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.
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.
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)
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)
Konowata is salted sea cucumber intestines and is one of the three major delicacies in Japan.
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 ayufish 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.
鮭
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.
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.
Sashimi (刺身) is a Japanese dish made by removing the inedible head, bones, skin, fins, and tail from seafood such as fish, squid, octopus, or shellfish, and in some regions from meats like whale, horse, or chicken, and then slicing it into small, easy-to-eat pieces.
Sashimi is sometimes mistaken for sushi without the rice, but the two are considered distinct dishes in Japanese cuisine. Sushi refers to vinegared rice combined with seafood or other toppings, while sashimi focuses solely on the sliced seafood (or other ingredients) itself, served without rice.
It is considered the ultimate washoku dish, but why is such a simple and uncooked dish regarded so highly? Although sashimi is often described as “raw,” it does not always mean completely uncooked. Some varieties are lightly seared on the surface (aburi) or briefly blanched in hot water (yubiki) to enhance flavor, aroma, or texture while keeping the interior mostly raw.
In Japan, ingredients that are fresh enough to eat raw are considered more valuable, and sashimi preparation in particular requires substantial labor and technique. Seafood served as sashimi must meet strict hygiene and safety standards. Depending on the species, it may be flash-frozen at −20°C (−4°F) or lower for a set period to eliminate parasites, as required by food safety guidelines. From the moment it is caught, the fish is handled to minimize bacterial growth, often using the ikejime method to stop nerve activity and preserve texture. It is then transported under strict temperature control, prepared with sterilized knives and cutting boards, and served immediately to maintain peak freshness and flavor. These measures ensure that sashimi is both safe to eat and of the highest possible quality.
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 asshiso 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.
Origin of the Word “Sashimi” There are several theories about the origin of the term sashimi, but one of the most widely accepted and convincing explanations is as follows.
The Japanese have been eating fish since ancient times, but sashimi as a distinct dish became popular after the invention of soy sauce. Soy sauce was developed in the late Muromachi period (14th–16th century) in the Kishu region and later introduced to Edo (present-day Tokyo). At first, it was extremely expensive and only accessible to the wealthy, but over time it became more affordable and spread among the general public. As soy sauce became a common seasoning, sashimi also gained popularity among ordinary people.
In preparing sashimi, the head, tail, skin, and bones are removed, and the flesh is sliced into small, bite-sized pieces. This makes it difficult to tell what kind of fish it is just by looking at the plate. In the past, to identify the fish, chefs would cut off one of its fins and place or “stick” it beside the slices as a garnish. In Japanese, the word sasu (刺す) means “to stab” or “to stick,” and mi (身) means “flesh” or “meat,” so this practice is believed to have given rise to the name sashimi (刺身).
A sushi meal is often completed with clear soup or miso soup. Interestingly, the ingredients in the soup differ depending on the sushi restaurant or the day.
Put all four fingers of your left hand under the bottom of the bowl and place your thumb, gently on the rim. The key is to smell the aroma first. Next hold the rim of the bowl right up to your mouth, and do not make any slurping noises. Then eat between the soup and the ingredients alternately.
Turn the lid over and place it on the right side of the bowl. Do not place the lids on top of each other as this may scratch them. Make sure to drop the water drops from the inside of the lid into the soup.
When asked “Could we serve you a soup bowl now?” at a high-class sushi restaurant, it sometimes is a sign that the Omakase course is about to end. If there are any additional sushi toppings you would like to eat, this is the right time to order. And occasions like having a client dinner imply that your meal has reached the budget you informed in advance.
Sushi made by spreading vinegared rice on a sheet of dried laver and rolling it up with ingredients is called “Makizushi” in Kansai and “Norimaki” in Kanto, and the two are basically the same.
In Kanto, sushi rolls are distinguished by their thickness as “Hosomaki (thin rolls),” “Nakamaki (medium rolls),” or “Futomaki (thick rolls),” but in Kansai, the term “Makizushi” often refers to “thick rolls.
