
We hope this information will be helpful.
Revision date: July 18, 2019

We hope this information will be helpful.
Revision date: July 18, 2019

We hope this information will be helpful.
Revision date: June 11, 2019

We hope this information will be helpful.
Revision date: June 4, 2019

We hope this information will be helpful.
Revision date: April 22, 2019

We hope this information will be helpful.
Revision date: April 16, 2019

Chilean fish farmers are using large quantities of antibiotics to control fish diseases. They use 500-700 times more antibiotics than Norway does. 80% of antibiotics imported into Chile are intended for the fish farming industry. Faced with the risk of bacteria resistant to antibiotics emerging, as highlighted by the World Health Organization (WHO), the Chilean National Fish Service is calling for a reduction in the use of antibiotics. (Extract from Le Monde diplomatique Japanese edition)
The bright color of salmon is something that you would never see a long time ago, but is now commonplace. It is likely due to the Canthaxanthin pigment mixed into their feed. Salmon is in fact a white fish. The salmon that is caught in Japan is called “Shirozake” or white salmon and its flesh is not a pink before it goes out to sea. Once it is out at sea, it swims around consuming small plankton and crustaceans such as shrimp and krill. Its body then takes on a pink color due to the intake of natural coloring of Astaxanthin. This Astaxanthin has antioxidant effects and it is noted for playing a part in relieving fatigue and preventing aging. However, the synthetic pigmentation that creates the salmon pink does not provide the same health benefits.
The US Food and Drug Administration (FDA) gave approval for genetically modified salmon on November 19th, 2015. This genetically modified salmon is called “AquAdvantage salmon.” It grows faster than regular salmon and its body length is almost double. There are groups opposing the sale of this salmon, including US citizen group Center for Food Safety, the Japanese Seikatsu Club, and the European parliament. There are still many unknowns regarding the safety of this type of fish for human consumption, and a number of issues are still being debated. The discussion has been featured in “Nature” magazine.
Endosulfan is a type of organochlorine compound, like Dichloro Diphenyl Trichloroethane, Dicofol, Heptachlor, Chlordane, Mirex, Pentachlorophenol, and is known to be extremely toxic, but the EU approved Endosulfan for use as feed in Norway’s salmon farming industry in 2013.
Researchers analyzed the risk-benefit ratio based on levels of contaminants like dioxins, PCBs and chlorinated pesticides versus omega-3 fatty acid levels. While farmed salmon is higher in omega-3s, it is also significantly higher in these toxins (about 10 times) which can produce birth defects, lower IQ, and cause cancer. They determined the following based on origin of the salmon: “consumers should not eat farmed fish from Scotland, Norway and eastern Canada more than three times a year; farmed fish from Maine, western Canada and Washington state no more than three to six times a year; and farmed fish from Chile no more than about six times a year. Wild chum salmon can be consumed safely as often as once a week, pink salmon, Sockeye and Coho about twice a month and Chinook just under once a month.” (Extract from The Journal of Nutrition)
On the other side of the debate, there are articles such as the following. Norway’s NIFES (National Institute of Nutrition and Seafood Research) sampled 13,180 farmed fish (of which 90% were salmon) and monitored them for medicines, substances that are prohibited by law, and other pollutants, publishing their report on August 17th 2015. In their latest report, it concluded that Norwegian farmed fish were safe and that illegal and undesirable substances were not observed to exceed standards. Further, it seems that they have confirmed decrease in most of the pollutants analyzed in the investigation.
But the fact is that, according to these articles, while the chemicals did not exceed standard values, they were certainly found to be present in farmed salmon. The other extreme would be to say that eating natural un-farmed salmon will not expose you to the potential risks from these types of chemicals.
However, that’s not really practical. The global production of farmed salmon is 2.5 million tons a year, approximately three times the 800,000 tons of naturally fished salmon. No matter what way you slice it, the option of farmed salmon isn’t going away anytime soon.
The Right Kind of Fishy: Can I Eat Raw Salmon?
We hope this information will be helpful.
Revision date: October 22, 2021
In the United States, Sea Bream is often called a Red Snapper. However, strictly speaking, this is not correct.

So, what is the fish that Japanese sushi restaurants call “tai”?

