What is Albino rainbow trout?

a photo of Albino rainbow trout
Other Albino fish have a white body color, but the Rainbow trout has a yellow body color.

There is a Rainbow trout with yellow body color.

This is the Albino rainbow trout.

The Albino has no pigmentation. Other Albino fish have a white body color, but the Rainbow trout has a yellow body color. Since its first discovery in 1956 at the Fisheries Experiment Station in Nagano Prefecture, Japan, experiments conducted by crossbreeding Albino with other Albino or Albino with ordinary Rainbow trout have shown that it is genetically dominant. Pure descendants of the Albino are now being produced in aquaculture farms throughout Japan.

Albino is rarely found in the normal production of Rainbow trout in aquaculture farms. Albino is a mutation of the Rainbow trout that lacks tyrosinase (An enzyme that breaks down tyrosine, a type of amino acid, to produce melanin). This prevents the production of melanin, a black pigment, and causes the trout to turn yellow. The yellowish coloration is thought to be due to the other pigments that remain after the melanin-black pigment is gone.

Normal Albino is genetically recessive, so if both parents are not Albino, their offspring will not be Albino. However, Albino rainbow trout is dominant, so if either male or female parent is an Albino, their offspring will be born as an Albino.

Neither the albino rainbow trout nor the blue rainbow trout is a protective color, so if it were to occur in nature, it would have little chance of surviving due to bird damage.

Albino rainbow trout has little edible value but is released for recreational fishing because of its scarcity. In fish farms, it is sometimes used as a visible indicator of growth. There may be some differences in taste, smell, and texture, but these are within the range of individual differences. And Sushi chefs do not use Albino rainbow trout for sushi.

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Revision date: April 7, 2023


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What is Shiba shrimp (Shiba-ebi) sushi?

a photo of Shiba ebi
Even if you look at it favorably, the color of Shiba shrimp (Shiba-ebi) does not make it look delicious.

What is Shiba shrimp (Shiba-ebi)?

Shiba shrimp (Shiba-ebi) is distributed south of Tokyo Bay on the Pacific Ocean side, south of Niigata Prefecture on the Sea of Japan side, and along the coast of China. It lives in sandy mud at depths of 10 to 30 m in inner bays, and grows to about 15 cm in length. The shell is thin, without stripes, and light yellowish-gray in color. They are also called Akahige (Aka means red and hige means antennae.) in some regions because of their red antennae. The season is from November to March. It was once caught in large numbers off the shiba coast of Tokyo Bay, hence the name shiba-ebi. It is important to note that Shiba shrimp lose their freshness quickly and the heads darken quickly, so they should be cooked on the same day or the heads should be removed. The main production areas are the Ariake Sea in Kyushu and Mikawa Bay in Aichi Prefecture. Its scientific name is Metapenaeus joyneri (Miers.1880).

 

What does Shiba shrimp (Shiba-ebi) sushi taste like?

a photo of Kakiage
Recently, whiteleg shrimp, which is less expensive, is used as an ingredient in Kakiage (seafood tempura) instead of Shiba shrimp.

Shiba shrimp is generally used in seafood tempura, Chinese cuisine, etc. When made into sashimi, it has a light and elegant taste, but the texture and sweetness are not quite enough.

a photo of oboro nigiri
Some sushi chefs serve Oboro nigiri like a dessert at the end of the meal.

It is not a typical ingredient for Nigiri sushi, but it is indispensable at sushi restaurants. It is used as an ingredient in Oboro and Tamagoyaki. Rarely, you will see sushi chefs making Gunkanmaki, but it looks grayish-white and not very tasty, and the delicate taste of Shiba-ebi is masked by the flavor of the nori seaweed.

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Revision date: April 5, 2023


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What is Sweetfish (Ayu) sushi?

a photo of Ayu (Sweetfish)
A small sweetfish is used for nigiri sushi.

What is Sweetfish (Ayu)?

Sweetfish (Ayu) is distributed throughout East Asia from southern Hokkaido to Kyushu, the Korean Peninsula, and northern Vietnam. The species found on Amami-Oshima Island and Okinawa Island is called Ryukyu-ayu and is a differentiated subspecies. Ayu is characterized by the oval yellow spots on the upper pectoral fins and a dozen rows of comb-like teeth aligned on the lip.

It is born near the estuary in the fall, goes down to the sea to overwinter, returns upstream the following spring to become an adult, and then migrates back downstream to spawn and live out their lives. In some lakes, such as Lake Biwa, a land-locked type is found that completes its life in the lake instead of the ocean. These groups are called Ko-ayu. Aquaculture is also popular, with Gifu, Hiroshima, Kochi, and Kyushu being well-known production areas. The scientific name is Plecoglossus altivelis altivelis (Temminck and Schlegel, 1846).

The traditional names used to describe the fish are “Kou-gyo (fragrant fish)“ (because of its unique scent), “Nen-gyo (annual fish)“ (because it usually lives only one year), “Ginko-gyo (silver-lipped fish)“ (because its mouth glows silver when it swims), Keiun (means sardine in a mountain stream) and “Sairin-gyo (scaled fish)“ (because of its small scales).

