Sushibog is wrtten by researchers of Sushi University

Where should soy sauce be applied to the sushi?

A photo of applying shoyu — When dipping sushi into the soy sauce, it is most common to turn it slightly (almost upside down) and dip the topping side—not the rice.

Soy sauce is more than just a condiment for sushi—when used properly, it enhances the flavor of the sushi topping and brings out a perfect balance with the vinegared rice, which is already delicately seasoned. However, using it incorrectly can easily upset this harmony.

The most delicious way to eat sushi at restaurants where the sushi chef applies Nikiri shoyu (a soy sauce mixture perfectly evaporated with sake) for you is just the way it was prepared. However, at restaurants where sauce is not applied for you, the sushi is eaten by dipping it in soy sauce. The soy sauce used for dipping is provided for you at the counter or table. Many restaurants use the same evaporation formula for the dipping soy sauce.

Soy sauce for dipping is put into a small dish for use, but don’t put in too much. It depends on the depth of the small dish, but the diameter of the circle of soy sauce after being poured should be approximately 25mm.

When dipping sushi into the soy sauce, turning it upside down (although it will be somewhat tilted) and dipping the topping seems to be the most common method. If you keep the topping on the bottom when you put the sushi in your mouth, the flavors of the soy sauce and the fish are in complete harmony and the delicious taste spreads through your mouth. There is also an opinion that turning the sushi upside down for dipping is unacceptable practice. There are also some with the opinion that whether to eat with your hands or chopsticks depends on the situation.

Make sure not to get any soy sauce on the vinegared rice (shari). You don’t want to add unnecessary saltiness to the Shari, which has already been seasoned. It would be a terrible waste to cancel out the exquisite balance of the topping, wasabi and Shari with the saltiness of soy sauce.

What is Uwami and Shitami?

Large fish that are caught are always kept and transported on their side with their heads facing left from the port to the market and to the restaurant where they are served. The part of the fish facing down when in this position is called “Shitami” or the “bottom body” and the part facing up is called “Uwami” or the top body. The Uwami costs more than Shitami. This is because the Shitami takes on the weight of the Uwami, reducing the freshness and possibly causing cracks in the body (cracking occurs on the edges of the muscles).

This mostly applies to Pacific bluefin tuna (tuna that is consumed without any freezing after being caught). At any rate, since this fish costs hundreds of dollars per kilogram, a full-grown fish may be worth more than a luxury sports car. Therefore, from the time they make their catch, the fishermen work quickly, which affects all aspects of the quality. Most of all, this work affects the price. A Pacific bluefin is never placed directly on the deck of the ship. If a fish weighing 100 kg or more is set directly on the hard deck, its own weight would cause injury to its surface. Naturally, any damage or injury to the fish reduces the price. Instead, each fish is laid on a soft, spongy mat to protect its skin surface. Next, the blood is drained, the spinal cord nerves are destroyed and the fish is submerged in ice water. It might be easier to understand if you imagine handling a luxury vehicle, like a Ferrari, rather than a tuna fish.

Incidentally, the idea behind keeping the “Left side up (or prioritized), right side down,” is a fixed Japanese etiquette, passed down through China from the Asuka period. Perhaps the reason fish are also served for eating and photographed with the head on the left side is due to this influence as well. However, this is only a fixed practice within Japan.

At sushi restaurants, one of the many things the chef teaches their apprentice is to, “Start using purchase fish from ‘Shitami’.” Once a sushi topping is prepared, it may be served for several. It’s hard to imagine that the Shitami would start to go bad during these several days, but it is attention to these small details that make a master sushi chef.

Related contents: TYPES OF TUNA

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Revision date: June 13, 2023

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What is “Suteshari”?

A photo of rice tab — The sushi chef is trying to take the vinegared rice from the rice tab.

Shari — vinegared rice used for making sushi — is typically kept in a wooden rice tub (known as a hangiri) and placed within easy reach of the sushi chef’s dominant hand. With a swift and practiced motion, a skilled sushi chef scoops out just the right amount of rice — often several hundred grains — to shape a uniform shari dama (vinegared rice ball) for a single piece of sushi.