Hosomaki, such as Kanpyomaki (Dried Gourd Shavings Sushi Roll), Tekkomaki (Tuna roll), and Kappamaki (Cucumber roll), generally contain only one type of ingredient, while Futomaki (太巻き) contains multiple ingredients such as kanpyo, tamagoyaki, shiitake mushrooms, and cucumbers.
The size of the nori used differs depending on the thickness of the roll. Hosomaki uses a sheet of nori cut in half, Nakamaki uses one half to one sheet of nori, and Futomaki uses one or more sheets of nori. The basic size of nori is 21 cm in length and 19 cm in width per sheet, and each sheet weighs about 3 g. This size is called “Zenkei”.
The filling and hearty Futomaki satisfies your appetite. It has a slight sweetness, intricate flavors, and pleasant textures. Everything appealing about sushi is packed into a roll of Futomaki.
There are two types of Kaiseki Ryori (懐石料理・会席料理). Both are course meals and have the same reading, but they are expressed in different Chinese characters and the contents are quite different.
In this case, Kiseki (懐石) means a poor meal enough to survive hunger from the anecdote that a Zen priest held a warm stone in his robe to forget the cold and hunger during his training. It consists of soup, rice and three dishes to prepare your stomach before enjoying the strong tea served at the tea ceremony.
As explained earlier, the basis of Kaiseki Ryori at a tea ceremony is one soup and three dishes, but Japanese restaurants, where you are likely to go to eat in person, often have their own arrangements, such as increasing the number of items or changing the order. In a typical menu, oshiki (折敷), wanmono (椀盛), grilled dishes (焼き物), simmered dishes or vinegared dishes (強肴), suimono (吸い物), hasun (八寸), yuto・kouomono(湯桶・香の物), and omokashi・koicha (主菓子・濃茶) are served.
Originally, Kaiseki Ryori was not a sumptuous meal to be eaten with sake, but rather a dish to fill a small stomach before enjoying a more delicious cup of tea.
Kaiseki Ryori (会席料理) is a course meal to enjoy banquest style. In a typical menu, appetizers (前菜), soup (吸い物), sashimi, grilled dishes (焼き物), simmered dishes (煮物), deep-fried dishes (揚げ物), steamed dishes (蒸し物), and vinegared dishes (酢の物) are delivered in order, and finally rice and red miso soup (止め椀), pickles (香の物), and fruits (水菓子) are served. Some restaurants add an aperitif (食前酒).
The most familiar example of Kaiseki Ryori is the food served at hot spring resorts.
Among the fish that belong to the Anguilliformes order such as Eel, Conger eel, and Moray eel, some contain toxic components in their blood serum. This type of serotoxin is called Ichthyohemotoxin and indicates lethal and hemolytic actions. However, this is not the official name of the toxin, and the chemical structure is also not clear.
If a human were to drink a large amount of fresh blood from these fish, they would suffer from symptoms such as diarrhea, constipation, vomiting, cyanosis, arrhythmia, paresthesia, paralysis and respiratory distress, and it would then sometimes result in death. If the blood gets in your eyes, it causes an intense burning sensation, swollen eyelids, and a foreign body sensation that last for days. Sufficient caution must be practiced when preparing these fish, but there is no concern for toxicity if it is cooked. Incidentally, in case of Ichthyohemotoxin, found in eel’s blood, the toxicity completely disappears when cooked for 5 minutes at 60℃, so there are no issues with eating eel Kabayakai.
When it comes to green tea, I’m sure you’ve heard of Gyokuro (玉露) and Matcha (抹茶), but you are likely not familiar with Konacha (粉茶) and Mecha (芽茶). Let’s remedy that by explaining both Konacha and Mecha here.
First and foremost, the three broad tea categories based on the processing method of the young leaves include green tea, oolong tea and black tea, but these are all made of leaves picked from the same trees, and then end up as completely different teas just by changing the processing method. Oolong tea and black tea are made by artificially fermenting the tea leaves as part of the processing. On the other hand, green tea is made without fermentation. The raw material of green tea that is eventually made into Sencha, Gyokuro and Tencha (碾茶), which is the raw material for Matcha among others. Then Konacha, Mecha, etc. are byproducts of the process for making Sencha and Gyokuro.
First of all, Sencha is the foundation of Japanese tea.