What does Sweetfish (Ayu) sushi taste like?

a photo of Ayu sushi
When making nigiri sushi, the head of the ayu fish is sometimes left on or the skin is removed.

Adult ayu feeds on algae on the surface of stones in the river, giving them a distinctive aroma like that of watermelon or cucumber, which can already be smelled even by young fish in the upstream season. The season is from July to August when ayu put on fat, but the aroma is stronger when young ayu are caught a little earlier.

When preparing nigiri sushi, small wild ayu is used, the head and entrails are removed, and the belly is cut open and the inside bone is removed. In traditional Ayu sugata sushi (whole fish sushi), the fish is thoroughly salted to drain off the water and make it strong sujime. Then let it rest in the refrigerator for half a day. If the fish is small ayu, the skin can be left on, but if the size is large or the sushi is to be made immediately after soaking in vinegar, the skin is often felt hard, so it is removed. Ayu belongs to Hikaramono in the sushi category, perhaps because of its shiny appearance. There are very few sushi chefs who make Ayu’s nigiri sushi, so Sushi Sanshi (鮨三心), Sushi Ikko (鮨一幸), Kanda Sasazushi (神田笹鮨), etc. have it on their signature menu. It was the most popular autumnal sushi item during the Edo period.

a photo of Ayu shioyaki
When eating salt-grilled ayu fish, it is good manners to taste the whole fish, but the head and tail can be left behind.

To enjoy the elegant appearance and aroma of ayu, grilled with salt is the best way to go. The fish is put on a skewer in such a way that their body forms a wave, making them look as if they are swimming (it is called uneri gushi). It is traditionally eaten with water pepper vinegar, which goes well with it.

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Revision date: July 4, 2023


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What is Stone flounder (Ishigarei) sushi?

a photo of Stone flounder (Ishigarei)
Sushi aficionados will appreciate it as a truly extravagant sushi nigiri.

What is Stone flounder (Ishigarei)?

Stone flounder (Ishigarei) is distributed along the coasts of Japan, the Kuril Islands, Sakhalin, the Korean Peninsula, and Taiwan. It lives in sandy mud at depths of 30 to 100 meters, and its total length reaches 50 cm. The body surface is smooth with no scales, but there are large longitudinal bony plates on the dorsal surface of the body on the eye side and other small bony plates. In Japan, depending upon the region it will be called other names, such as Ishimochi, Ishimochigarei, or Shirogarei.

It was caught in large quantities by bottom trawling fishing and was synonymous with cheap flounder. However, since the Edo period (1603-1867), it has been treated as a luxury fish in Tokyo. This is because white fish are scarce in summer, and even now, as summer approaches, the price rises along with Japanese sea bass (Suzuki) in the market. However, there was a time when it became a phantom fish that could not be caught at all due to the reclamation and development of Tokyo Bay that began after World War II.

What does Stone flounder (Ishigarei) sushi taste like?

Stone flounder is made by quickly removing the bony plates during the preparation process to avoid the characteristic muddy smell of flounder. It has clear, elegant flesh with a moderate aroma of the sea and a rich flavor with just the right amount of crunchiness. It caught in Tokyo Bay is highly prized and is served as sashimi and sushi, but it is also delicious simmered, or grilled.

As a rule, only live fish can be used for nigiri sushi. Nojime and Ikejime are also not highly valued because the umami component of flounder rapidly decreases after death. Stone flounder, which can be found in abundance in supermarkets at reasonable prices, cannot be used for nigiri sushi or sashimi. It also has a distinctive odor when it is no longer fresh, so it is best to remove it quickly and remove the skin. Skinless fillets can be enjoyed even after maturing for a while.

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Revision date: March 17, 2023


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What is real Omakase at a sushi restaurant?

Omakase sushi experience
She is very interested in eating sushi toppings for the first time.

We’ll start by breaking down the meaning of this word in Japanese.

The “O” of “Omakase” is a prefix generally used as an honorific expression. The meaning of “makase” refers to a judgment of things and means to entrust a task you were meant to do to someone else, allowing them to perform the task at their own discretion. In terms of sushi, while a customer normally chooses which toppings they want to eat on their own, a customer with limited sushi topping knowledge may ask the chef to prepare his own recommendations.

There are various other ways to order sushi toppings as well. First, sushi restaurants generally have a set menu called “Okimari.” For example, let’s consider an Okimari set that contains 8 pieces of nigiri sushi. This set of 8 pieces will contain the same toppings and maintain the same price throughout the year. In contrast, a customer may choose the number of toppings they like in whatever order they prefer, such as ordering two pieces each of four types of toppings, which is called “Okonomi.” They can even order eight of the same topping. The price for “Okonomi” depends on what is ordered, the more expensive the toppings are, the higher the price will be. For “Omakase,” the chef would select 8 toppings and serve them in his recommended order. However, the customer conveys their budget to the chef in advance so the sushi course can be provided within that budget. The customer can also specify toppings they prefer to avoid. In other words, you need to let the chef know in advance about your budget according to the market, and any requests (For example, I would like to eat the Splendid alfonsino (Kinmedai) in season) that you can’t budge on. You don’t need to leave those two things up to the chef’s discretion.