Incidentally, relatives of the sea bream often served at sushi restaurants include red sea bream (madai), crimson sea bream (chidai) and yellowback sea bream (kidai). While “kinmedai” (Splendid alfonsino) and “amadai” (horsehead tilefish) have the name “tai/dai” in them, they are not part of the same family as “tai”. Splendid alfonsino is a type of deep-sea fish.
Red sea bream and red snapper look similar, but when served as sushi, their texture and flavors are entirely different. So if you come to Japan, please try and eat natural madai. There is no “zatsumi” (overpowering bitterness) and it has a slight sweetness to it. This is the taste of tai, known as the king of the white fish. Just for your own reference.
Related Contents
https://sushiuniversity.jp/visual-dictionary/?Name=Red-seabream-(Tai)
We hope this information will be helpful.
Revision date: April 28, 2020

*It is said that nigiri-sushi in the Edo period was bigger than it is today, and too big to eat in one bite. In the Meiji period, the custom emerged of splitting this one big portion into two to make more easily consumed portions, and this is why it is common to get sushi in sets of two. However, nowadays making one piece of nigiri-sushi at a time is not very efficient. We think it’s actually easier for the sushi restaurant to make them in sets of two. Of course, you can order them one by one.
But the sushi restaurant won’t count them like that. Formally, sushi is counted in this way: Ikkan (one), Nikan (two).
We have absolutely no idea where the custom of using the “kan” counter came from. It’s also not clear when use of that counter for sushi started.
Of course, there are theories. For example, there is a theory that back at a time when a single unit of money was called “kan.” The price for one piece of sushi was around 1 ‘kan’, and the counting method gained popularity. There is another theory that one sushi roll was counted with the counter for roll “巻” (also pronounced “kan”), then a different kanji was used for it later. However, these are just theories that were created after the fact and the mystery remains unsolved.
Even if you ask the owner of a sushi restaurant, they’ll probably cock their head to one side, think for a moment, and tell you that the “kan” mystery may never be solved.
Sushi rolls wrapped in seaweed rolls are counted in units of 本 (hon/bon/pon) in the wrapped state, and when cut with a knife, the units change to 切れ (kire). While these units are fairly straight-forward for Japanese language speakers and easy to understand, only the enigmatic 貫 (kan) remains a mystery.
We hope this information will be helpful.
Revision date: April 29, 2020
The original negitoro is made from medium fatty tuna or nakaochi* chopped up finely with a knife and then mixed with chopped green onions on top. But the tuna may be switched out with filler, leading to a variety in quality of the negitoro available.

The medium quality uses the nakaochi of cheap Albacore tuna or Swordfish.

Finally, let me introduce some negitoro trivia. There is a lot of flesh on the middle bone (spine) and the surrounding area for tuna and the like. This is called “nakaochi*”. Scraping the meat from this area surrounding the spine is known as “negitoru”, which is where the word “negitoro” comes from. In other words, the name “negitoro” is not actually from the words onion (negi) and tuna belly (toro).
What is negitoro like at Sushi restaurants?
Originally, the meat from the middle cut or in between the bones of the tuna was used for negitoro. In order to get meat from these parts, the chef would have to purchase an entire tuna, or buy the cut that includes the mid-ribs. However, both of these purchases are difficult for a single sushi restaurant, so now the chef chops the meat from the body with a butcher knife until it forms a paste that is sticky and smooth from the fat in the tuna. This paste is used for negitoro.
We hope this information will be helpful.
Revision date: July 21, 2020
Kakushiaji refers to a technique where a single seasoning (For example, sugar, vinegar, soy sauce, salt, etc.) is added to a dish. The Kakushiaji contrasts with the finished dish’s flavor, and is added in an amount too small to notice when served. This produces a clear improvement in flavor.
Examples include adding a little salt to heighten sweetness, or adding a little vinegar to a simmered dish. Sometimes these combination of flavors can be quite surprising, like adding a touch of chocolate to a curry.
We hope this information will be helpful.
Revision date: November 7, 2018
Umami describes the delicious taste of savory flavor essences. For many years, people held to the belief that humans can taste only four basic flavors (sweet, sour, salty, bitter) unitil a japanese chemist named Kikunae Ikeda discovered a fifth flavor (glutamic acid) in the early 20th century.
The main umami ingredients are glutamic acid in seaweed, inosinic acid in dried bonito and meats, succinic acid in shellfish, guanylic acid in shiitake mushroom.
Many ingredients contain a wide variety of umami essences. In combination, they create a synergistic effect which produces an even more potent savory flavor.
We hope this information will be helpful.
Revision date: October 31, 2018
The ginger served in sushi restaurants is called “gari”. There are people who just chomp down the gari since it’s all free.


