What is Karami?

Sashimi essentials such as wasabi, ginger, karami-daikon, etc., are collectively called “Karami”. Originally Karami was a type of Tsuma. From the mid to late Edo period, Karashi (mustard) was mainly used for karami in sashimi. Eventually, due to the influence of Edomae sushi, wasabi became the norm. For sashimi such as bonito and sardines, wasabi isn’t enough to offset the peculiar aroma. In some cases, it is better to use ginger, which works on the root components of the odor. These types of fish have the best flavor once spring has passed, and interestingly enough, wasabi is least prevalent in summertime, while ginger is in peak season. Mother nature seems to know what she’s doing.


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Revision date: April 5, 2021

What is the trick to super cheap Ikura at conveyor belt sushi restaurants?

Immature salmon eggs still wrapped in ovarian membrane and salted are called sujiko. Ikura is salmon roe in which each mature egg is separated from the ovarian membrane before laying the eggs and then salted or marinated in soy sauce. The ikura of Chum salmon going upstream in the Kushiro River and Tokachi River in Hokkaido From October to December are considered to be premium ikura.

For cheap ikura, roe broken up inside the ovarian membrane in a fish that is approaching spawning time called “barako” is used. When the ovarian membrane of barako is torn, the eggs will fall out and scatter, so while they don’t take much work to prepare for serving, they also don’t taste particularly good. Even cats turn up their noses at barako, so they are also called “neko-matagi”, which literally means “the cat walks over it” and is used to refer to unpalatable fish. However, each egg is large and they look very appealing, so they are used at higher-end conveyor belt sushi. Unlike the 100-yen (US $1) restaurants, these higher-end restaurants don’t use disguised fish or substitute fish. This is because their basic business strategy is to differentiate themselves by attracting customers with authentic toppings. Generally they market the high quality of their toppings, but the ikura is actually this cheap “neko-matagi”.

Beneath this strategy of attracting customers with authentic toppings is this “Deceptive business strategy”. Salmon also swims upstream in the rivers of Tohoku and Hokuriku. However, the taste of ikura tastes inferior to that in Hokkaido. This ikura is also served at the higher end restaurants. That’s because although it doesn’t taste as good, it’s orthodox ikura. In case of orthodox ikura, the roe is used within one hour of the catch. But, if time passes and the freshness drops, the eggs will dry out and the surfaces will dimple, wrinkling. This is the type of ikura that is cheaper and often served at the cheap conveyor belt sushi restaurants.

The most commonly used roe in conveyor belt sushi restaurants is ikura from cheap Alaskan or Russian Chum salmon. An even cheaper type is masuko. Besides the masu roe, raw materials included soy sauce, salt, fermented seasoning, amino acids, reduced sugar syrup, enzymes, fish sauce, and fish and shellfish extract. For homemade versions, only soy sauce, mirin (sweet cooking sake) and sake are used.


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Revision date: March 9, 2021

What is Salmon caviar?

In Japan, salmon roe that has been separated from the ovarian membrane and then salted is called ikura. At sushi restaurants, this is also marinated in broth that includes soy sauce, mirin and sake. This is called ikura marinated in soy sauce, or simply ikura. Worldwide, caviar is considered to be of more value than ikura. Therefore, in an attempt to improve the impression of soy sauce-marinated ikura, it is sometimes called ‘salmon caviar’. This is behavior especially seen among manufacturers selling soy sauce-marinated ikura.


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Revision date: March 9, 2021

What is Red caviar?

Not to belabor the point, but the following is dependent on the following. In Japanese salmon is referred to as “鮭” (sake/salmon) or “鱒” (masu/trout). The characters look different, but they are part of the same family and there aren’t clear biological categories to separate them into. Incidentally, in English the type that makes their way into the sea are called “salmon,” and those that remain in freshwater their entire lives are known as, “trout.” They are all considered to be part of the salmon family. Now, foreigners who know about Japan may imagine Japanese sake (the alcoholic beverage) when they hear the word “sake” so we spell sake/salmon as “shake”, which is close to the sound pronounced by Japanese people.

