characteristics. First, the oil in mayonnaise has the effect of masking the bitterness of the food. Furthermore, the oiliness of mayonnaise is reduced by emulsification, making it very easy to eat. The bitterness of vegetables is sometimes unacceptable, but mayonnaise envelops it. Meat marinated in mayonnaise becomes tender. It has the effect of softening the hardened tissues of meat. Mayonnaise quickly removes the odor of raw fish. The sour vinegar flavor overcomes the unpleasant smell of raw fish, and when it is eliminated, it has so many positive aspects that there is no end to it.

Japanese mayonnaise is restricted by JAS standards for consumer safety. Incidentally, JAS is based on the standards of the U.S. FDA. According to the standard, mayonnaise contains 65% or more edible vegetable oil, vinegar and citrus juice, egg yolk and egg white, salt, sugar, spices, chemical seasonings, acidifiers, and citric acid. In Japan, mayonnaise may not contain any preservatives, emulsion stabilizers, food coloring, or soy protein. Yellow mayonnaise is just made with lots of eggs. This is why the JAS standard does not allow the use of food coloring that misleads people into thinking that there are lots of eggs in the product.


Why doesn’t commercial mayonnaise go bad?

Japanese standards for mayonnaise prohibit the use of any preservatives or food coloring. It is natural to ask the question, then, why mayonnaise does not spoil when it is made from egg yolks.

Simply put, think of pickles pickled in vinegar. Depending on the method of production, they can be stored for a year or more. The reason for this is that the acetic acid in vinegar has powerful bactericidal properties.

According to mayonnaise standards, at least 65% of the edible vegetable oil does not go rancid. The sterilizing power depends on how much acetic acid and salt are present in the remaining 35% of the ingredients.

Homemade mayonnaise made at home or in a restaurant is used up quickly, so there is no need to think about shelf life, just make it to your own taste. However, this is not the case with store-bought mayonnaise. And since mayonnaise is not heat sterilized, its composition is very important to prevent it from spoiling in its raw state. Of course, it is also important to manufacture it hygienically in a factory. The combination is determined by considering factors such as the fact that it must not separate during transportation and that it must have a taste preferred by the consumer.

According to actual bacterial test data, Escherichia coli is killed in 6 hours in mayonnaise. Staphylococcus and salmonella, which cause food poisoning, are killed in 24 hours. Even the yeast Hansenula anomala, which is relatively acid-resistant, dies in about 8 days.

As a general guideline, raw food is considered hygienic if it contains less than 100,000 live bacteria per gram. Frozen food that is heated and eaten meets the criteria of the Food Sanitation Law with a count of 3 million live bacteria or less per gram. Normally, it is considered that even if there are 100,000 bacteria per gram of food, the food will not spoil, but if the bacteria count exceeds that level, the food will gradually start to spoil or go rancid. In other words, most bacteria die in mayonnaise. Therefore, it is safe to assume that commercial mayonnaise is first of all free of bacteria.


Why is vinegar good for your health?

The answer is simple. It is because vinegar lubricates the citric acid cycle. In 1953, Dr. Hans Krebs of England won the Nobel Prize in Physiology or Medicine for his research on the pathway of tissue respiration in the human body. This is called the citric acid cycle, which is the only mechanism that produces the energy necessary for life, and without this cycle, organisms cannot live!

The problem here is that during strenuous exercise or illness, large amounts of glucose are burned, creating an abnormally high amount of pyruvate, which is further converted into lactic acid. That lactic acid makes body fluids and blood acidic, causing so-called Acidosis. In addition, lactic acid combines with proteins in body tissues to form lactic acid protein, which causes stiff shoulders and muscle pain, as well as increased deposition of cholesterol, leading to arteriosclerosis and hypertension.

At this time, it is explained that when vinegar is eaten with salads, the organic acids contained in vinegar, such as acetic acid, malic acid, and citric acid, can smoothly advance the citric acid cycle and bring lactic acid back into the cycle. In other words, vinegar has been elucidated to act as a lubricant for the Citric acid cycle.

