Sushi Ingredients | Sushiblog

What is sushi or sashimi grade fish?

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

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

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

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

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

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

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

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

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

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

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

The situation in Japan is a bit different.

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

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

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

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

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

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Revision date: March 1, 2024

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What is Moshio?

a photo of moshio — Natural salt with a pleasant taste

The “Mo” of “Moshio (藻塩)” means “seaweed (海藻)” and “shio” means “salt (塩).” The only ingredient in Moshio is Hondawara, a type of seawater and seaweed. It is also called Mojio.

The way it is made is extremely primitive. First, Hondawara (Gulfweed), etc. is soaked in seawater then wrung out and dried multiple times over 2 to 3 days. This creates a brown-colored seawater infused with the umami and color of Hondawara. In the end, Hondawara is dried and grilled, then the charcoal ash is mixed with the seawater infused with the umami and color. This is left for a day, where the ash naturally sinks to the bottom, completing the dark-brown seawater. Moshio is made by boiling down this seawater. This is said to be the origin of salt-making far longer ago than the manufacturing method of using salt farms.

According to a sushi chef at a Michelin Star restaurant, there are two types of Shari and each will either bring out the best of either Akami or the Shiromi. When pursuing ideal Shari to go well with a variety of toppings, this chef happened to come across Moshio. This led to a lot of trial and error, and eventually he came up with a fully universal type of Shari. Perhaps switching to Moshio is a good idea.

It is characteristic in that there is no sharp spiciness and it has a very mellow flavor, so it brings out the taste of the elements of seafood, etc. The color is a light beige and the salt can be called a concentration of umami made from nothing but seawater and seaweed.

What is Geso?

Geso is not the name of a fish or shellfish.

Geso refers to the 10 arms/tentacles of a squid.

A photo of Geta — The appearance of Geta (wooden clogs)

The reason squid arms came to be called “Geso” is that the shoes that are removed before entering the indoors in Japan are referred to as “Gesoku”. The name comes from a time when restaurants used to hold onto their customers geta (wooden clogs) and the cloak would tie them with a string in 10-pair units.

Geso can be lightly boiled or grilled. For large squid, a butcher knife is inserted at the tip of the arm to peel off the skin membrane, and then the tips of the arms are cut off so the sizes match. When Nitsume or other sauce is applied and it is made into Nigiri, it has an excellent springy texture and scent of the sea. It is also used as Tsumami when drinking alcohol. In my personal opinion, the Geso child of Sumiika is nice and soft and worlds above any others.

This is one of the sushi terms that even most of the general public in Japan knows well.

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Revision date: July 2, 2024

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Do you know why canned crab is wrapped in paper inside the can?

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.

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Revision date: August 1 2022

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What is Odori?

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.

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Revision date: June 6, 2022

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The answer to the question, “Can I eat sushi leftovers the next day?”

Nigiri sushi is generally made with raw seafood. It can be said that the seafood starts to go bad as soon as it is put on warm rice. Of course, at the stage of preparation, there are procedures being taken to reduce the causative micro-organisms of food poisoning. Out of all food that is commonly eaten raw, sushi is considered to have the least micro-organisms that cause food poisoning.

For example, Vibrio parahaemolyticus, a typically known bacteria that causes food poisoning, attaches to seafood, and if the conditions, such as temperature, are just right, it proliferates at double the speed of other food poisoning bacteria. When you are eating at a sushi restaurant, bacteria growth is being suppressed. However, if you take sushi home to eat it, depending on conditions bacteria could proliferate.

This is why as a basic rule, you cannot take sushi home from a sushi restaurant.

So then, what is the difference between sushi sold at the grocery store and prepared at sushi restaurants?

There are obvious differences between sushi made by sushi chefs and take-out sushi, as explained below.

Take-out sushi is lined up at the store, selected by the customer, then eaten at home, which takes time. Therefore, a higher amount of salt seasoning is used compared to Nigiri sushi restaurants, in order to delay the degradation in quality. Sushi made by sushi chefs at restaurants has a salt content of about 1% in the sushi rice, while that of take-out sushi has about a 2% content.

Next, with a pH of around 4.5%, it is difficult for bacteria such as Salmonella, Staphylococcus aureus, E. coli bacterium bacteria and Vibrio parahaemolyticus to proliferate, and there are experimental results that show they die out. In an experiment that measured the pH of sushi rice in take-out sushi, it was usually measured at 6%. Nigiri sushi made at a restaurant is often around 6.2%, so this acidity is put to good use in the sushi rice and could be delaying degradation.

Furthermore, although it may not be a pleasant topic of discussion, preventing spoiling and deterioration in food caused by micro-organism is done by adding preservatives to improve the shelf life. For example, classic preservatives such as benzoic acid, Sorbic acid and PH adjusters are used all over the world. There is an obligation to list these on the product label when used.