First of all, shake is mainly Chum salmon, caught in the seas near Japan. Masu caught in the seas near Japan are mostly Pink salmon (Humpback salmon) and Sakura masu. Masu caught in rivers and lakes are generally Char or Rainbow trout.

Now we finally get to the topic of this article, shake roe that has been removed from the ovarian membrane then salted or marinated in soy sauce is called ikura while masu roe is called masuko and they are clearly distinguished. This is because masuko can be bought at just 20-40% of the cost of ikura. However, the difference is really that each egg is smaller than that of ikura and in general people can’t taste a difference.

Over the past 10 years or so, the masuko made from the roe of Rainbow trout farmed in France and the masu farmed in Japan have been called ‘red caviar’ by manufacturers. Of course black caviar made from the roe of sturgeon and tobiko made from the roe of flying fish are distinctive. Certainly there is no problem in calling fish roe caviar according to the Product Labeling laws, but it’s extremely clear that they are only trying to get a higher price out of it.


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Revision date: March 9, 2021

What is ken?

Ken is considered to be better the longer and thinner it is, but this is a mistake. Not only is Ken tangled and difficult to eat, but it also doesn’t give any sense of the flavor of the materials. It’s long been said that 10 cm is a reasonable length and this is also the length that looks the most refined.

Many people believe that the thinly cut daikon radish strips that accompany sushi are tsuma. That is not tsuma. It’s called ken. Besides daikon radish, udo, pumpkin, cucumber, carrots and turnips are also used. It is cut into thin strands and stood up next to sashimi like a sword (which is called “ken” in Japanese). However, when the sashimi is laid on top of it, it is called shikitsuma. While it is a bit confusing, in that case it is a type of tsuma. Since the Meiji era, combos of many different types of sushi have become popular, and with it larger dishes have become necessary. Therefore, there has also been a tendency to make it more showy. It’s only natural that the types of tsuma increase to place focus on the highly valued seafood, but if there is too much ken, it will take over the space meant for the sashimi.


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Revision date: March 8, 2021

 

What is the difference between denbu and oboro?

Oboro and Denbu look the same, and the ingredients are also pretty much the same. In other words, there are no clear differences between them, but what it is called differs depending on the restaurant’s policy and the locality. There are various theories for this, but there is no clear line distinguishing oboro and denbu.

Denbu (田麩) is mainly boiled white fish that is then loosened and made into fibers, then seasoned with sugar, mirin, salt, etc., then roasted until the moisture is gone. Some are colored with red food coloring (called sakura denbu) while others are left as the brown color similar to tsukudani. The appearance is as if only the fibers of the original ingredients remain. This is why it was written with the kanji “田夫” (the literal meaning of kanji: rice patty+husband). The word “田夫” means “someone from the countryside” or “rough-cut” and refers to the way the fish is turned into a coarse form by pulling the meat apart. It is also used as a coloring for chirashizushi, futomaki (large sushi rolls), bento boxes, etc.

On the other hand, Oboro (朧) is made by using a grinding bowl to break down the meat of shiba shrimp or white fish, then seasoning with sugar, mirin and salt before removing the moisture over low heat. Oboro is used for bara-chirashi, futomaki (large sushi rolls), etc., and is also sometimes used between the topping and shari (vinegared rice) in nigiri sushi. This gentle sweetness and the shrimp aroma are essential for Edo-style sushi. Making oboro is laborious work, so there are fewer and fewer Edo-style sushi restaurants that make their own oboro.


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Revision date: February 1, 2021

What is Fugu poison?

In most cases, Fugu (blowfish) poison is found in non-meat parts of the fish such as the liver, ovaries, stomach, intestine, skin and eyes. There are Fugu that do not contain poison in these parts, but most of the Fugu in the waters near Japan are poisonous. A mistake in preparations that allows the meat to touch the poison of the liver or ovaries results in immediate death. Therefore, the general rule is to only eat Fugu at restaurants with an expert licensed in Fugu preparation. Cases of poisoning by Fugu are nearly always a result of an amateur trying to prepare the fish.