The vinegar in mayonnaise does more than just accentuate the delicious taste; it also helps to clear away fatigue. The Citric acid cycle explains why the blood and body fluids of healthy people are slightly alkaline and become acidic when tired or ill. It also depends on the diet. Eating only acidic foods, i.e., meat and seafood, will cause the blood and body fluids to become more acidic, and cholesterol will be deposited in the blood vessels more easily. The diet must be well-balanced. This is where vinegar comes into play. Vinegar is burned efficiently in the body and is incorporated into the metabolic mechanism to act as an alkaline food. Other effects include increasing appetite and aiding digestion, and it is also very effective in cleaning the body and activating the body’s internal energy.

Where does mayonnaise’s good taste come from?

Mayonnaise is an oil-rich food. Oil stimulates the brain to release hormones that make us want to eat again. However, oil does not remain in its original state, but is scattered throughout the food, creating a richness. Humans respond to this richness with a sense of deliciousness. In other words, mayonnaise is a synergy between the richness created by the oil mixed and dispersed in the egg and the richness of the egg yolk itself.

What makes mayonnaise different from other seasonings is that it contains the egg itself, rather than food extracts or essences. We believe that mayonnaise itself may be regarded as an independent food or dish, beyond the framework of a mere sauce.

Isn’t too much mayonnaise bad for you?

One of the main components of mayonnaise is egg, a food high in cholesterol. However, since mayonnaise is a food high in cholesterol, it is too early to assume that it is bad for you.

The main functions of cholesterol include “making cell membranes,” “making bile acids,” and “being a raw material for sex hormones and adrenal corticosteroids. The production of cell membranes is the basic building block of the human body, without which the human body would not exist. Bile acids are necessary for digestion, and without normal amounts of bile acids in the body, digestion would be out of balance. The same is true for hormones. Without a certain amount of cholesterol in the body, the human body cannot function normally.

The term “cholesterol” refers to both HDL cholesterol and HDL cholesterol. HDL cholesterol is necessary for the body, and most of the cholesterol contained in egg yolks is HDL cholesterol. On the other hand, LDL cholesterol, which is said to cause arteriosclerosis, is not in itself bad. It is believed that oxidized LDL cholesterol, which is created when LDL cholesterol is oxidized by active oxygen, damages the vascular wall, causing inflammation and arteriosclerosis.

Cholesterol is not only ingested through diet. About 70% of the cholesterol needed by the body is synthesized in the body, and the remaining 30% is taken in by the diet. Incidentally, the amount of cholesterol synthesized by the body is 600~700mg per day. On the other hand, a 50 g egg contains about 235 mg of cholesterol. The proportion of egg in Mayonnaise is lower than it appears, and the amount of cholesterol contained in a tablespoon (15g) is only 24mg. This is not an amount to be concerned about.

The human body is well designed to maintain balance by reducing the amount of cholesterol synthesized in the body when the amount of cholesterol in the diet is too high. In addition, cholesterol is transported from the liver to each tissue, and conversely, cholesterol is collected from each tissue to the liver, thereby keeping the amount of cholesterol in the blood at a constant level. The problem is not the intake of cholesterol itself, but the imbalance of cholesterol in the blood.

And an experiment has been conducted with surprising results. Healthy subjects and hyperlipidemic subjects were given 15 g of Kewpie mayonnaise per day for 12 weeks in addition to their conventional diet, and the lipid levels in their blood were measured. The total cholesterol concentration in the blood of the healthy subjects was slightly decreased. The hyperlipidemic subjects also showed a decreasing trend. It would seem that a constant intake of mayonnaise would increase the amount of cholesterol, but in the experiment, there was no trend toward an increase. In addition, there was no change in body weight after 12 weeks of mayonnaise consumption, a result that defies the conventional wisdom about mayonnaise. Similar experiments have been conducted elsewhere with the same results.

New Possibilities for Eggs

The amount of choline needed per day is said to be around 450 mg. 1 egg weighing 60~70 g contains 1000 mg of choline. 1 tablespoon of 15 g of mayonnaise contains about 110 mg of choline, which is 1/4 of the daily requirement. One-quarter of the daily requirement of choline can be obtained from a 15 g spoonful of mayonnaise. Incidentally, 200 cc of milk contains 28 mg, and a tablespoon of butter contains 20.4 mg, so eggs are by far the most efficient way to eat.