When made at these factories, large amounts of ginger is soaked in the stock solution, creating gari in bulk. The quality has improved greatly over the years, but often the fibers are crushed making it soggy, or the gari is stained from ume vinegar.
On the other hand, homemade gari and gari made in Japan is flavored with vinegar and salt while sugar is used sparingly as a subtle flavoring. Handmade gari is crunchy and chewy. The color is also the original pale yellow of ginger.
And during the fresh ginger season at the beginning of summer the price of fresh, domestic ginger jumps up to thousands of yen per kilogram. Since ginger has a high water content, it can be wrung out to reduce 1kg of ginger down to 300g. Making delicious gari by hand costs money. It is also a daunting task of making a year’s worth in advance. Once it’s done there has to be a refrigerator dedicated to storing only the gari.
When you put it that way, homemade gari is far more expensive than its imported equivalent. Providing homemade gari is one of the things that sets sushi restaurants apart from each other. Of course even if you’re not charged for the gari, eating too much will affect your sense of taste for the meal.
We hope this information will be helpful.
Revision date: October 8, 2018
As far as I know, there are three ways “sushi” is written on sushi restaurant curtains in Japanese kanji characters: 鮨, 鮓 and 寿司.
Do you know the difference? Most Japanese people don’t know the answer to this question.
Broadly, in the Kanto area 鮨 is generally used while 鮓 is more common in Kansai. 寿司 is used commonly everywhere in Japan.
However, of the three, only 鮨 and 鮓 are seen in ancient Chinese literature. 鮨 was seen as a dictionary entry as early as the 5th to 3rd centuries B.C., and it’s origin is described as combining “fish” and “shiokara” (briny flavor) resulting in the term 鮨.
On the other hand, in A.D. 1st to 2nd century dictionaries, “鮓” appeared, and is explained to depict “a storage container for fish.” Toward the end of the second century 鮓 was used for the term “narezushi”.
But around the third century, the briny meaning of 鮨 and the term “narezushi*” written as 鮓 started to be used interchangeably. That is how the words were imported to Japan.
In Japan, the character “鮓” was often used in literature from the end of the Heian era to the end of the Edo era. Eventually the use of “鮨” was revived during the Meiji era (for unknown reasons). It was a natural transition that Kanto came to use “鮨” and Kansai came to use “鮓”.
Incidentally, the kanji “寿司” was created from the phonetics. Its use for celebratory occasions became commonplace throughout Japan.
*”Narezushi” is the primitive version of Japanese sushi. It means covering seafood with salt and then soaking in rice for a few years as a form of lactic acid fermentation, which brings out the acidity.
We hope this information will be helpful.
Revision date: April 29, 2020
One important task of sushi chefs is going to Tsukiji (Toyosu) every morning, looking at fish with their own eyes and assessing the quality. Having a good eye is important in order to get the highest quality possible, but this is cultivated by experience. They are also constantly obtaining information from the fishmongers at the market regarding what the best fish of the season and their localities. It’s almost a game as to whether they can get high-quality fish at the optimum price everyday. The skills of a sushi chef start with this assessment.
We hope this information will be helpful.
Revision date: September 11, 2018
Many regular patrons of sushi restaurants look forward to having casual conversations with the sushi chefs. It might be difficult to understand for visitors who don’t speak Japanese, but sushi restaurants are the only restaurants in the world that customers can speak directly with the head chef. If you don’t need conversation, then the waiter could just bring the sushi made back in the kitchen. Of course they also want customers to see the beautiful act of making sushi, but there is no particular reason that the sushi has to be made in front of the customer. The technical term for this is “Exposed Business,” meaning that the chefs are putting themselves on display for the customers. Did you learn something new?
We hope this information will be helpful.
Revision date: September 2, 2018