Now let’s get into the main topic.

This all being said, sometimes when you buy take-out, there are leftovers. There is no question that it is better to promptly discard them. But you may think that you can just eat it the next day, right?

You can. And it will taste the same as when you bought it.

First of all, there is something important to remember; not all toppings are equal in take-out. Unfortunately, things that require freshness like shellfish, squid, mackerel and sardines, cannot be saved. These must be consumed on the day they are bought.

Next, let’s go over how to eat your day-after sushi so that it still tastes good.

The toppings this method works for are tuna, salmon, white fish and steamed shrimp. However, the only white fish it works for are benthic fish such as flounder. As long as the meat is still transparent the next day, it’s safe. For Hamachi, which always has more than 20% body fat, which oxidizes, so avoid keeping it to the next day. Raw shrimp is out too. Steamed shrimp becomes more delicious when quickly put into sushi vinegar for storage.

The method is simple!

First, remove the Nigiri sushi topping from the rice. Next, wash that topping with running water for a few seconds and then dry well with a paper towel. Make sure you are quick in all of these steps. Finally, wrap in plastic wrap and store in the refrigerator.

Next, use a wet paper towel to wrap the sushi rice. Wrap this set in plastic and put it in the vegetable drawer if possible. If you don’t have a vegetable drawer than the normal refrigerator compartment is fine.

The next day, when you are ready to eat, heat the sushi rice in the microwave at 1000W for 10 seconds. The point is just to warm it up a little. Next, just take the topping from the refrigerator and place it on the rice. You can add some wasabi if necessary.

Incidentally, if you use this method for take-out sushi, even when consuming it on the same day, it will taste even better than just eating it right away.

The practice of sushi chefs is to put somewhat cold sushi toppings (16~19℃) or room-temperature toppings (20~23℃) on top of sushi rice that is the same temperature of the human body (37℃). We are trying to imitate this method. If you are consuming on the same day, any topping can be removed from the rice and prepared like this.

But please do not wait any longer than the next day to eat any leftovers.

Do not bend this rule. Let me warn you that the symptoms of food poisoning from shellfish and silver-backed fish are horrible. It should also go without saying that if the sushi rice has already dried out, there is no bringing it back, even with this method. Once you’ve reached that point, you just have to throw it away. Naturally, you cannot eat smelly sushi toppings.

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Revision date: April 1, 2022

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What is used as a substitute for the expensive Mongou ika?

No people in the world love squid more than the Japanese. Squid ranks third in import volume behind shrimp and tuna. Squid is brought to Japan from the oceans all over the world. There are between 400 and 500 species of wild squid on Earth. Some, like the pygmy cuttlefish, are tinier than 3 millimeters while the giant squid is over 10 meters.

There are about 100 species of squid that live in the waters surrounding Japan. Surume ika (Japanese common squid) makes up the highest volume of domestic-caught squid. It is used as a Yari ika or Surume ika topping in eastern Japan, but Surume ika isn’t used very often in western Japan. At sushi restaurants, squid like Sumi ika (Golden cuttlefish), Aori ika (Bigfin reef squid), Kensaki ika (Swordtip squid) and Mongou ika (Ocellated cuttlefish) go for high prices, but they are all caught in smaller quantities and therefore only available to high-end sushi restaurants that can procure them fresh.

There are some conveyor belt sushi restaurants that list Mongou ika (モンゴウイカ又はカミナリイカ) on the menu, but actually serve European common cuttlefish. It is produced in the waters off the coast of West Africa. Even some sushi restaurants do this. This is actually still too pricey for conveyor belt sushi though. What is generally used at conveyor belt sushi is Flying squid, which goes for only 1/10 the price of the European common cuttlefish and reaches 60 cm in length. Jumbo flying squid is also often used. The Jumbo flying squid is more than twice as long as the Flying squid and exceeds 1 meter in length. The Jumbo flying squid is mainly imported from places on the other side of the world such as Chile and Mexico. The thickness of the meat is similar to Mongou ika. However, a big drawback is that the Jumbo flying squid lacks the sweetness peculiar to squid. Therefore, it is soaked in water that has been artificially sweetened. This alters the dried out sensation to a plump, moist sensation, making the customer believe it is Mongou ika.

The squid must have a certain thickness in order to masquerade as Mongou ika. Rhomboid squid, which has a torso length of 80 cm is also disguised as Mongou ika. Rhomboid squid is found in the warm waters of the world and is even caught in relatively high volume in Japan. Large squid have a low price cost, so it’s good for the shops to make a profit. Furthermore, the sweetness is brought out more when frozen first than by serving it fresh. That means it can be used as Mongou ika without any need for the artificial sweeteners used in Flying squid and Jumbo flying squid.

The fact is that there are many substitute products for Mongou ika. But even so, it doesn’t change the fact that using ingredients disguised as others is an unacceptable practice.