Mayonnaise contains a lot of salt

Mayonnaise is a sour and salty food, and while one may worry about too much salt if one eats too much, it is much less salty than one would generally imagine. The saltiness is due to the seasonings and spices. It contains less salt than other seasonings. Mayonnaise has 0.3 g of salt per tablespoon, the lowest amount of salt among the major seasonings, compared to 0.6 g of ketchup, 3 mg of soy sauce, and 2 mg of miso. Despite its low salt content, the full-bodied mayonnaise can add a lot of flavors to ingredients even in small amounts, and may be considered a good choice for dieting.

Does eating mayonnaise make me fat?

Usually, a tablespoon of mayonnaise has 100 kcal. One hot dog has about 289 kcal, so three tablespoons would be the same calories. It is certainly a high-calorie food. It is a very oily food, but the vinegar makes it surprisingly refreshing, which is one of the reasons why we tend to eat a lot of it. We should not eat too much of this food just because it tastes good but try to eat about 1 tablespoon per meal. It is not harmful to your body even if you continue to eat it every day, but only if you know how much to eat. It is not recommended to eat so much that you can’t see the salad. Instead of worrying about gaining weight, one should try to eat a well-balanced diet by eating green and yellow vegetables together.

Pairing mayonnaise with other foods

The range of uses for mayonnaise is unlimited. Please listen to this article without preconceived notions that mayonnaise would not be suitable for such foods. First of all, in the case of Japanese food, it is difficult to find foods that mayonnaise does not go well with, such as broiled eel, tempura, yakitori, oden, chilled tofu, soba noodles, and so on. Other than that, it goes well with all kinds of food such as gyoza, ramen, shumai, spring rolls, bibimbap, kimchi, tom yang kung, beef stew, omelets, curry rice, minestrone, edamame, banana, apple, orange, apple pie, pudding, chocolate, donuts, and many others. It can soften the aroma of stinky foods, freshen oily foods with its acidity, and deepen the flavor of overly light foods with the richness of eggs.

The emergence of polyethylene multi-layered containers

When Mayonnaise was launched in Japan, it was in glass bottles. In the 1960s, plastic was developed, polyethylene containers appeared, and bottling containers were quickly converted to polyethylene containers. Glass bottles were used because oxygen permeation would oxidize the mayonnaise oil and form peroxides, which would gradually ruin the flavor. However, the ability to squeeze out without using a spoon seems to have been significant, and it seems to have been replaced.

The difference in preservation effect on mayonnaise between polyethylene containers and glass bottles was that polyethylene alone had the disadvantage of poor preservation compared to bottling due to its oxygen permeability.

In the 1970s, technological advances made it possible to improve the oxygen permeability of polyethylene. A three-layer technology was developed, with polyethylene on both sides and an oxygen-impermeable plastic-like eval resin in between.

The three-layer polyethylene-eval resin-polyethylene container is used today for most food containers. This has greatly improved the shelf life of mayonnaise and has made bottled and polyethylene multi-layer containers nearly identical in terms of quality.

Bottled mayonnaise is more prone to oxidation after opening because of the large area exposed to air when the lid is opened. Polyethylene multi-layer containers have become the mainstream in Japan because of their advantages such as easy squeezability, no risk of breakage, lightweight, and low container cost.


Here is a summary of the characteristics of Kewpie mayonnaise.

The main ingredients of Kewpie mayonnaise are also oil, eggs, and vinegar. Of course, each of these ingredients should be carefully selected and good ones used, but the strange thing about mayonnaise is that it does not taste perfectly delicious on its own.

What became clear in Kewpie’s laboratory is that what is important is the compatibility of vinegar and oil, and vinegar is a major key, especially in terms of umami. Surprisingly, vinegar and oil go together better when they are both strong. If one of the habits is weak, the other will win out and instantly become unbalanced.

Let’s look at the history of the oil used in Kewpie mayonnaise. In the postwar period when mayonnaise became popular, cottonseed oil from cotton seeds was mainly used. Since this oil has a strong habit, it was combined with malt vinegar, apple cider vinegar, and other vinegar with strong characteristics. However, with the development of synthetic fibers in the 1960s, cotton cultivation decreased and cottonseed became scarce. This made it difficult to secure cottonseed oil, and other oils with weaker characteristics were used instead. Kewpie has changed the vinegar to match the oil.

These days, Kewpie uses a blend of vinegar made from sake lees and grains. The ingredients of oil that are good for the body are generally considered to be oleic acid, linoleic acid, and α-linolenic acid in the ratio of 60:32:8. Rapeseed oil, for example, is close to this ratio, and Kewpie uses salad oil that is also close to this ratio.