The toxin in Fugu is a chemical substance called tetrodotoxin and even heat from boiling or frying can’t detoxicate it. Even Torafugu (Japanese pufferfish) that we find so delicious (we eat the meat, skin and testes) has poison in the liver, ovaries and intestines. The toxicity is said to be at least 1,000 times that of potassium cyanide. They say 10 people would die from the organs of a single Torafugu. In the case of Fugu poisoning, the first poisoning symptoms occur between 20 minutes and three hours after eating the Fugu. It starts with numbness in the lips, the tip of the tongue and fingertips. This is followed by headache, stomachache and severe vomiting. The victim will stagger when trying to walk. Soon they will experience sensory paralysis, speech disturbance and difficulty breathing, accompanied by a decrease in blood pressure. After that, the entire body becomes paralyzed and the victim can no longer move even a finger. Finally, they will fade out of consciousness and eventually both breathing and heartbeat cease, resulting in death. If the consumer doesn’t notice they are experiencing poisoning symptoms, they will surely die.

The strength of the toxin of the fugu also varies depending on the season. Even on an individual basis, some fish have toxins while others don’t. It’s not possible to determine this based on appearance, so it’s better to never eat the organs and eyes, which have a high probability of containing poison.

Fugu has already been successfully farmed and is on the market. No toxins have been found in this farmed Fugu. If farmed Fugu has no toxins, it’s only natural to question what factors generate toxins in wild Fugu and apparently it‘s a cumulative effect of toxins from the food chain. Fugu’s main sources of nutrition are starfish and shellfish. Starfish and shellfish accumulate poison in the body by eating zooplankton with vibrio attached to them. This vibrio creates poisons. Then, Fugu accumulates toxins in the body by eating starfish and shellfish that have toxins accumulated in their bodies. Therefore, farmed Fugu are raised on man-made feed that doesn’t contain Fugu toxins, and since they don’t ingest Fugu toxins and there is no bioconcentration, so the Fugu does not contain poison.


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Revision date: February 1, 2021

What is Shusseuo?

During the Edo period, samurai would change their names at Genpuku (coming-of-age ceremony and career stages. Fish that are called by names as they grow older/larger are called “shusseuo (出世魚)”, are considered lucky and are used in cooking to celebrate milestones in life.

Shusseuo doesn’t just change in name, they also change in taste. The bigger the body, the more fat. However, young fish also have their own delicious, refreshing taste unique to their age. For example, using the young fish for deep-frying and fatty fish as sashimi is an interesting way to put it.

Shusseuo is not the only fish called by different names as they grow. According to the “Study of Japanese Fish Names”, there are 82 types of fish that are called by different names as they grow. Kuromaguro and kanpachi are popular examples. Kuromaguro changes from Komeji to Meji to Maguro and then to Oomaguro. Kanpachi changes from Mojako to Shiwoko to Akahana and then to Kanpachi. Even konoshiro, sawara, unagi, shake, koi, etc. are not shusseuo. Generally, it’s not those fish that are called by different names according to their growth stage that is called shusseuo. Fish that taste better as they grow, that changes little over time, and have been valued since eras when preservation and transport were not well-developed, are called shusseuo.

A good representative fish of shusseuo is the yellowtail. Its name changes as it grows and there are various forms of their names depending on the region. In the Kanto region, it changes from Wakashi (15-20cm) to Inada (30-40cm) to Warasa (60cm) and then to Buri (80cm or greater). It is said to be most delicious at 40 cm or longer and even if the body is plump, inada often has little fat.

Even if the name is the same, depending on the region, it may be referring to a different size. For example, inada is a fish up to 40 cm in Kanto but in Tohoku and Tokai, it refers to small fish of 15-20 cm. Further, although it is not related to its growth, those caught in Tohoku during summer are called “ao”. In Toyama, they are called “gan” and “gando”.