Types of substitutes for the Mongou ika

European common cuttlefish: Sepia officinalis (Linnaeus, 1758)

European common cuttlefish (ヨーロッパコウイカ) is found from the Atlantic coast of France to the Mediterranean and west coast of Africa. It is often caught in the waters around Morocco. Its body length is around 30 cm. When it first arrived on the Japanese market, it was called Mongouika, hence the name.

The scientific name sepia means black pigment and officinalis means medicinal, indicating that this is a material for Chinese herbal medicine. At processing plants in Thailand and China, the fish is made into fillets for sashimi, and then vacuum-packed and sent to Japan.

Flying squid: Ommastrephes bartramii (Lesueur, 1821)

Flying squid (アカイカ) is distributed in the North Pacific, South Pacific, and Atlantic Oceans. Its body length exceeds 40 cm, and it can weigh more than 4 kg. It is similar in appearance to the Surumeika, but has a darker, blackish back. It is used as a substitute for Surumeika for processing such as delicacies.

Jumbo flying squid: Dosidicus gigas (Orbigny, 1835)

Jumbo flying squid (アメリカオオアカイカ) is found only off the Pacific coast of the United States, Chile and Peru in South America. They are over 80 cm in length, weigh around 10 kg, and have as many as 100 to 200 suckers. In Peru, they are called Pota. Japanese fishing vessels used to catch flying squid mainly in the North Pacific, but their catch has drastically decreased due to the ban on drift net fishing.

Japanese vessels have switched to fishing for Jumbo flying squid, a member of the flying squid family, in the waters off Peru and other areas. Fishing for Jumbo flying squid in Peruvian waters continues from spring to fall.

Since the drifting net fishing of flying squid has been banned, it is the most promising resource as a raw material for processing. However, the larger ones store ammonia in their muscles, so de-ammonia treatment is required when processing them.

Rhomboid squid: Thysanoteuthis rhombus Troschel, 1857

Rhomboid squid (ソデイカ) is widely distributed in the warm waters of the Pacific and Atlantic Oceans. The body length is 70 cm. Its fins are diamond-shaped and the same length as its body. Because they do not form large schools and live scattered, they have been a difficult resource to exploit.

After a new fishing method was developed in the Tajima region of Hyogo Prefecture in the 1960s, the fishery began in earnest. Because of its reasonable price, it is often used in restaurants such as conveyor belt sushi restaurants. Also called Diamond squid or Diamondback squid.

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Revision date: March 24, 2023

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The general rule is to only eat oysters in months that contain the letter “R”.

In other words, avoid them from May to August.

It’s won’t hurt you to eat Magaki (Japanese oyster), which has its spawning season in the summer, but in the months with no R in the name, the glycogen concentration is low, so you can’t get the full-bodied texture that you get in winter. In addition, almost all amino acids such as glutamic acid, glycine, alanine, arginine, which are important components for delicious flavor, are known to accumulate from winter through spring, and conversely, they decrease in the summer, which is the spawning season. You cannot expect the same deliciousness from oysters in summer as you can from months that contain the letter R.

Furthermore, the oyster takes in large amounts of seawater and filters out the plankton for its food. Therefore, in warm seasons it fills up on large volumes of the toxic plankton that proliferates in the sea. Eating toxic plankton can make the oyster toxic and toxified oysters can cause food poisoning when consumed by humans. In addition, in the warmer months, the oyster loses its freshness faster after being harvested, increasing the likelihood of getting a bad one and risk food poisoning. Therefore, it’s best to not go out of your way to eat oysters in summer.

On the other hand, one certain oyster is actually in season in summer.

Iawagaki (Rock oyster) is known as the summer oyster. This type is close to the Magaki, and it lives attached to reefs at depths of 2 to 20 m, deeper than the intertidal zone and facing the open sea. A large Iwagaki has a shell length of 10 cm, a shell height of 20 cm or more and weighs more than 1 kg. However, the edible part is small compared to the size of the shell. It is an oviparous hermaphrodite. Growth is slow at a rate of around 5 cm in one year, around 7 cm in two years. It takes three to four years to reach 10 cm or more and grow big enough to harvest.

The glycogen volume in Iwagaki is high from March to July, peaking around May, and it then decreases from September to October. The main production areas are the Sea of Japan on the coasts of Akita, Yamagata, Niigata, and Tottori. Many of the Iwagaki in circulation are harvested from the wild, unlike Magaki, which is almost all farmed.

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Revision date: February 1, 2022

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Is the combination of Chablis wine and Japanese oysters match made in heaven?

White wine is generally thought to go well with fresh seafood.