Although oil accounts for the largest proportion of ingredients, vinegar can be said to be the key to flavor. Taste preferences are said to change over time; for example, Kewpie mayonnaise was sourer in the past. The percentage of vinegar is said to be less now than in the past. In the past, there were few homes with air conditioning, and people sweated a lot. Therefore, mayonnaise with a lot of vinegar and a strong flavor was preferred. On the other hand, today, air conditioning is available everywhere, and people do not sweat as much, so the amount of vinegar is less than in the past.

Compared to mayonnaise made overseas, Japanese mayonnaise generally contains almost double the amount of vinegar. This is because mayonnaise is a unique egg yolk type of mayonnaise in Japan, and cannot be heat sterilized like other foods because it decomposes when heated. In addition, mayonnaise with high yolk content is prone to spoilage, and to prevent this, a lot of vinegar, a natural preservative, was used. This ultimately made Kewpie mayonnaise tastier.

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Revision date: March 15, 2024

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What is sushi or sashimi grade fish?

sushi or sashimi grade fish photo
Do you know when this fish was caught?

Fish is not only cooked and eaten as grilled or boiled fish but also eaten raw as sushi or sashimi. Naturally, the way to eat fish depends on individual tastes. But in fact, the way we eat fish depends on the time frame after we catch it.

Fish that is still alive or freshly dead is ideal for sashimi. In this case, you should enjoy the elasticity of the flesh, or texture, rather than the umami of the fish. Only the freshest fish is suitable for sashimi. The fish will go rigor mortis within a few hours at the earliest, and within a few days at the latest. The period leading up to rigor mortis is the time when the umami component increases, making it ideal for sushi.

On the other hand, the flesh becomes softer, so it is the sushi chef’s job to find the right balance between the umami and the chewiness of the fish. Of course, for those who prefer fish with more umami, it can also be served as sashimi. The rigor mortis of the fish is eventually dissipated and it gradually begins to decompose, so it is consumed as sashimi or sushi until a certain point in time.

The chef’s job is to determine when the fish cannot be used as sashimi or sushi. After that, the fish will be consumed as grilled or boiled fish. Eventually, the color, taste, and aroma of the fish will change dramatically, and it will reach the so-called putrefied state, making it inedible. The chef’s job is to determine when the fish cannot be used as sashimi or sushi. After that, the fish will be consumed as grilled or boiled fish. Then the color, taste, and aroma change dramatically, and the fish reaches the so-called putrefied state and becomes inedible.

A variety of conditions exist before rigor mortis sets in. Ideally, the fish should be properly processed and cooled as soon as possible after it is caught. Without this, rigor mortis will set in immediately, shortening the time until the rigor mortis is dissipated and speeding up the decomposition process. In other words, it will affect the length of time the fish can be enjoyed.

It is difficult to judge whether fish can only be used for grilled or boiled fish. It is not a simple matter of how many hours after the fish has died. Even if the fish is in sushi or sashimi grade, you can imagine that some are in good condition, and others can only be used almost exclusively for grilling or boiling.

Look around the world and you will see fish being sold around fishing ports as soon as they return from fishing. The fish is truly freshly caught and could not be fresher. Usually, the fish is cooked by dinner at the latest, so the loss of freshness is not a concern at all. People call fish in this state very fresh. To be more precise, it takes a few hours from the time the fisherman catches the fish to the time it is on the market, or at most 12 hours before it is served for dinner. This is what we call sushi or sashimi grade. However, because the fish is not caught in large quantities, it is not distributed to supermarkets in urban areas. This is limited to fishing with small boats.

Large vessels use large nets and other equipment to catch large numbers of fish. When the nets are raised on deck, many of the fish are live. They are quickly sorted, cooled with ice or other means, and placed in refrigerated or frozen storage. Some of the larger fish are stored after Ikejime, etc. Once fishermen go out to fish, they are not allowed to return for at least three days and as long as several months.

Although refrigeration and freezing technology have advanced considerably, freshness is not the same when the fish is caught as it is when it returns to the fishing port. And by the time the fish reaches the supermarket, which is a long way from the fishing port, it is arguably even less fresh. It has already been almost 24 hours since the fishermen caught the fish. It will then spend several days in the supermarket enduring temperature changes and drying out. One wonders if this can be called sushi or sashimi-grade fish.