Sencha is known for its gentle flavor with a lingering, but subtle sweetness amidst the inherent fresh scent and bitterness. Generally, the color of Sencha is a transparent yellowish gold. Freshly picked tea leaves are immediately steamed, stopping the fermentation process. The steaming process gives each completed, individual tea leaf a deep green color. Tea was originally introduced to the world from China, but Sencha is the only tea with a unique, deep flavor created by Japan. About 80% of the tea produced in Japan is said to be Sencha. The most delicious Sencha comes around from the end of April to May, which is the beginning of the tea season. The appropriate volume of tea when steeping for one person is 2 to 3 grams of tea leaves to 70 milliliters of hot water and the appropriate water temperature is around 70℃ in order to bring out the sweetness and umami.
Next, we’ll describe Gyokuro.
By blocking sunlight and growing in the shade during the sprout timing, the leaves for Gyokuro grow full of theanine, which is an umami component, ending up with tea leaves that have a unique sweetness. It is common to focus only on taste, but the fragrance, described as “enveloping” is also wonderful and should not be discounted. This fragrance is often described by people from outside of Japan as a having a seawater-like scent or being salty. Yame in Fukuoka, Uji in Kyoto and Okabe in Shizuoka prefecture are the three famous production spots for Gyokuro. The appropriate volume of tea when steeping for one person is 2 to 3 grams of tea leaves to 20 to 30 milliliters of hot water and the appropriate water temperature is around 50 to 60℃ in order to bring out the sweetness and umami. This will give you the ultimate cuppa that is the epitome of luxury.
Most of the Agari (cup of tea to finish the meal) served at sushi restaurants is Konacha.
By avoiding the use of a teapot and only preparing the number of teacups needed, directly in the cup, strong tea can be made just by adding the hot water later. Conventionally, steaming is a very important step in making tea, but it isn’t necessary with Konacha. Konacha raw ingredients are mainly made up of the broken tea leaves from the Gyokuro and Sencha manufacturing process.
Brewing konacha results in a dark, deep green color. As the name suggests, it has a lot of powder in it, so the tea leaves in powder form settle in the bottom of the teacup. There for it also carries the benefit of being richer in nutrients than other teas. The sense of transparency is moderate and has a bit of a more somber color. The appropriate amount of water when brewing konacha is one gram of tea leaves to 40 to 60 milliliters of hot water. Konacha is strong, so making it with water that is about 80℃ gives it a mellow flavor. Tea that is made quickly with hotter water gets a moderate bitterness typical of Japanese tea and cleanses the palate.
Also, Japanese people have treasured food since long ago. For example, the leaves of vegetables like daikon radish are sauteed and consumed rather than discarded. As a society they have spent many centuries making efforts to figure out how each part can be made delicious. Mecha is made by collecting the cut-off tips of sprouts and leaves in the process of manufacturing Gyokuro and Sencha. There are many people who think Mecha is tea made just from picking the small buds from tea trees, so don’t make that mistake.
Mecha is a strong green tea that gets a strong scent when brewed. The longer the extraction time is, the stronger the tea, so if the color is too dark it changes the impression it gives and also affects the flavor. That’s why it’s important to pay close attention to extraction time. In general, the volume should be 2 grams for 70 milliliters of hot water–the same as Sencha. When preparing for more people, fewer tea leaves should be used. When brewing, wait patiently for the rounded Mecha leaves to open up. Around 80℃ is the appropriate temperature, but if less bitterness is preferred then it can be made with hot water at 90℃.
In summary, Konacha and Mecha, which are teas used at sushi restaurants, are made from the broken-off parts of the tea leaves carefully selected for Sencha and Gyokuro. They don’t require the steaming step of the tea-making process, so they can be prepared quickly and include the appropriate amount of bitterness for cleansing the palette, making them perfect pairings for nigiri sushi.
When a fish is pulled from the sea, it is put into an extraneous environment with sunlight, temperature and hot human hands that it isn’t used to, so it starts to swim violently with all its might, trying to get away, in a perpetual state of tension. If cooked in this state, blood will still be running through all the cells of the body. There is no sense of transparency in the meat at this point, especially the white meat. The body also hardens. The entire body reeks of blood. In other words, the meat of white fish is full of blood, making it unsuitable for preparing as food.