For example, every Frenchman knows that Chablis wine and Belon oysters go together like peanut butter and jelly. The soil of Chablis is made of the stratum that dates back to the Kimmeridgian age and a unique characteristic is that the soil is rich in fossils of small oysters and shellfish. That is why oysters and Chablis wine are said to be the perfect pairing. However, surely there are Japanese people who sense the fishy odor when having Chablis wine and Japanese oysters (Magaki) together. Therefore, some people say that sake is definitely preferred over wine.

The reason for this is that the types of oysters in France and Japan differ.

Famous for its Belon brand name, the oyster native to Europe has a flat, rounded shell. It belongs to the genus Ostrea. To be honest, Belon oysters aren’t sweet and don’t have a distinguished flavor compared to Japanese oysters, and the salty fragrance of the sea is dulled, so it can seem less flavorful.

Meanwhile, the Japanese oyster is elongated and shaped like a raindrop. It is characterized by a smell like it swallowed the whole ocean. This is the main species farmed in Japan. It belongs to the genus Crassostrea. The taste is as if the umami components of the sea have all been concentrated together in one little shell.

Going back to pairing Chablis wine with oysters, it’s common sense in the world of flavors that items with basically similar components pair well together.

The issue lies in how wine is made. Chablis wine contains lactic acid because it is made through forced mal-lactic fermentation. Because it contains this lactic acid, it is partially fighting against the Belon oyster, which has a high glycogen content. In addition, lactic acid is called “warm organic acid”, and it has the property of becoming delicious at warm temperatures. Oysters are eaten cold, so they aren’t good for taking advantage of “warm organic acids”.

Therefore, it can be said that rather than Chablis wine, it goes well with cold organic acid white wine that is delicious when cooled to 7 or 8 degrees, for example, German Franken wine.

So then, what should be done when pairing oysters with Chablis wine?!

If you insist on pairing oysters with Chablis wine, go all out and add squeezed lemon so the citric acid will work to mask the lactic acid and succinic acid, in turn making the wine taste good even when cold. Citric acid is a “cold organic acid” that becomes delicious when cooled, and oysters rich in glycogen go well with “cold organic acid”. Cold acid-based white wine is abundant in the refreshing “cold organic acids” known as malic acid and tartaric acid. Oysters lack this cold organic acid (malic acid and tartaric acid), so adding the citric acid of lemon creates an exquisite harmony.

However, in France there was a time when a disease spread that caused the death of the Belon oyster, nearly rendering it extinct. Therefore, since the Japanese oyster has been transplanted so many times, it is said that nowadays, at least 90% are Japanese oysters hybrids of Japanese oysters.

That means the question remains among Japanese as to whether the combination of Chablis wine and oysters really is a match made in heaven or not. Personally, we’ve never heard of oysters served without lemon, so the fishy smell really isn’t an issue at all in the end.

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Revision date: January 6, 2022

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What is used as a substitute for Madako (Octopus)?

Among the many sushi toppings, Pacific bluefin tuna, and actually the Madai (Red sea bream) as well, are toppings that are difficult for an amateur to tell whether it is farmed or wild. However, there is no need to worry about that when it comes to Tako (Octopus). There are no octopus farms to be found in the world, so it is a 100% wild topping.

In Japan, domestic production isn’t enough to satisfy the appetite of Japanese who like Tako, so the majority relies on imports. Imports from Africa account for 80% and the remainder is imported from China, Southeast Asia, Mexico, Spain and other places in the world.

Most of the African imports are produced by nations on the northwestern coast, with the highest number coming from Mauritania. Until 2003 the highest volume came from Morocco for many years. However, due to continued mass catches to sell to Japan, Tako numbers dropped drastically, leading to the Moroccan government panicking and outlawing fishing. For some reason, Japanese people have grown to love Tako and now consume nearly half of the Tako caught throughout the world.

There are over 200 types of Tako in the world with approximately 60 types inhabiting the seas near Japan. Among these, the Japanese mainly only eat Madako, Mizudako and Iidako. Even among these, Madako makes up at least 80% of consumption.

Most of the Tako found at conveyor belt sushi is African Madako (Madako from Africa). African produced Tako is boiled on-site before being imported frozen. The cost is 20 cents or less per topping.

Amateurs can’t tell the difference between domestic Tako or African imports. However, there is one aspect that even an amateur can use to distinguish between the two. There is one condition for this to work, and that is that at least one of the suckers is in-tact. The suckers are scraped off for most toppings, but in cases where they are sliced by the restaurant, there are often suckers remaining. If the sucker is pure white, it is almost definitely from Africa. Meanwhile, domestic Tako suckers maintain a faint red color in the suckers, even when boiled. The reason the suckers turn white seems to be an effect of the food preservatives added during processing, but this has not been confirmed.

There happens to be a substitute for Madako as well.

One of these is the Iwadako from Vietnam, which grows as large as the height of an adult human. It is imported in frozen slices that can be used as raw Tako as soon as it thaws. The cost of this topping is 20 cents or less per piece. This ends up disguised as Hokkaido Tako.