So far, we think you can understand that this is a typical situation in countries other than Japan.

The situation in Japan is a bit different.

Regardless of the size of the boat, the fish are not allowed to get out of control, Ikejime and other processing is done. And cooling is always done. That is what even the average fisherman does as a matter of course. In other words, it is recognized that keeping fish fresh means delaying the time until rigor mortis.

On top of that, a distribution system has been established to deliver the caught fish to markets and restaurants while keeping them alive. Not only are the fish kept alive, but the know-how to reduce stress during fishing and transportation is shared among fishermen. For example, fish are transported by truck to the consumption area in a state of suspended animation to prevent them from getting out of control. In other cases, fish are not shipped immediately from the fishing port, but are allowed to calm down in a fish tank. By trying to keep the fish as close as possible to the state in which they were swimming in the sea, the fish can recover their original amount of adenosine triphosphate. This is because adenosine triphosphate is the source of umami, which eventually converts to inosinic acid.

In other words, a system is in place to distribute fresher and tastier fish. As a matter of course, it is safe to say that the fish is delivered from the fishing port to the place of consumption and then displayed in supermarkets within 12 hours.

The minimum requirement is that the fish must be usable for sashimi. The words sushi or sashimi grade do not exist in the market. Who caught the fish? What time and minute it was caught? How was it processed? Whether the fish was caught by fishing or by netting, and other details are required. These things change the price of the fish in the market.

In summary, there is no legal definition of sushi or sashimi-grade fish. When seafood is labeled as sashimi grade, it means that the seller, such as a supermarket, has determined that the fish is suitable for sushi or sashimi, based on its evaluation of criteria such as bacteria levels, temperature, parasites, appearance, odor, taste, display method, and time since catch. It is very vague and does not state that they are responsible for any problems that may occur, such as food poisoning. In the extreme, it is merely a marketing term for sales promotion purposes. Above all, they say nothing about actual quality or taste.

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Revision date: March 1, 2024

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What does texture have to do with the taste of sushi?!

Texture is a tactile sensation that is felt when food is physically stimulated in the mouth. Tactile sensations are felt by pressure receptors in the skin, tongue, and periodontal ligament of the mouth that are deformed.

The role of the pressure receptors in the mouth is to obtain information to determine if food can be digested and nourished. Digestion is made possible by physically destroying the food, making it smaller, and breaking it down with enzymes. Only when the molecules are small enough can they be absorbed by the small intestine and other organs. Chewing in the mouth is the first step in this process. In the process of chewing, the food becomes smaller and smaller, and the texture changes rapidly.

The Japanese are the ethnic group with the most textural language. According to a survey on the number of terms related to texture, Japanese has about 500 words related to texture. In contrast, Chinese has about 150 words, French about 250, and German and English about 100. The Japanese have created a wide variety of foods with different textures by distinguishing and enjoying the differences among these many words used to describe textures.

Texture and taste are not directly related, since they are sensed by different receptors and are carried as information to the brain by different nerves, but the release of taste substances from hard foods is slower, and thus taste is perceived more slowly. On the other hand, the opposite is true for soft food, which tastes more quickly.

Nigiri sushi is made with an emphasis on texture. The act of aging sushi topping is waiting for the texture to soften in terms of physical changes. The purpose of this is for the sushi topping to adhere to the sushi rice. In conjunction, it is waiting for the production of inosinic acid, an umami substance. Shrimp, squid, and other ingredients not only become softer but also change to a gooey state. In this way, there is an aspect that makes it easier to perceive the taste.

Several techniques are used to mix the sushi ingredients and sushi rice in the mouth. We make sure that one or the other does not move first from the mouth to the back of the throat. If the sushi rice remains in the mouth, it is equivalent to eating sashimi, and the synergistic effect of umami cannot be expected. The way to do this would be to slit the sushi topping as much as necessary. The sushi rice and the sushi topping become as if they are one food. Of course, this also serves to improve the texture by cutting off white streaks and small bones.

Even the same portion of the same sushi item can have different textures depending on the sensitivity of the sushi chef. In other words, the taste changes. It is as if one were to choose a 500-word term for the texture, and then cast a spell on the sushi item. It is fun to guess what the sushi chef wanted to express.

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Revision date: February 26, 2024

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