Finally, the changing names of fish demonstrate the breadth of culture. We should cherish this local diversity present in the names of our fish that capture the abundant food culture and importance of the seasons.


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Revision date: January 5, 2021

What is Artificial caviar?

Caviar refers to salted sturgeon ovaries but in many European countries, caviar is also used as a generic term for fish roe. In its home of Russia, roe is generally called “ikura” and caviar specifically refers to black fish roe.

Caviar is one of the world’s three major delicacies and can command different prices depending on the type of sturgeon (egg size). It is ranked in the order: Beluga, Oscietra and Sevruga, all of which come from the Caspian Sea. Beluga from the Caspian Sea is designated as an endangered species and international trade is prohibited by the Washington Convention. Its population is very small and it does not lay eggs until 20 years into its lifespan, so the resource has yet to recover. This has brought the market price of Beluga up to around USD $400 for just 50 g.

What is the substitute for caviar?

Lumpfish roe is sold as a substitute for caviar. The size of each egg is about 2 mm in diameter and it is colored with squid ink. This gives it a taste and appearance similar to caviar. The market price is an astonishing USD $5 per 50 g.

The main ingredients of Lumpfish caviar are as follows:

  •  Lumpfish roe
  •  Salt
  •  Sugar
  •  Thickening agent
  •  Sodium benzoate
  •  Coloring

What is artificial caviar?

Artificial caviar is significantly cheaper than genuine caviar. It’s low in fats, lower in calories and healthier than the real thing. It is already a big hit in the U.S. The size of the eggs is a little larger than authentic caviar and the skin is thicker but most people would tell you the texture and taste is much the same. There has also been a decrease in sturgeon, and there is no sign that its price will fall in the future. The challenge is meeting the global demand through a combination of farmed caviar which has become a more stable supply in recent years, with the ever-dwindling wild caviar. The market price is reasonable at around USD $10 for 50 g.

The main raw ingredients of artificial caviar are as follows:

  •  Sea urchin extract
  •  Oyster extract
  •  Gelatin
  •  Dextrin
  •  D-sorbitol
  •  Trehalose
  •  Gelling agent
  •  Seasoning
  •  Coloring

Finally, seafood with a high price, unfortunately, results in substitutes, counterfeits, and artificial products. Masquerading a fake as the real thing can result in a large profit. I will tell you that it is difficult to trick a middleman who serves professional sushi chefs or restaurants. Therefore anyone in Japan who uses seafood like this, does it knowingly, which makes the crime even worse.


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Revision date: January 4, 2021

What is Izumidai?

When you see “tai” on the menu at a conveyor belt sushi restaurant, it’s very likely that is not “madai” (Red sea bream). It’s a competitive industry where these conveyor belt restaurants have no problem using a variety of imitation or replacement fish if it means they can cut costs. In any case, the purpose for using different types of fish without even considering farmed cheap madai, is to further reduce costs.

First on the list is Nile tilapia. This fish was introduced from Egypt to rivers throughout the world as food in 1962. While it was farmed in large quantities in Japan, especially in Kagoshima, from the 1990s, production rapidly declined with the stagnant prices of farmed madai. However, they are extremely fertile and proliferate naturally, and started living in the thermal regions and the rivers where warm wastewater flow throughout Japan.

The commonly used names for this is “izumidai” or “chikadai”. While izumidai (Nile tilapia) is a freshwater fish, it was likely named after “tai” (sea bream) because of the similarities in appearance. In Taiwan, it is considered to be so similar in appearance and taste, that it is called “Taiwanese sea bream”. It is a popular fish for consumption on a global scale with high production and distribution volume.

However, even though has “sea bream” in the name, it is not actually related to the sea bream at all.