A photo of shari dama — The appearance of shari dama

It is said that experienced chefs can do this with a margin of error of only a few grains, thanks to years of rigorous training and muscle memory.

However, not all chefs have reached this level of precision. Some may inadvertently take too much rice, only to pinch off the excess and return it to the rice tub. This practice is called “suteshari” (捨てシャリ) — literally, “discarded rice.” Despite the name, the rice is often not truly discarded but rather returned to the communal tub, which can be a source of concern both in terms of hygiene and professionalism.

We estimate that more than half of sushi chefs engage in this practice, especially when they find it difficult to judge the proper proportion of shari to complement a topping (neta) before the piece is assembled.

While some may view it as a minor adjustment, seasoned sushi connoisseurs see suteshari as a telltale sign of insufficient training or inattentiveness. Movements behind the counter are closely observed.

From a sanitary standpoint, suteshari presents another issue: when sushi is made in high volume, residual rice that has absorbed moisture or fish juices from discarded portions may accumulate at the bottom of the tub, compromising cleanliness and potentially affecting the flavor of subsequent pieces.

A photo of making nigiri sushi — The sushi chef is shaping the shari dama.

That said, suteshari is not entirely taboo. When sushi is served in a shared presentation on a platter (moriawase), visual uniformity is essential. However, when served omakase-style as individual pieces directly to the guest, uniformity is not required.

Even Jiro Ono, the revered sushi master of Sukiyabashi Jiro in Ginza — once awarded three Michelin stars for 12 consecutive years — has occasionally been seen discarding rice to fine-tune his nigiri. (The restaurant is no longer listed in the Michelin Guide due to its exclusive reservation policy.)

In the end, suteshari is a nuanced gesture — neither wholly negative nor praiseworthy — but rather a window into the discipline, training, and philosophy of the chef behind the counter.

Related contents: WHAT RICE TO USE FOR SUSHI?

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Revision date: June 4, 2025

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What is “Hagashi”?

There is a part on the tuna belly called “Sunazuri (gizzards)” or “Zuri” . Normally “Jabara,” with the diagonal white lines is the king of tuna, but the fatty tuna is spoiled if the white lines are left in your mouth. Also, on the dorsal side there is a part that produces chutoro called wakaremi.

A photo of Maguro hagashi nigiri — The appearance of Maguro hagashi nigiri

This part is also complex with hard, white lines throughout that we want to avoid eating. Instead, the knife cuts along those lines, gently removing the fish meat from them, making “Hagashi.” If the chef is not skilled, this cut will take time and extra meat is left behind. This is delicate work, making for a delicious and satisfying experience.

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Revision date: August 24, 2024

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Does the taste of wasabi differ depending on the grater?!

Sushi restaurants use two types of tools for grating wasabi. One is a metal grater, and the other is called “samegawa” (shark skin), which consists of shark skin attached to a wooden base.

Using a material as fine as shark skin allows the aroma to first escape through the nasal passages, resulting in a taste that is initially sweet and gradually becomes spicier. This process breaks down the wasabi cells, creating a grated wasabi with high viscosity and rich flavor.

On the other hand, the metal grater has a coarser surface compared to the shark skin grater, resulting in grated wasabi with lower viscosity and a grainy texture. However, the shape of the surface protrusions varies, so this is merely a general rule.

Additionally, copper graters used by sushi chefs have antibacterial properties, making them safe for handling ingredients. Using a copper grater allows you to grate wasabi without crushing the fibers, resulting in a light and fluffy texture.

Finally, an interesting point is that the taste of the wasabi even changes depending on whether it is turned clockwise or counter-clockwise while grating. Of course, this depends on the orientation of the protrusions on the grater surface and is not related to the type of grater.