Now, in actuality, there are many sushi restaurants that stray from the original definition of “Omakase.”

For instance, he/she may include Tsumami as part of the course, rather than only sushi. This would be Sushi Kappo (sitting at the counter to enjoy Japanese food and served directly by the chef). A sushi restaurant was once a place where only Nigiri sushi was served. To explain in more detail, if only Nigiri sushi is served, then even if you were to eat 20 pieces of Nigiri sushi, your time in the restaurant would only be around 30 minutes (this is true the case of the establishment of the famous Jiro). Nowadays sushi restaurants are used for entertaining business clients or going on dates, so the customer may stay for around two hours. In situations like this conversation is the priority, so the actual ordering of the sushi takes the backseat. Incidentally, the practice of drinking Japanese sake at sushi restaurants is said to have begun around 1910.

Next, we’ll let you in on a common misconception that you probably don’t want to hear.

Apparently, people believe that ordering Omakase means that you will be served rare pieces that are not disclosed on the menu. Some are even convinced that they can get more expensive toppings than they would if they ordered with the Okonomi method. However, the restaurant just sets the price for the Omakase course and just adjusts the menu items accordingly (to suit the budget) based on current stock. The benefit to the restaurant is that it only stocks the amount of seafood necessary and will waste less. Unfortunately, rare finds are reserved for customers who know what they like. Go ahead and toss any such expectations out of your mind right now. Instead, acquiring sushi knowledge will allow you to avoid being recommended toppings that are approaching expiration.

Finally, if you just get an expensive Omakase course without understanding where the toppings came from or when they are in season, then it won’t contribute to your deeper understanding of the magnificence of Nigiri sushi.

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Revision date: April 18, 2023


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Nigiri sushi should be eaten when the fish is in season!

a photo of Mackerel
Mackerel is now in season.

Each food has its own season. It goes without saying that the taste is at its best at that time of year.

When is this “season”?

Most people would answer that it is the time of year when food can be harvested in abundance. This is certainly true for fruits and vegetables. However, this is not always the case with fish. Fish season refers to “the time when the fish is at its peak of fat content,” which does not necessarily coincide with the time when the food is in abundance.

Then, what determines when fish are in season, is the relationship with the spawning season, which is the most important factor. One to two months prior to spawning, both male and female fish feed frantically. This is the time of year when the fish are fat, fatty, and delicious. This is the fish’s season.

However, when the spawning season arrives, the fish become thin. This is because all the nutrients in the body are absorbed by the testes of the males and the eggs of the females. Especially immediately after spawning, the fish have used up all their energy, and their flesh is in a very shabby state.

In other words, the timing of eating the fish is off by just a few days, and the fish tastes considerably less good than when it is in season.

We think you get the idea by now.

You are bound to order fish out of season due to your lack of knowledge. To avoid wasting your money, you should know the season of typical sushi items.

The seasons of typical fish are as follows.

Spring: Japanese halfbeak (Sayori), Ark shell (Akagai), Red seabream (Tai), Pacific herring (Nishin), Black Rockfish (Mebaru), Firefly Squid (Hotaru ika)

Summer: Japanese conger (Anago), Bonito (Katsuo), Horse mackerel (Aji), Greater amberjack (Kanpachi), Goldstriped amberjack (Hiramasa), Daggertooth pike conger (Hamo), Japanese sea bass (Suzuki), Sea urchin (Uni), Japanese whiting (Kisu), Chicken grunt (Isaki), Common scallop (Hotate)

Autumn: Pacific saury (Sanma), Mackerel (Saba), Gizzard shad (Kohada)

Winter: Bastard halibut (Hirame), Japanese amberjack (Buri), Bluefin tuna (Kuro maguro), Japanese pufferfish (Fugu), Splendid alfonsino (Kinmedai), Golden cuttlefish (Sumi ika)

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Revision date: February 27, 2023


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What is Katsuobushi?

a photo of Katsuobushi
Of the ingredients used to make dashi, katsuobushi is the most common.

Katsuobushi (鰹節) appears frequently in documents from the Muromachi period (1333-1573) and later, and was used then, as it is now, to take dashi. The name Tosa-bushi is also found in documents from the early Edo period (1603-1868), but the method of making it seems to have been to boil it down and then dry it in the sun, and it is said that the current molding method was invented around 1673~81. In the Tosa Domain, which has been famous for bonito fishing since ancient times, Harimaya Sanosuke of Usa and Yamazaki Giemon of Nakahama worked to improve and popularize Tosa-bushi, and the name Tosa-bushi spread as a specialty of the domain in Edo and Osaka.