As an aside, at least 90% of the tilapia found in the U.S. is imported. Most of those imports come from China. It’s often said that they are raised on a large volume of antibiotics and pesticides, and they are kept fresh using high amounts of chemicals. It’s best to avoid eating it if possible. The tagline they give it is “Sushi grade tilapia is a high quality, firm fish with a mild, clean taste perfect for sashimi and sushi applications” You’ll be hard-pressed to even find kaiten sushi restaurants using this in Japan. In addition, it would never be used at restaurants that describe themselves as Edomae Sushi.


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Revision date: January 4, 2021

 

What is engawa?

Engawa has both a unique, crunchy texture and delightful fat distribution and is said to be the most delicious part of hirame.

But what exactly is engawa?

Engawa is the generally used name for the meat muscle that moves the soft ray of the dorsal and ventral fins of flatfish (such as hirame and makogarei). Most people in Japan think of the hirame version when they hear the word ‘engawa’.

To go into a more advanced level of detail, there are three types of muscles that move the dorsal and ventral fins in fish: the erector spinae, the depressor and the scalene muscles. These muscles are well-developed in fish that move their dorsal and ventral fins often, like flatfish and flounder. Actually, not all three of these types are always consumed. If we look at the way hirame and makogarei are cut for preparation, the slanted muscle is taken to be used for engawa while the erector spinae and depressor are left, affixed to the fin ray, etc. In other words, to be exact, engawa is the slanted muscle of the dorsal and ventral fins.

The unique, crunchy texture comes from the high content of collagen, which is a scleroprotein. “Kakushi boucho” is used to make the crunch pleasant and is one of the skills a sushi chef must perfect. The delicious flavor is related to the high amount of fat compared to body meat. There is also a sense of elegant sweetness. Only four pieces of engawa can be taken from a single flatfish, so it makes sense that foodies love it.

The name “engawa” comes from its resemblance to the unique veranda structure of Japanese-style homes. This veranda is called “engawa” in Japanese.

Incidentally, substitutions have become common at kaiten sushi (conveyor belt sushi) restaurants, and the topping is especially popular among women lately. So the question is, how is it possible to eat this valuable topping that is only rarely available at expensive sushi restaurants, so cheaply at kaiten sushi? Actually, Greenland halibut engawa and Kamchatka flounder engawa are used as substitutes to hirame engawa. The proof of this is in a menu that lists only “engawa” and not “hirame engawa”.


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Revision date: December 3, 2020

What is the difference between Fish farming tuna and Fish fattening tuna?

While high-quality tuna toro used to be unattainable for normal people, it’s now become a much more affordable item. This is thanks to fish fattening practices of the southern bluefin tuna, which is equivalent in quality to the Pacific bluefin tuna. The fattening method of catching young southern bluefin tuna in roll nets or something similar, and then keeping them in fish preserves until they grow big enough was developed in the 1990s in Australia.

There have been changes in the Pacific bluefin tuna as well. In the late 1990s, the southern bluefin tuna fish fattening method started to be used in the seas throughout the world, and this led to the fattening of the Pacific bluefin tuna, which became all the rage. Most of these are exported to Japan, and account for about half of the consumption of southern bluefin tuna and Pacific bluefin tuna in Japan.

As a bonus, tuna that has been fattened in this way has such a high volume of fat that it is said to be “all toro”, and it’s taken the Japan high-grade toro market by storm. Also, both southern bluefin tuna and Pacific bluefin tuna are served at kaiten-zushi (conveyor belt sushi) restaurants.

The fattening of Pacific bluefin tuna started on the east coast of Canada in the mid-seventies. In the summer, large volumes of Pacific bluefin tuna are caught in the fixed shore nets on the Atlantic seaboard, and since they have already spawned, they have slimmed down and aren’t worth much commercially. These fish are fed and fattened, and a new route to Japan has been developed, giving the fish new commercial value.

Both fish fattening and fish farming mean to hold fish in fish preserves, but the purpose differs between the two. The purpose of fish fattening is an adjustment for fishing while the purpose of fish farming is to grow fish to a certain size. Therefore, in fish fattening, they are not fed food to promote growth, but they are in fish farming. However, even in fish fattening, if the period of time they are held for shipping adjustment stretches out too long, they are fed in order to prevent a decrease in meat quality and cannibalism. This can blur the line between fish fattening and fish farming quite a bit.