Fish are placed in a tank with enough water and oxygen, only in numbers so that they do not rub up against each other. A lid is placed on the tank to create a temporary dark space. At this time, the temperature of the water is an ideal, low temperature. This keeps the fish from struggling. After being left for half a day, it will regurgitate anything undigested that was eaten prior to being caught, become acclimated to the dark space and settle down. The bloody tone from struggling fades throughout the body and the fish relaxes.
Creating this state is called “Ikekoshi”.
Ikekoshi methods differ depending on the species of fish, but the idea is to keep this state for only one day at most. When left for two or three days, the fish loses meat, starts to swim around the dark chamber that it has now grown accustomed to, and its body, tail and fins rub up against other fish or the sides of the tank, causing damage. This hurts the meat quality and appearance so it is something the fisherman must look out for.
Crab protein has a high sulfur content. This sulfur can bind with the iron in the can, resulting in ferric sulfide that causes black spots in the meat. Black discoloration of the crab meat significantly mars the appearance and reduces the product value. In order to prevent this, parchment paper with superior water resistance and oil resistance is used to keep the crab meat from coming in contact with the can.
Meanwhile, the trace amounts of magnesium, ammonium and phosphoric acid contained in crab and fish meat sometimes bind to create magnesium ammonium phosphate glassy crystals. This chemical phenomenon is called struvite.
These crystals have no taste or odor and dissolve easily in the stomach so they are not considered to be an issue under the Food Sanitation Act. However, large crystals may hurt the oral cavity so efforts are made to improve production methods to prevent generation of crystals and keep any crystals that do form as small as possible. However, parchment paper does not reduce the struvite phenomenon.
In summary, do you now understand the truth of why crab meat is wrapped in white paper? Of course, nowadays the surfaces of cans are processed in a way that the iron doesn’t start to dissolve, so perhaps the correct theory is that the parchment continues to be used to give a sense of luxury.
There are three elements that make good quality Kuromaguro（Bluefin tuna）.
They are decidedly, color, fragrance and texture.
First of all, color does not simply refer to the color of the cross-section when the fish is cut with a butcher knife.
It refers to how long the fish maintains its “characteristic coloring”. After all, tuna darkens as time passes, eventually turning a burnt-brown color. The true, visual charm of Kuromaguro is the eye-awakening red color that catches your attention when the sushi is placed on a counter or plate. This wonderful coloring is a characteristic of tuna caught through longline fishing or single‐hook fishing. On the other hand, it is said that those caught in round haul nets don’t hold their color and don’t last long. When frozen tuna is thawed, it turns brown within a day. This focus on color is based more on Japanese restaurants that serve sashimi at tables that are located farther away from where the food is being prepared, than on sushi. Incidentally, Mebachi, despite also being tuna, holds its color longer than Kuromaguro does and is suitable for take-out sushi. Minamimaguro is a darker red color than Kuromaguro, but it also loses its color quicker. Kihada maintains its color best.
Next, where does Kuromaguro’s appealing fragrance come from?
The truth is that the source of fish flavor components is still being researched and there are a lot of unknowns. What we do know is that this fragrance is made up of many volatile compounds, but since there are only trace amounts of each one, they are difficult to analyze.
Yet, in the case of expensive Kuromaguro, every measure possible is taken to make sure this fragrance is maintained. Kuromaguro is a migratory fish that gets around by swimming at high speeds in the surface layer of the sea. It needs strong muscles to swim this fast. it also needs to circulate blood throughout its entire body in order to vigorously move those muscles. When a tuna violently struggles to resist and twists its body to avoid being caught, the proteins in its muscles (myosin and myoglobin) rapidly react with oxygen and start to degenerate. This causes Yake and the oxidized odor of tuna. It is important to catch the tuna while causing it as little stress as possible, quickly remove the organs and then use ice to rapidly cool the entire body. If this process is delayed then the pleasant fragrance will transform into an odor. In other words, the scent of Kuromaguro all depends on how it is processed after being caught.