The process of making katsuobushi begins by boiling the formed bonito meat in boiling water, removing the bones and some of the skin, placing it in baskets, and then placing it in a chamber to be heated and dried over a fire made of oak, sawtooth oak, or kashiwa (oak tree). This is called Baikan (焙乾).

At this stage the product to be shipped is called Namabushi. The first Baikan is called Ichiban-bi. After that, the cracks and missing parts of the Fushi are repaired with bonito surimi. The baikan is repeated once a day for 2 to 12 times. In case you are wondering, Katsuobushi before shaving is called Fushi.

After Baikan, it is called Arabushi (荒節) or Onibushi (鬼節). After drying in the sun for a few days, the surface is scraped with a small knife and called Hadakabushi (裸節), Akamuki (赤むき), Wakabushi (若節), Shinbushi (新節), etc. After drying in the sun again, it is placed in a wooden box called Kabi-tsuke-bako for 15 to 17 days in a cool and dark place, and the surface of the Fushi is covered with blue-green mold. This initial molding is called Ichiban-kabi (一番黴). This process is repeated, and those that have been processed for Niban-kabi are called Aokarebushi (青枯れ節).

This process is usually repeated four times, and when the Yoban-kabi (四番黴) process is completed, the product is called Hongarebushi (本枯れ節). This process is very effective in reducing the fishy smell and fat content of the Fushi and improving its flavor and color.

The best Katsuobushi is the one that is well-dried, has a tortoiseshell-like color, and a clear metallic sound when tapped. When buying katsuobushi with high-fat content or oxidized fat, the surface color may be white or yellowish-brown, so care should be taken when purchasing katsuobushi.

Kezuribushi made by shaving Hongarebushi is called Katsuobushi-kezuri (鰹節削り). On the other hand, shaved Arabushi is called Katsuo-kezuri (鰹削り). Katsuobushi-kezuri has a milder fragrance than Katsuo-kezuri and is relatively light. This is because the mold softens the smoky smell of Baikan and the fishy smell of fish.

Generally, Arabushi is used mainly in Kansai, while Hongarebushi is preferred in Kanto. The reason for this goes back to the Edo period (1603-1867). At that time, Katsuobushi was transported to Edo by sea from western Japan, including Tosa, Satsuma, and Kishu. However, because mold grew during the voyage, it was dried in the sun and eaten, which added a mild aroma. Since then, mold-dried Katsuobushi has been favored in Edo.

Kezuribushi varies in thickness. Usukezuri (薄削り) is 0.1 mm or less and is used as Hana-katsuo (花かつお) for decoration, and is not suitable for making dashi. Nakakezuri (中削り) is around 0.2 mm thick and is generally used at home because it can be used to make dashi in a short period of time. Atsukezuri (厚削り) is about 0.7 mm thick and should be boiled for about 20 minutes to make dashi. Atsukezuri is rarely used by itself but is often blended with several types of Fushi for commercial use.

Kezuribushi is all about the aroma. To prevent volatilization and oxidation of the aroma, it should be sealed in a plastic bag, with the air inside pushed out, and stored in a refrigerator or freezer. Even though it is dry food, it needs to be handled in the same way as fresh food.

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Revision date: February 21, 2023


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What is Gyosho (fish sauce)?

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Gyosho (fish sauce)

Shiokara (salted fish guts) and Gyosho (fish sauce) are widely produced throughout East Asia and are very similar foods in terms of their ingredients and production methods.

Gyosho is made by preserving raw seafood in salt. It is a fermented food in which the raw materials are broken down into amino acids, mainly by the action of enzymes contained in the raw materials, and the umami is intensified. There are solid and liquid products leached from it.

The production process is not much different from that of salted fish, but salted fish is intended for long-term preservation of protein sources, whereas gyosho is produced for use as a seasoning. It is originally obtained as a byproduct of salted fish, but nowadays, it is produced only for the purpose of obtaining Gyosho.

However, most of the Shoyu produced in Japan is made from cereal grains, and the amount of gyosho produced for local consumption is minimal.

Types of Gyosho

Shottsuru

Shottsuru has long been produced in the Akita area. Sailfin sandfish (Hatahata) is the most well-known fish used, but Sardine and Pacific sand lance are also used. First, the fish’s head, entrails, and tail fins are removed, and the fish is washed in water. Then the fish is drained, and about 10 kg of fish is mixed with about 1,800 ml of rice malt and 1,800 ml of salt, packed in a wooden barrel, covered with a lid, and weighted down. After maturing in a cool, dark place for about three years, the fish is filtered and boiled to make the product.

Ishiru

Ishiru is made in the Okunoto region. There are other names such as Ishiri, Yoshiru, and Yoshiri. The fish used are sardine, round herring, horse-mackerel, etc. The meat is often processed into dried fish, and the surplus heads and entrails are used. About 30% salt is added to this, packed in miso barrels, covered with a sheet, and aged for six months to a year. After that, it is boiled and filtered to make the product.

Ishikawa Prefecture also produces “Ishiri,” which is easily mistaken for “Ishiru,” but it is made from the entrails of the Japanese common squid.