There are also domestic substitutes. Yanagidako (Chestnut octopus) is mainly caught in the Pacific Ocean, from Chiba prefecture northward. The flavor is lighter than Madako, but it is also softer than Madako, so some people actually consider it to be better than Madako. If it is boiled and made into sushi, an amateur can’t distinguish between it and Madako. The legs are thin so they just need to be cut at an extreme angle in order to make the topping appear bigger. The cost of this topping is 15 cents or less per piece. It is also used as Mizudako because it is watery when eaten raw.

As you can see, there are also many substitute toppings for Madako.

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Revision date: December 21, 2021

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What is Toro Katsuo (Torogatsuo)?

Toro is an absolute at sushi restaurants and it’s only natural to aspire to such a position. That’s why there are so many sushi dish names that start with “Toro”. The most laissez-faire of these is Toro salmon. In this case the definition of Toro is ignored in an attempt to promote sales. Just as bad is Toro katsuo (pronounced “Toro-gatsuo” in Japanese).

Katsuo is born in the warm southern seas. When it reaches about two years old it migrates north in pursuit of Iwashi and other small fish. There are two routes taken by the Katsuo that come to the seas around Japan. One of the routes rides the Kuroshio Current (a warm current) from around the Philippines, passing by Taiwan and the Ryukyus Islands, arriving in southern Kyushu. From there the Katsuo rarely heads toward the Sea of Japan and instead the majority moves northward on the Pacific Ocean side. The Katsuo migration schedule may shift depending on the temperature of the seawater and how the schools of Iwashi and Aji (which the Katsuo feeds on) are migrating that year. The first group appears around Ishigaki Island about January, then in the seas off the shores of Kyushu and Shikoku between February and March. It then moves to the seas off of the Izu and Boso peninsulas between April and June. It reaches the open seas off the southern coast of Sanriku and Hokkaido between July and September.

Another route follows the Ogasawara ocean current from below the equator in the seas off the shore of Papua New Guinea and the seas around Micronesia to the Ogasawara Islands, along the Seven Islands of Izu and approaching the open seas off the Boso Peninsula. The route then goes northward to join with the routes mentioned above.

It’s the Modori-gatsuo that begins reverse migration toward the south at the beginning of autumn when the water temperatures start to drop. Katsuo has a strong appetite before returning south in preparation for the long trip. Unlike the light-flavored Hatsu-gatsuo, the Modori-gatsuo has plenty of fat and its body fattens up quite a bit. The main fishing locations for Modori-gatsuo are in the northern Pacific, such as the waters off the shore of Sanriku. This is the season when it is truly worthy of the name Toro katsuo when served raw, and nothing else should be called by the same name.

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Revision date: December 1, 2021

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What is Meki? Substitute for Kuruma ebi?

Japan leads the world in shrimp consumption by far. Most of the shrimp is imported, but it is a little known fact that shrimp is called “Meki” among importers and sushi restaurants in Japan. It is said to be a remnant from a time when much of the imported shrimp came from Mexico (pronounced “Mekishiko” in Japanese).

Shrimp can be caught within 45 degrees north or south of the equator. The caught shrimp is quick-frozen on site and then sent to Japan. Mexico was early in advanced refrigeration technology so when it became impossible to catch shrimp in the seas around Japan in the 1970s, a large volume of shrimp was already being imported from Mexico. It was around that time that importers shortened the phrase “Shrimp imported from Mexico” to “Meki”.

After that the major source of shrimp imports switched to Taiwan, which started shrimp aquaculture, and it is now also imported from Thailand, Indonesia and China. The name “Meki” stuck in the industry, despite the fact that shrimp is now mainly imported from other places in Asia.

Imported shrimp is categorized by body color tones, either brown, pink or white. The color is combined with the place of origin or country name and that is what each type of fish is called at the distribution stage. For example, they may be called Mexico brown or Guiana pink.

Well-known brown-toned shrimp include Ushi ebi (Black tiger shrimp) and Mexico brown (Yellowleg shrimp). Pink-toned types include Guiana pink (Pink spotted shrimp) and Nigeria pink ebi (Southern pink shrimp). White-toned shrimp include Taisho ebi (Fleshly prawn), Banana ebi (Banana Prawn) , Eedeavour ebi (Eedeavour prawn) and Vannamei ebi (Whiteleg shrimp). There are many sushi restaurants that use pink and brown-toned sushi that turn into a nice red color when boiled. While the meat of white-toned shrimp is soft, it turns a whitish color when boiled and doesn’t look very appetizing. However, due to the splendid, large tail, it is perfect for tempura or fried prawns.