The meat of Kuromaguro that is properly processed emits a unique aroma with a slightly acidic taste when you put it in your mouth. That fragrance lingers for a long time and it combines beautifully with the acetic acid of the sushi rice to go straight to your nose. Then, the moment the fish has disappeared down your throat, the scent of the iron and a subtle acidic taste linger very nicely. This experience is only possible with the exceptional Kuromaguro.
As for the texture, this is determined by the fat distribution of the tuna.
Especially in winter, the Harakami cross-section of Kuromaguro is marbled, much like the Ribulose of Wagyu beef. The melting point for the fat of high-quality tuna is low, and it starts to dissolve even at human skin temperature. This is why sushi chefs who are particular about the sense of unity between shari (sushi rice) and tuna, say, “Shari should be skin temperature.”
There are many chefs who say that the umami of Kuromaguro is in the fat. In the first place, Kuromaguro is one of the fattier fish, and especially between autumn and winter, the Kuromaguro that fed on Surumeika and Sanma has exceptional Harakami. The organs of both Surumeika and Sanma are rich, full-bodied and delicious, even when grilled and eaten by humans. In other words, it is the Surumeika and Sanma that the tuna feeds on that determine the quality of meat. As an example of the meat quality of tuna being affected by what that tuna fed on, Kuromaguro in the Atlantic ocean that has fed on Nishin may exhibit the scent of Nishin when made into sashimi.
However, having a high fat content is not the most important factor. For example, farmed Kuromaguro is fed a high-protein diet so that it will be fatty regardless of the season. Yet, the fat is tougher than that of the wild fish and it’s not something that leaves you wanting a lot more. In comparison, the fat of wild Kuromaguro has a fine texture throughout, immediately melts in your mouth and is digested easily. As sushi chefs know, the fresh fish seems to suction to their hands when making the nigiri sushi. In the same way, it has a smoothness that seems to suction to your tongue when you put it in your mouth. Once you’ve swallowed, it leaves you craving more.
Both conveyor belt sushi and premium sushi have versions of sushi made with raw sweet shrimp or botan shrimp. However, in Edomae Sushi, boiled shrimp is always used. The use of raw shrimp in sushi started in the Kansai region. Moreover, in the Kansai region, there are many restaurants that make sushi with live Kurumaebi known as “Odori or Kassha”. However, this way of eating may be declining nationwide. It is probably because there is increased texture when boiled, so it tastes better.
Going back to Odori, “Odori” means “dance” in Japanese and it is said that this name came from the fact that shrimp twitches on the sushi rice and looks like it is dancing. If you look up the roots, it seems that this method of serving started at a sushi restaurant in Kyoto City in the early Showa period. It spread throughout the Kansai region, but although Odori may look easy to make, the method is actually quite elaborate.
Let’s introduce the common recipe here. First wash the live Kurumaebi with fresh water and start by bending the head with your hand while detaching it from the body, then peel off the shell. Next, peel the skin off the abdomen and cut the abdomen open vertically. Fresh shrimp is difficult to peel, so it is important to do it very carefully. Next remove the veins from the back and sprinkle on just a bit of mirin and vinegar, then lightly rinse off with ice water. After that, parboil just the tail in boiling, salted water to make it look attractive.
Then make the sushi with the open side facing up. The direction is important because it is easier to tell that the shrimp is dancing when it is arranged this way. To finish, sprinkle lemon juice over the shrimp meat. This stimulates movement of the body.
Now let’s discuss how a customer eats Odori. It goes without saying that since the shrimp is still alive, the moment you dip the topping in the soy sauce, the shrimp twitches in its death throes, convulsing violently. Apparently the customers are greatly pleased to see this. We don’t recommend the faint of heart to order this dish.
Incidentally, eating only the shrimp in this way is called “Odorigui”. In China there is a dish in which living shrimp is soaked in Shaoxing rice wine or fermented alcohol, made drunk, and then eaten once it has settled down. These sorts of methods may be considered cruel in some western countries.
There are three elements that make good quality Kuromaguro（Bluefin tuna）.
First of all, color does not simply refer to the color of the cross-section when the fish is cut with a butcher knife.