Nam pla (น้ำปลา)

Nam pla is an essential seasoning for Thai cuisine. In Thai, nam means liquid and pla means fish. In the traditional method, small marine fish, starting with sardine, are mixed with 30~40% salt by weight and placed in a large jar for maturing.

After about a year, a long, thin bamboo basket is inserted into the jar and the liquid that has leached out is drawn out and bottled to make the product. Inland, freshwater fish such as Carp and Loach are used. There is also a theory that the origin of Nam pla is to use freshwater fish.

Anchovy sauce

Gyosho, called garum, was widely used in ancient Rome around the 1st century BC. Bluefish such as mackerel would be pickled in salt, stuffed into unglazed jars, and maturing under the sun. The garum that flowed out through a hole drilled in the bottom of the jar was then used as a seasoning. In Italy, garum production stopped around the 16th century.

Anchovy sauce, a similar product made by maturing salted round herring for six months or more, grinding it, and adding spices, is now used as a secret ingredient in spaghetti and other Italian dishes.

Nước mắm

Nước mắm is mainly made from Round herring and Amberstripe scad in Vietnamese Gyosho, and Carp, Loach and Catfish fry are also used around the Mekong Delta. The cleaned fish is placed in a container with 10~15% salt by weight, stirred every morning, and salt is gradually added until it reaches a concentration of about 30%, depending on the progress of maturing. Those aged for one year or more are more delicious. Gyosho from Đảo Phú Quốc is considered the best.

Colatura

Colatura is an Italian Gyosho. It is made from nothing but round herring and salt. The round herring is first removed from the head and entrails and placed in a barrel, alternately layered with salt. Then, a wooden lid is placed on the herring, and weights are placed on top of it for maturing.

After maturing for three to four years, a hole is drilled in the bottom of the barrel and the Colatura is slowly extracted, drop by drop, over time. The slow aging process in the barrels concentrates the flavor of the fish and produces the amber-colored Colatura.

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Revision date: February 20, 2023


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What is Yellow caviar in Japan?

a photo of Yellow caviar
Rainbow trout can also be yellow using a feed that does not contain astaxanthin.

Shinanoyuki-masu (信濃雪鱒) is a cold-water fish classified in the genus Coregonus, which is related to salmon, and was not originally from Japan.

In 1975, eggs were introduced to Nagano Prefecture from former Czechoslovakia, and after 10 years of testing and research at the Nagano Prefectural Fisheries Experiment Station, the prefecture succeeded in establishing the world’s first aquaculture technology.

In 1983, full-scale production began on a private-sector basis, and the fish was named Shinanoyuki-masu (shinano means ‘Nagano prefecture’, yuki means ‘snow’, and masu means ‘trout’), an appropriate nickname for its silvery-white appearance reminiscent of snow.

The neighboring Saku Aquaculture and Fisheries Cooperative Association also sell sturgeon roe under the name Golden caviar after separating the muscle-like roe into pieces and marinating them in salt. However, this is not a Golden caviar, but rather a Yellow caviar.

Generally, River trout, Char, Yamame, and Amago, which grow only in rivers and lakes, do not take red pigments, so their eggs themselves remain yellow. Yellow is also associated with roes but can also come from an albino fish. Rainbow trout is almost always orange, but can also be yellow using a feed that does not contain astaxanthin.

These are what we call Yellow caviar in Japan.

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Revision date: February 18, 2023


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What is Tsukudani?

a photo of Tsukudani
Assorted Tsukudani

Tsukudani (佃煮) is a type of processed food made by simmering small fish caught at the seashore or lakeshore in seasonings. Tsukudani is boiled down in a seasoning solution consisting mainly of soy sauce and sugar, so it can be kept for a long time. In addition to the sterilizing effect of heating, the osmotic pressure created by the salt in the soy sauce reduces the water content in the tissue. This reduces the proliferation of bacteria and thus preserves the fish.

The marine products used to make Tsukudani include small fish such as Spiny goby (Haze), Pacific sand lance (Konago), Half mouth sardine (Shirasu), Crucian carp (Funa), Bitterling (Tanago), and Japanese smelt (Wakasagi); diced Bonito (Katsuo) and Tuna (Maguro); shellfish such as Baby clam (Asari), Orient clam (Hamaguri), and Bloody clam (Akagai); crustaceans such as Shrimp (Ebi) and Mysid (Ami); and seaweeds such as Kombu and Nori. Shio-kombu is also a type of Tsukudani.

For Tsukudani, the freshest ingredients are chosen. If small fish are used that are not fresh, their flesh will fall apart and the seasoning will become cloudy, reducing the value of the product.

When making Tsukudani, the first step is to bring water, soy sauce, sugar, and other seasonings to a boil in an iron cauldron. The ingredients are then placed in the pot and simmered over low heat to allow the liquid to absorb into the tissues of the ingredients. After the simmering process, the Tsukudani is removed from the cauldron and cooled quickly by blowing air through a fan or similar device. The reason for this is that prolonged heat will cause the quality of the product to deteriorate.