Next, We will touch on the characteristics of shrimp that is typically imported to Japan. All these types are actually related to the Kuruma prawn, which is representative of premium shrimp and a familiar ingredient of sushi. In other words, these imports are alternatives to make up for the shrimp consumption in Japan that can’t be covered by the Kuruma prawn. Normally the head is removed, it is frozen, packed in large lots, and then embarks on the distribution channel in Japan.

There are about 27 species of kuruma prawns (Penaeus japonicus Spence Bate, 1888). The following is a list.

Crystal shrimp: Farfantepenaeus brevirostris (Kingsley, 1878)

Witch Shrimp: Farfantepenaeus Burukovsky, 1972

Northern pink shrimp: Farfantepenaeus duorarum (Burkenroad, 1939)

Indian white prawn (Shonanebi): Fenneropenaeus indicus (H.Milne Edwards, 1837)

Caramote Prawn: Penaeus kerathurus (Forskål, 1775)

Western king prawn (Futomizoebi): Penaeus latisulcatus Kishinouye, 1896

Redspot King Prawn: Penaeus longistylus Kubo, 1943

Aloha Prawn (Terao-kurumaebi): Penaeus marginatus J.W.Randall, 1840

Western White Shrimp (Tenjiku-kurumaebi): Penaeus occidentalis Streets, 1871

San Paulo Shrimp: Penaeus (Melicertus) paulensis Pérez Farfante, 1967

Redtail Prawn (Akaoebi): Penaeus penicillatus Alcock, 1905

Southern White Shrimp: Penaeus schmitti Burkenroad, 1936

Green Tiger Prawn (Kumaebi): Penaeus semisulcatus De Haan, 1844

Northern White shrimp: Penaeus setiferus (Linnaeus, 1767)

－: Penaeus silasi Muthu & Motoh, 1979

Blue Shrimp: Penaeus stylirostris Stimpson, 1874

Southern Brown Shrimp: Penaeus subtilis Pérez Farfante, 1967

The following is a list of those commonly used in sushi restaurants and Japanese restaurants in Japan.

Guiana pink (Redspotted shrimp, Spotted pink shrimp /Farfantepenaeus brasiliensis (Latreille, 1817))

For more information, go here.

Taisho ebi (Fleshly prawn /Fenneropenaeus chinensis (Osbeck, 1765))

It is found from the Indian Ocean to the Pacific Ocean, the Malay Archipelago and Australia. The species is of considerable commercial importance in the Yellow Sea, East China Sea and Korean Bight, where it is trawled. It is sold in Korea, China, Japan and Hong Kong. This is a large shrimp that reaches up to 25 cm in body length. The appearance is similar to the Kuruma ebi, but without any special pattern. The edge of the abdomen is a dark brown color. There are 28 known species related to the Kuruma ebi. In the Toyosu market, those with a striped pattern are Kuruma ebi, and those without are Taisho ebi. In Japanese it’s been dubbed “Korai ebi” is due to the fact that it is often caught in the waters off the west coast of the Korean peninsula. The soft meat has a sweetness that makes this shrimp delicious. The number of wild Taisho ebi has decreased drastically in recent years. The coloring is lighter than Kuruma prawn and Black tiger shrimp, but darker than other white-toned shrimp. This type has a long history compared to other imported frozen shrimp and such high volumes were imported from China that it was called Chinese Taisho. It accounted for the majority of the market share until farmed Black tiger shrimp started to appear on the market.

Banana ebi (Banana Prawn /Penaeus merguiensis De Man, 1888)

It found around the northern coast of Australia from the New South Wales-Queensland border to Shark Bay in Western Australia, it is mainly caught by trawlers between Exemouth Gulf, Western Australia and Brisbane, with the bulk of the catch coming from the Gulf of Carpentaria. It weighs between 18 to 30 g per shrimp and is colored like a banana. The meat is soft and has a sweetness. Sometimes it is also sold as Taisho ebi. The body is thinner and slenderer than the Black tiger shrimp. It is available year round with peak supply in April.

Mexico brown (Yellowleg shrimp, Brown shrimp /Farfantepenaeus californiensis (Holmes, 1900))

For more information, go here.

Vannamei ebi (Whiteleg shrimp, Pacific white shrimp/Litopenaeus vannamei (Boone, 1931))

For more information, go here.

Ushi ebi (Black tiger shrimp, Giant tiger prawn/Penaeus monodon Fabricius, 1798)

For more information, go here.

Australia tiger (Brown tiger prawn /Penaeus esculentus Haswell, 1879)

The Australian tiger (Brown tiger prawn) is endemic to Australia and is found at depths of 15~20 meters along the coast except in the southern part of the country. Its main locality is the Gulf of Carpentaria on the northern coast of Australia. It reaches 25 cm in length but is generally 15~20 cm long.