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Revision date: June 3, 2025

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Strong belief that fish is only about freshness

In some cases, the strong belief that fish is only about freshness, may prevent you from tasting the true value of the fish. For example, slicing up a fish that was just swimming, in front of the customer. The umami flavor is weak at first so while the texture is tough (a unique, crunchy feeling), the flavor is lacking. But the idea that freshness is equivalent to deliciousness continues still. This is a typical case of faith in freshness overtaking the actual taste.

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Revision date: April 16, 2018

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What is the difference between the taste of marbled and lined fatty tuna?

It is often said that when you eat Otoro, it melts in your mouth like a snowflake. With its smooth texture and rich flavor, it is enormously popular. Otoro is located on the belly side near the head and can be divided into two types.

A photo of otoro shimofuri — The appearance of Otoro shimofuri

Marbled tuna (Shimofuri) is the part in which it looks like the fat has fallen like a frost and melts like snow on your tongue then leaving only the umami taste. By cutting thinly and widely at an angle to the saku, a delicate flavor and aroma are produced.

A photo of shimofuri meat — This is beef shimofuri meat.

By the way, “shimofuri” refers to the finely woven pattern of fat between the muscle fibers of meat. The fat between the muscle fibers is called “sashi,” and the finer it is, the higher the quality of the meat.

A photo of Otoro jabara — The appearance of Otoro Jabara

The lined fatty tuna (Jabara) is the part that has white fat lines running through it. When you first take a bite, surge of aroma and umami flavor fills your mouth. After that, the potent fatty umami fills your mouth. Cut the Jabara into thick, slightly shorter pieces and make nigiri sushi.

A photo of jabara shape — The appearance of jabara

The original meaning of jabara is a structure of repeated “mountain folds and valley folds” made of a wide variety of materials. The name was chosen because of the similarity of this shape to the appearance of otoro. In English, it is called bellows.

The way the fat melts in your mouth differs between Jabara and Shimofuri, so which you like better depends on preference.

A photo of otoro aburi — The appearance of Otoro aburi

Some people find the fat in Otoro to be too rich. By searing it, the excess fat is removed and the moisture is evaporated, so the umami components are concentrated, and adding a savory aroma enhances the flavor.

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Revision date: July 2, 2025

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Can’t-miss Tokyo sushi toppings (Meji Maguro)

Meji Maguro (AKA: Meji) caught in fixed net fishing is one type of sushi topping that you really should try. Meji is the larval fish of Pacific bluefin tuna, made and served at expensive restaurants, but not usually available as Edo-style sushi. Its fat is lighter and it doesn’t have the impact that fatty tuna has. Efforts are put into seasoning to avoid this. Using a pinch of ginger, Japanese basil or onion between the topping and rice, along with the wasabi, really brings out the fresh flavor of the young fish as well as the sweetness of this fatty part.

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Revision date: March 26, 2018

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Why doesn’t rice stick to the sushi chef’s hands?

A photo of shaping nigiri sushi — Sushi chef is making nigiri sushi.

One of the pleasures of sitting at a sushi counter is watching the sushi master work his craft.

He holds the topping between the index finger and thumb of his left hand while simultaneously grabbing the shari (vinegared rice) with his left hand. He gently squeezes the shari and then moves the topping from his left hand to the top of that shari in a fluid motion. This entire process of shaping the shari to the finished piece of sushi takes less than six seconds. Every movement is precise and purposeful.

However, no matter how many pieces the chef makes one after another, you’ll never see a grain of rice stick to his hands. If you or I were to make even one piece of sushi, our hands would be covered in rice. So why doesn’t it happen to them? Their hands don’t look oiled. Perhaps sushi chefs have especially smooth or slick hands compared to us average Joes?

Of course not. This is actually thanks to the vinegar.

The chefs keep a bowl of vinegar close by, which they constantly use to wet their hands. If the sushi chef’s hands are dry, the rice grains tend to stick to them, so the rice needs to be moistened just enough.

This is called “Tezu” or vinegared water, which both disinfects the hands and cools their palms. When the vinegar evaporates, it takes the heat from the hands with it.