The name Tsukudani is said to have originated with fishermen on Tsukuda Island (佃島) during the Edo period (1603-1868), a small island at the mouth of the Sumida River, which flows into Edo Bay. It was named Tsukuda Island after a group of fishermen from the village of Tsukuda in Settsu (摂津), who were invited to settle there when the Edo shogunate was established.

Since Edo’s traditional fishing industry was underdeveloped then, Tokugawa Ieyasu is said to have introduced advanced fishing techniques from the west to supply food for the urban population of Edo.

Tsukuda Island fishermen delivered fish to Edo Castle and the lords. On the other hand, small fish that had no commercial value were seasoned and processed for their use.

Their taste became so well known that they came to be called Tsukuda-ni (ni means simmer) after the name of the land. Tsukudani was a way to make effective use of small fish without discarding them and preserving them.

These Tsukudani were brought back to the country as souvenirs by the samurai on the “Sankinkotai (duty of alternate-year attendance in Edo)”. Eventually, local producers began to follow their example, and it spread throughout the country.

Tsukudani has several variations. Shigure-ni (時雨煮) is made by cooking flaked clams, clams, and other shellfish with soy sauce as well as sansho (Japanese pepper) and ginger. Shigure-hamaguri (時雨蛤) is a specialty of Kuwana, Mie Prefecture. Kanro-ni (甘露煮) is soy sauce with more syrup added and boiled down until there is no more liquid. Ame-ni (飴煮) is made by adding sake and mirin to soy sauce, simmering the ingredients in the seasoning liquid, and then adding more syrup. In the past, Ame-ni was often made with river fish such as crucian carp. In recent years, sugar and syrup have been used in Tsukudani, and the distinction between Kanro-ni and Ame-ni seems to have become ambiguous.

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Revision date: February 17, 2023


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What is the thought behind Toro?

a photo of Toro block
Marbled toro block

Toro salmon, Toro Katsuo, Toro Sawara, Toro saba, Buri toro, Beni toro, and Toro, the original maguro, have all been added to the list, and the number of fish calling themselves Toro, other than maguro, is increasing.

In other words, the word Toro is becoming increasingly generic.

Anyone who has endured the advertising onslaught of the modern era knows that word “toro” always seems to make its way into marketing materials. The word is meant to convey a luxury ingredient, and the “gotta-eat-it” mentality that drives sales.

For example, Toro saba (Saba means ‘mackerel’) is a fatty mackerel. Speaking of fatty mackerel in Japan, the first thing that comes to mind is Norwegian mackerel (Atlantic mackerel). It was once criticized for being too fatty for some unintelligible reason.

In Norway, the amount of mackerel that can be caught in a year is strictly regulated by each fishing boat, so they only catch mackerel when it is fatty and the price is high. Japanese chub mackerel has a peak fat content of 20-25%, while Norwegian mackerel has a peak fat content of 25-30%.

When we looked at the Norwegian Seafood Council’s website to confirm this fact, strangely enough, they do not use a single word Toro mackerel.

The term “fatty” is often used to describe the meat and taste of the fish. This term, of course, implies a high fat content, but the real message we wanted to convey was supposed to be “tasty”. This is because fat contains many flavor compounds. However, literally fatty fish is appreciated and it has become a first-class citizen.

The increase in fatty farmed fish and imported fish such as Northern mackerel may have played a role in this trend, and at the bottom of it all, as with the Toro worship of tuna, there has been a major shift in Japanese eating habits in the postwar period.

In this naming, we cannot help but feel the commercial spirit and skill of the company, which has successfully turned what could be a disadvantage into an advantage by combining changing tastes with the sense of luxury that the word “Toro” possesses.

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Revision date: February 15, 2023


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What is Iromono?

a photo of kanapchi sashimi
The flesh of this fish is beige in color.

At sushi restaurants, sushi toppings are classified as Akami (Aka means ‘red’ and mi means ‘flesh’), Shiromi (Shiro means ‘white’), Hikarimono (Hikari means ‘silver’), and so on. These names are derived from the color of the flesh and the appearance of the fish. However, since there is no clear definition, different sushi chefs have different classifications. For example, if the fish has shiny skin, it is called Hikarimono, and if the skin is removed, it is called Shiromi.

Basically, if the flesh is white, it is called Shiromi. If it is red, it is Akami, but if it is beige, it is called Iromono (Iro means ‘colored’). It may be an obsolete term nowadays, but among older sushi chefs, it makes sense.

The fish that fall into this Iromono category include Hiramasa, Kanpachi, Buri, and Shima-aji. Sawara should also be classified as Iromono, but since Sawara is a newcomer to the Edomae sushi category, it is not classified as Iromono.

It is difficult for the ordinary person to understand what is going on. To add to the confusion, Hiramasa, Kanpachi, Buri, and Shima-aji are called Aomono (Ao means ‘blue’) because they are blue-back fish. This is used primarily as a fishing term.