The Pacific bluefin tuna fish fattening started in Canada is similarly vague. In that case, the purpose was fattening, so it may be fair to call it fish farming. However, shipping adjustment was also one of the major objectives. What about the fish fattening of southern bluefin tuna and Pacific bluefin tuna in Australia and the Mediterranean Sea? These are in place clearly for the purpose of growing small fish, so we can call them fish farming.

The Kindai University Aquaculture Research Institute has succeeded in a complete farming process of taking eggs from spawning Pacific bluefin tuna, incubating them and raising adult fish. Research for a complete farming process began around 1970, so it has taken 30 years for success. These fully farmed tuna are also raised in fish preserves and fed small fish like sardines as well as artificial feed for fattening, resulting in all-toro tuna. However, even though the Kindai University tuna have been featured by the media, you never see them in the supermarket. Why is that? Even though the university has succeeded in a mass-production method, the absolute quantity is extremely low even though raising the fish takes a lot of time and effort, so the price is extremely high.

Whether they are fattened, farmed, or fished in the wild, consumers always welcome delicious, high-quality toro at a reasonable price.


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Revision date: December 1, 2020

What is a firm difference between sushi and western fish cuisine?

In Japan, they say, “Japanese cooking means taking away and Western cooking means adding.” This concept is well-known among Japanese chefs, but it may be difficult for western chefs to understand. This is verified in the way the white Japanese sea bass, the representative fish of summer, is prepared. This is all connected to clearly explaining the irrefutable differences between sushi and western fish cuisine, which also involves differences in cultivated history and culture.

In the case of Sushi, a representative of Japanese cuisine, the decisive point is to prepare the fish in a way that removes the fishy odor characteristic of Japanese sea bass. At the same time, the finished piece should be a simple dish that can be enjoyed with only a minimal amount of nikiri soy sauce and wasabi, so as not to override the natural refreshing flavor and umami of the fish. It should let the customer imagine sea bass swimming in the summer sea. And yet, the deep flavor required for the dish is successfully brought out using only a balanced combination of vinegar rice, the topping, wasabi and soy sauce. The method is really just to take out the excessive elements of the dish.

Meanwhile, the method for making sea bass dishes in French cuisine, representative of western cooking, includes seasoning the fish with salt and pepper and saute in butter, then adding rich, creamy sauce as well as other things like herbs, caviar, black truffles, etc., creating a dish that allows enjoyment of multilayered flavor. This sort of dish beautifully makes up for the flavors that the light, white fish lacks and portrays a flavor with depth through the finished plate over the individual flavor of the sea bass. In this cuisine, it can be said that the cooking method is more important than the raw ingredients. It can be thought of as cuisine that adds many ingredients.

Comparing the two, it’s clear that the approaches are completely opposite. Another difference is how the flavors are treated. Flavors that are experienced by “fragrance” can be defined as “fragrant flavor”.

If this fragrant flavor were not important in sushi, then there would be no debate on whether to use wild or farmed fish. For example, sea bream is available both in the wild and as farmed fish. There is not much difference in amino acid composition and umami content between the two. So how is it that farmed sea bream and wild sea bream end up tasting so different? The reason is undoubtedly the fragrance. The subtle fragrance components in the fat of the sea bream determine the essential flavor of the fish. You can’t expect to get this flavor from a farmed fish. Doesn’t that mean that the pleasure of eating sushi comes from the awareness of this fragrance?

On the other hand, in Western fish cuisine, the culture is to combine many different fragrances, as if concocting a perfume, probably because people want complex flavor. In addition, in French and similar cuisines, care to serve dishes at a temperature that is warm, but not hot, in order to bring out the natural flavor of the ingredients. While cooking the dishes, the temperature is strictly controlled so that the components of the ingredients don’t change from the heat, in order to maintain the taste and fragrance. This method does not neglect fragrance by any means.