Because of its beautiful red legs and reddish-brown stripes, this shrimp is mainly imported to Japan with its head on. In addition to its shape and size reminiscent of Kuruma ebi, it is a high-end variety that is not so tough, sweet, and has a good taste and coloration and is used in grilled dishes and tempura.

Nigeria pink ebi (Southern pink shrimp, Candied shrimp/Farfantepenaeus notialis (Pérez Farfante, 1967))

Nigeria pink ebi (Southern pink shrimp) is found from Mauritania to Angola at depths of 20~100m. It is also found in the western Atlantic Ocean from the Caribbean coast to southern Brazil.

It inhabits bottom mud or sandy mud, and sandy patches among rocks in marine environments. Juveniles are found in estuarine environments. Also inhabits lagoons. It is often used for sushi because of the soft meat, good flavor, and nice coloring. This is one of the highest grades of imported shrimp.

Mexico ebi (Northern brown shrimp, Brown shrimp /Farfantepenaeus aztecus (Ives, 1891))

Mexico ebi (Northern white shrimp) is distributed from the Gulf of Mexico to depths of up to 30 meters along the eastern coast of North America. Juvenile shrimp grows in estuaries. It is the most important species in the Gulf of Mexico, with an average annual catch of nearly 30,000 tons. On the other hand, Southern white shrimp is distributed in shallow waters from the Caribbean Sea to southern Brazil. It is almost indistinguishable from this species in appearance, but the male and female reproductive organs differ in shape.

Maximum standard length: 22 cm. It lives in bottom mud or peat, often with sand, clay, or broken shells. Adults inhabit the marine environment. Juveniles inhabit the estuarine and marine environments. There are 13 types of brown-toned Kuruma prawn in the world and the names get confusing.

Also called Golden Shrimp, Red Shrimp, Redtail Shrimp.

King ebi (Eastern king prawn /Penaeus plebejus Hess, 1865)

Adults are found in marine environments while juveniles are found in estuarine environments. It is found over sandy bottoms at depths of 2-350 m or deeper.

Finally, the shrimp introduced in this section is consumed not only in Japan but all over the world. Judging by the images on social media, takeout sushi and the frozen shrimp sold at Costco are made from one of the types of shrimp described here. If you’re going to learn about sushi, it’s important to learn the types of shrimp used in sushi.

India ebi (Indian prawn/Madagascar white prawn/Fenneropenaeus indicus (H.Milne Edwards, 1837))

India ebi (Indian prawn) is widely distributed from the Philippines through Southeast Asia to the western Indian Ocean. It is especially important in the waters from the Indian coast to the western Indian Ocean.

It is a White species of Kuruma ebi and is similar in appearance to the Banana Prawn. Once the head is removed, it is difficult to distinguish between the two species. In Southeast Asian markets, both species are sold together.

Those distributed in East African waters have brownish bodies and reddish legs. It has a rich flavor and aroma and is very tasty. It is suitable for frying and tempura.

Also called Indian white prawn, Tugela prawn , White prawn.

Endeavour ebi (Endeavour prawn/ Metapenaeus endeavouri (Schmitt, 1926))

Endeavour ebi (Endeavour prawn) are abundant in all waters except the southern part of Australia, but can also be caught in Philippine waters. It is found at depths of 20 to 45 meters. It is said to be caught together with shiba shrimp in some waters, but unlike shiba shrimp, it does not enter brackish water.

It is about 15 cm long and weighs about 17 grams. The entire body is covered with fine hair. Its scientific name is derived from the name of a research vessel, the Endeavour, which surveyed the eastern coast of Australia.

Also called Brown prawn, Endeavour shrimp.

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Revision date: June 15, 2024

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What is Shiromi?

Hirame is a high-quality fish that goes for at least US $50 per kilogram. It can even exceed US $80 per kilogram, depending on the timing and the fish’s body.

Hirame is a typical shiromi (white meat fish) when winter is approaching and a great sushi topping to start off a meal. Also, the taste is so delicate that the original flavor can be cancelled out just by adding too much soy sauce. How the chef expresses this delicate taste is a tribute to his skill and something that foodies look forward to.

In the US, Hirame is often written as “halibut” on the menu of sushi restaurants. Technically the English name of Hirame is Bastard halibut. Hailbut (referring to Pacific halibut) is called “Ohyo” in Japanese. In Japan, the engawa of massive Ohyo is often used as a substitute for Hirame engawa at conveyor belt sushi, but the two are not confused for each other. There is no mistake that Hirame is related to halibut, but they are completely different species. Incidentally, the price of Ohyo is US $3 to $20 per kilogram. It is incomparably cheaper than Hirame.

Also, depending on the restaurant it may be represented in a variety of other ways such as fluke, flatfish and flounder. These terms refer to relatives of Hirame (鮃) or Karei (鰈), but do not indicate any certain species of fish. In other words, there is generally no distinction between Hirame and Karei in the US and to go even further, all white fish are thought to be the same species.