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Revision date: February 11, 2023


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What is Shiokara?

a photo of Shiokara
Shiokara broadly refers to seafood fermented in their own viscera, salted and seasoned.

Generally, Shiokara (salted fish guts) is a food product made by maturing salted seafood meat and offal. This maturing is a chemical process in which proteins are converted into free amino acids by the digestive action of proteolytic enzymes contained in the offal, creating a rich umami, while the high salt content prevents spoilage. As maturing progresses, the taste becomes less salty and mellower.

Today, shiokara is rarely found in any other food than seafood, but in the past, it was also made from animal meat. As evidence, shiokara made from rabbit and deer meat is mentioned in documents (倭名類聚鈔) dating from 905 to 967.

In the Edo period (1603-1867), eating animal flesh became anathema, and shiokara made from animal flesh gradually declined, leaving only shiokara made from fish and shellfish.

In the Edo period, shiokara was called nashimono (なし物) or natsushimono (なつし物) or nanshimo (なんし物) and included fish and shellfish such as Red seabream (Tai), Horse mackerel (Aji), Pacific cod (Tara), Ark shell (Akagai), Orient clam (Hamaguri), Abalone (Awabi), Prawn (Ebi), and Crab (Kani), as well as birds such as Lark and Quail.

It is said that the term shiokara, which is still used today, took root around the end of the Edo period, and literature from that time describes shiokara being sold as Katsuo, Ami, Ebi, Ika, and others.

These days, shiokara is considered more of a luxury food than a side dish, and many shiokara products cannot be stored without refrigeration because the salt content has been reduced to less than 10% due to low-salt preference. Also, some products are seen with the addition of mirin or rice malt to suppress the salty taste.

And what I must tell you is that there are various delicacies not only in Japan but also in other countries, some of which are characterized by their odd smell and strange appearance, but are also very flavorful.

One of the most typical examples is the shiokara introduced here. It can be said that it is the top 5 stinky food in Japan.

We are fairly sure that Shiokara isn’t the type of dish that will have you coming back for more. But rest assured, Japanese cuisine has so much more to offer.

Types of shiokara in Japan

Ika-no-shiokara (salted squid guts)

Generally, Japanese common squid (Surume-ika) is used, and it is the most in-demand shiokara.

The process is to mix squid liver, commonly called “goro,” with shredded squid meat in a ratio of 1:15 to 20, add 10 to 20% salt, and allow the mixture to stand for about half a month, stirring occasionally, until the meat is broken down by enzymes to produce the characteristic umami, which is then ready to eat. There are three types of shiokara: shiro (shiro means ‘white’)-zukuri, in which the skin is removed; aka (aka means ‘red’)-zukuri, in which the skin is left on; and kuro (kuro means ‘black’)-zukuri, in which squid ink is added.

Tsubu-uni (salted and preserved sea urchin)

a photo of Tsubu-uni
Tsubu-uni is a food product processed from fresh sea urchin to make it last longer.

Tsubu-uni is a specialty of Yamaguchi Prefecture and was invented around 1887, using Bafun uni, Aka uni, and Murasaki uni as ingredients.

The process begins by rinsing the gonads removed from the sea urchin. The product is then sprinkled with about 10% salt, packed in a bottle containing about 20% alcohol, shaken well, and aged for about half a month. The resulting product has a low salt content of about 8%, but can be stored at room temperature for about a year because of its alcohol content of about 9%.

Shuto (salted bonito guts)

Shuto (酒盗) is a shiokara made from bonito entrails. It is a specialty of Kochi Prefecture and is said to have been named by Yamauchi Toyosuke. Fatty bonito that has been frozen for a long time will become discolored, so bonito caught from spring to summer, when it has less fat, is the best material for shuto.

Among the removed internal organs, the pyloric appendage, stomach, and intestines are rinsed and aged with 30% salt. The one made with meat and offal is called “Tataki”, while the one made with only the stomach and intestines is called “Hantou (飯盗)”. It is also called Japanese anchovy and has a distinctive smell.

Konowata (salted sea cucumber guts)

a photo of Konowata
Konowata is salted sea cucumber intestines and is one of the three major delicacies in Japan.

Konowata is a shiokara, the digestive tract of sea cucumbers (海鼠).

When making dried or pickled sea cucumbers, the digestive tract is removed, washed, and soaked in 30% salt. The value of konowata is diminished when it is torn off and the yield is only about 1%, making konowata especially expensive among shiokara. The moment you put it in your mouth, you can smell the mellow aroma of the sea, and it is characterized by its unique sticky texture.

Mefun (salted salmon guts)

Mefun is a shiokara made from Salmon’s kidney.

The removed kidneys are washed in salt water, sprinkled with salt, hardened, then washed in thin salt water to reduce the salt content to about 12% and dried in the shade. The fish is then packed in containers and aged for about six months before being made into a product. The product has a maturing smell peculiar to salted fish.