In either method, the one essential element is this “fragrance”. The only true difference is how that is expressed.


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Revision date: November 2, 2020

How can frozen tuna be thawed to still taste good?

In order to maintain the quality of tuna, when it is caught in the sea, the ikejime technique is used first, then rapid freezing is used as a matter of course. This means that the quality of the thawing technique is also important. Poor thawing conditions mean that the drip outflow volume will be too high, shrinking the meat and worsening the texture. Here I will explain a thawing method that doesn’t cause drip, uneven thawing, or loss of color.

What exactly is drip anyway?

I’m sure you’ve seen it before in any type of thawing frozen meat, but there is a red liquid that comes out of the tuna when thawing. This is called ‘drip’. This liquid includes the tuna’s umami, and when the fish loses a lot, it naturally detracts from the flavor.

First of all, we will explain the worst thawing methods. Never thaw naturally at room temperature or in the microwave. These are common methods at home, but they are out of the question.

Next we will explain the general method of thawing.

  1. Mix 30 g of salt with 1000 cc of warm water at 40℃ to create a saltwater mixture.
  2. Place the frozen block of tuna in this 40℃ saltwater, submerge for one to two minutes and then drain the water.
  3. Wash any remaining salt off the surface of the block of fish with fresh water and remove moisture from the surface with paper towels.
  4. Wrap the fish in clean paper towels, wrap with plastic over that and leave it in the refrigerator for about a day to thaw naturally.
  5. Cut from the block directly before consuming.

Now for the thawing method used by professionals, such as sushi chefs.

The first three steps are the same as the general thawing method above.

  1. Place block in an air-tight plastic bag. Push out as much air as possible before sealing the bag.
  2. Prepare ice water in a bowl or container and submerge the plastic bag in the water for one hour. Normally the bag will float, so it must be weighed down with something.
  3. Remove the thawed tuna from the plastic bag and remove moisture with paper towels.
  4. Wrap the fish in clean paper towels, wrap with plastic over that and leave it in the refrigerator for about a day to mature.

After thawing, the meat of the tuna may have shrunk. This is called ‘chijire’. The reason for this is, after the tuna is caught, it is frozen before rigor mortis begins, so the rigor mortis process starts once the fish is thawed. Therefore, this is proof of freshness. The meat of tuna for which ‘chijire’ has begun is tough and isn’t yet matured. However, amateurs can’t tell if ‘chijire’ is happening or not. That’s why it’s better to let the fish mature in the refrigerator for half a day to one day. Please use these explanations for your own reference.


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Revision date: October 2, 2020

What’s the trick to distinguishing which conveyor belt sushi restaurants are better?!

There is only one trick to distinguishing between conveyor belt sushi restaurants (kaiten-zushi), and that is to try eating the tuna as your first dish.

Why is that, you ask?

The most commonly used ingredient at kaiten-zushi is tuna. At kaiten-zushi, the tuna is imported and frozen nearly 100% of the time. The most famous is the Southern blue-fin tun, but you’ll also find Boston bluefin tuna, Canadian tuna farmed in fish preserves, inland sea tuna from Turkey and Spain, New Zealand offshore tuna, Atlantic tuna, etc. Also, the season of each type of tuna and the timing of high-volume catch differ, which makes the prices fluctuate greatly.

Therefore, the biggest task of a kaiten-zushi chain buyer is to decide where to import tuna from. Looking for high cost-performance, they watch fluctuations in the market every single day without fail, check the flavor in detail and constantly change the locality.

In other words, the chain restaurant purchaser’s efforts are concentrated on tuna. Restaurants that serve tuna that has lost its fat, is watery or rubbery, clearly either have a purchaser with a poor eye, or poor thawing skills. Therefore, if you are disappointed with that first tuna plate, then reign in your expectations for other toppings. On the other hand, if you enjoy the tuna then you’ll have a lot of other toppings to look forward to.


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Revision date: August 17, 2020