The delicious taste of fish is dependent on the distribution of fat and the amount of inosinic acid. Therefore, fish taste better in the seasons when they have fattened up. On the other hand, people have a hard time distinguishing between types of fish when comparing the tastes of the parts with less fat. The free amino acids in fish meat differ only slightly between different types of fish. In other words, the flavor of all fish is mostly the same. It is only the amount of fat and the amount of the umami component, inosinic acid, that differ between fish, so apparently even sushi chefs cannot distinguish between fish just by eating the back part, which has a low fat content.

This is part of the reason why in the US all white fish is all lumped into the same category and to top it off, the common consensus there is that white fish has no flavor.

At sushi restaurants in Japan, generally there are at least two types of white fish on offer. It is practically guaranteed that Hirame will be in stock in winter. The light flavor unique to this white meat that spreads with each bite maximizes the aroma and sweetness of the vinegared rice. Recently, white fish with high levels of fat such as Kinmedai and Nodoguro, have become standard, high-quality white fish.

The difference between how even these sorts of white fish are handled in the US and Japan is astonishing. That said, flavorless Hirame is not consumed as sashimi or sushi even in Japan. It is served in dishes with strong flavors, like carpaccio. It’s possible that delicious Hirame is just not available in the US.

Related contents: List of White flesh fish

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Revision date: July 16, 2022

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What is Ishigakigai sushi?

Ishigakigai is a shellfish found from Kashimanada northward, Hokkaido, from the Kuril Islands to the Aleutian Islands and even on the west coast of North America. It lives off of plankton in the shallow sandy mud bottoms of the sea at depths of about 50 meters.

Aquaculture in Hirota Bay, Iwate Prefecture, has been successful and it started to appear at the Tsukiji Fish Market starting in about 2008, distributed as Ishigakigai. According to brokers, someone in the business at Tsukiji Fish Market misheard “Ishikage” as “Ishigaki” and the name stuck in the market. While Torigai meat looks black, Ishigakigai looks whiter, so it is also called “Shirotorigai”. The official name is “Ezoishikagegai”.

It starts to become common at the market when the Japanese rainy season ends, at the beginning of summer every year, which is around the end of the Torigai season. It then disappears from the market at the end of summer. A number of sushi restaurants start using it as a substitute for Torigai all at the same time, so Ishigakigai nigiri sushi suddenly started appearing on menus. Frankly, it is somewhat conservative as a nigiri topping but is known for the crunchy texture when biting into it. It also has strong sweetness and umami, which goes exquisitely with Shari. The sushi chef slaps the meat in his hand directly before serving to stiffen it–a way to increase the crunchy texture characteristic of shellfish. Naturally this texture is evidence of its freshness.

As the season of availability is short and the production sites are limited, Ishigakigai often fetches a high price. Those up for sale at the Toyosu Market go for $2 to $4 each. Wild-caught Ishigakigai is rarely found on the market, but when they are, the price is double that of the farmed version.

A relative of the Torigai, the Ishigakigai is rich in amino acids such as taurine, glycine and arginine. It is also resilient and can live for days, even outside its shell.

What is Black tiger shrimp?

Black Tiger is in the category of the largest shrimp that is part of the Kuruma Ebi family and grows to be up to 30 cm. Black Tiger gets its name from the fact that it looks black before it is heated and has stripes like a tiger. The official name in Japan is “Ushi Ebi” but the reason is unknown. The Black Tiger is cultivated heavily in places like China, Vietnam, Indonesia, Thailand and India. It started to be imported from Taiwan in the 1980s to compensate when Japan’s shrimp consumption could no longer be covered by Kuruma Ebi. At the peak, it accounted for 40% of Japan’s shrimp imports. There is a strong impression of shrimp being imported, but small Black Tiger can actually be caught in Japan from Tokyo Bay southward.

Black Tiger has a strong sweetness and firm meat but maintains its plumpness even when cooked with heat. It is known for the red color that appears when heated. The appearance and texture when eating Black Tiger is said to be similar to Kuruma Ebi, which is known to be a shrimp of luxury, so it is a very popular shrimp in Japan. It is used not only as a sushi topping, but in a wide variety of dishes, such as for deep-fried shrimp or Tempura.

For sushi restaurants, shrimp that has been boiled and had the head and shell removed is imported in vacuum-sealed bags. Once defrosted, it can be used as a sushi topping without any further preparations. At conveyor belt sushi restaurants it was even once presented as Kuruma Ebi.

One problem with Black Tiger, which is the mainstream farmed shrimp, is that it has little resistance to illness, and cannot be farmed in the same place continuously. Therefore, Black Tiger farming volume has dropped and currently Vannamei Ebi (Whiteleg shrimp) is becoming a major force in shrimp farming.

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Revision date: July 9, 2021

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