Uruka (salted ayu guts)

Uruka is the shiokara of ayu fish entrails. There are ko-uruka made with ayu fish ovaries, shiro-uruka made with testes, kiri-uruka made with chopped meat mixed with the entrails, and shibu-uruka made with entrails other than ovaries and testes.

The process is the same for all ingredients: add about 30% salt, remove the leaching liquid, repeat the process of adding more salt, and let the product mature for about one year.

Sukugarasu (salted orange-spotted spinefoot)

In Okinawa, shiokara is called karasu. Kara means spicy and su means salt. Suku refers to the juvenile orange-spotted spinefoot, which are caught around the new moon of the sixth lunar month, when they gather in large schools on coral reefs.

The fish is matured in a dark place with 30% salt added to the fish. The fish is ready to eat within 2 to 3 days after being marinated, but the longer maturing fish is considered tastier. In Okinawa, shiokara of bonito entrails is called Watagarasu, shiokara of squid is called Ichagarasu, and shiokara of sea urchin is called Gashagarasu.

Ganzuke (salted fiddler crab)

A specialty of the Ariake Sea coast of Saga Prefecture, it is mainly made from fiddler crab and is said to have been invented around the 18th century by the lord of the Nabeshima feudal lord at that time.

The process involves removing the abdomen, mashing the fiddler crab with a mortar, adding about 30% salt, chili peppers, and other seasonings, and maturing the mixture for about three months.

Types of shiokara in Southeast Asia

Jeotgal (젓갈)

On the Korean peninsula, shiokara is called jeotgal or jeot, and there are over 40 varieties. Among them, 새우젓 made with small shrimp and 멸치젓 made with half mouth sardine are consumed in large quantities because they are essential for kimchi (김치) production.

The Fujian Han Chinese in Taiwan refer to the shiokara as 鮭 or 鹸鮭. Ingredients include shrimp, small fish, and crab.

Mắm

In Vietnam, shiokara, fish sauce, and narezushi are collectively called mắm, all of which are produced with the main purpose of flavoring dishes.

For example, mắm tôm, a shiokara paste of small shrimp, is made by adding about 20-30% salt to freshly caught shrimp, grinding them in a blender, and then spreading them on winnows and drying them in the sun for 2-3 days before maturing them in a container. It will be ready to eat in about a month, but those that have been around for more than a year are considered tasty.

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Revision date: February 13, 2023


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What are the important points when using ice to kill small fish?

a photo of Korijime
the general practice for small fish is to kill them all together with cold seawater using Korijime.

When it comes to large volumes of small fish like Aji and Iwashi, it’s impossible to use Ikejime for each individual fish. Therefore, the general practice for small fish is to kill them all together with cold seawater using Korijime (“kori” is the Japanese word for “ice”).

Here we will explain the important points of Korijime (氷締め).

The ice is important to maintain freshness. However, this does not mean that more ice is better. The amount of ice used must be adjusted depending on the state of the fish. When Ikejime is performed on live fish and then the fish is put directly on ice, it is killed too early. Also, if ice is only applied to certain parts, only that part will cool, changing the color of the meat. So, rather than directly cooling fish that haven’t yet reached rigor mortis after death, the environment around the fish is cooled.

On the other hand, the fish that have been killed lose their freshness quickly so plenty of ice is applied then in order to prevent changes in the temperature of the fish’s body. Although plenty of ice is necessary, ice is heavy so using so much that it would leave indentations on the fish’s body would be inexcusable. You can tell whether the fisherman is used to handling the fish depending on how much ice is used.

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Revision date: February 4, 2023


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What is Sashimi?

a photo of sashimi
A plate of assorted sashimi

Sashimi (刺身) is made by removing the inedible head, bones, skin, fins, and tail from raw fish, etc., and cutting them into small, easy-to-eat pieces.

It is considered the ultimate washoku dish, but why is such a simple and uncooked dish regarded so highly? In Japan, ingredients that are fresh enough to eat raw are considered more valuable, and sashimi preparation in particular requires substantial labor and technique.

Its preparation begins when the fish is first taken out of the sea. The fishermen perform Ikejime, a technique that shuts off the fish’s neurotransmission in order to preserve freshness and texture while the fish matures.

Each fish has its peak, which is referred to as shun (season), and chefs train for years to develop their ability to determine whether a fish is fresh and its peak. The carefully selected fish is cut into smaller pieces in one stroke with a sashimi boucho (knife), which creates a smooth surface. If the meat is cut with an unsharp knife, it will be crushed and the result will be watery and tasteless.

The chefs pursue pleasing texture, ease of eating, and delicious flavors by varying the thickness of cuts and cutting techniques, depending on the type of seafood they work with.

It is popularly served with soy sauce and condiments such as wasabi, and such garnishes as shiso and shredded daikon radish.

As an aside, sushi restaurants offer a variety of sashimi cuisine. You can order them as assortments, not to mention as single dishes of tuna, sea bream, squid, horse mackerel, or shellfish among others. If the shop has seasonal fish in stock, it might be a good idea to leave your order to the chef.

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Revision date: February 3, 2023


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