Normally hands reach temperatures of 33-34 degrees Celsius (91-93 degrees Fahrenheit), but sushi chefs cool their hands to approximately 30 degrees Celsius (86 F). This transfers the heat from the hands to the shari, keeping it from getting sticky. In other words, not a single grain of rice sticks to their hands.

Also, the stickiness of rice is mainly caused by starch (especially amylopectin) gelatinizing with water and heat, but vinegar contains acetic acid, which acidifies the pH, so under these conditions, the structure of the starch changes slightly, inhibiting the formation of stickiness (the sticky component).

Additionally, vinegared rice becomes sticky if there is too much moisture, and conversely, if there is too little moisture, it becomes dry and difficult to shape. Therefore, the moisture content and temperature are carefully adjusted to achieve the perfect balance.

In short, it’s not magic or special skin — it’s the calculated use of vinegar, moisture, and temperature control that keeps sushi chefs’ hands rice-free.

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Revision date: June 16, 2025

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Why is freshly-caught fish allowed to age?

The most delicious time to eat fish differs depending on if it is served as sashimi, as sushi, or boiled. Fresh does not necessarily mean delicious. For example, Japanese Amberjack should be used in sashimi 3-5 days after being caught, in sushi a week after being caught and it can be used in a stew or boiled once it turns black around the edges. This is because the inosine acid, which is responsible for the umami taste, increases after rigor mortis ends and understanding the timing of the peak in flavor is up to the skill of the sushi chef.

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Revision date: March 12, 2018

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Why does the bill more when ordering sashimi at a prestigious restaurant?

Thicker cuts of fish are used for sashimi than for sushi. Depending on the restaurant, the equivalent of three pieces of sushi may be used in one cut of sashimi. In other words, two pieces of sashimi is the same as six pieces of sushi. At a restaurant where one piece of medium fatty tuna sushi is priced at JPY 1000, simple arithmetic prices medium fatty tuna sashimi at JPY 6000. Just a small order of assorted sashimi often costs more than JPY 10,000. Be careful.

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Revision date: March 5, 2018

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Why are two pieces of nigiri sushi made at once?

Have you ordered Nigiri sushi and been served two pieces on one plate?

A photo of Conveyor belt sushi — One plate has two pieces of nigiri sushi.

This isn’t something that happens at a conveyor belt sushi restaurant. It can happen at a sushi restaurant with a counter.

There are multiple theories as to the reason for this, but the most likely one is as follows.

The reason sushi is served in sets of two pieces is that this practice is left over from long ago (the Edo period), when pieces of sushi were made large, like onigiri, and difficult to eat. At some point (it’s unclear when), these were just cut in half, making two pieces that led to what we see today (there are multiple theories about when this happened).

However nowadays, if you were to eat two pieces of each topping, you won’t be able to enjoy as many different kinds, so customers sitting at the counter are served only one piece at a time. So then why do other restaurants continue to prepare two pieces at once? This may be in order to improve the efficiency of the sushi chef’s work. Also, regular customers may see toppings others are ordering and ask for the same one. This helps reduce the workload of the sushi chef.

But there are also some toppings that are better to eat in pairs.

For example, conger eel tastes completely different when one piece is eaten with salt and the other seasoned with sweet sauce. Serving the part of the eel closer to the head skin-up and the part closer to the tail belly-up also offers different textures; skin-up offers a smooth texture while belly-up offers a fluffy texture. In addition, the head and tail simply taste differently. Since the back and belly of fish like bonito and mackerel have different fat content, it can be better to order two pieces at a time in order to fully experience each of the individual qualities of the fish.

The sushi chefs at your favorite restaurant know your preferences well. Depending on the type of fish, they may serve you two pieces of the back side, which has a more fishy flavor, without saying anything.

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Revision date: May 29, 2025

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Why don’t I notice the fishy smell in sushi restaurants?

Many overseas visitors who are not accustomed to eating fish often find the fishy smell off-putting. This odor is mainly caused by a compound called trimethylamine, which forms when bacteria break down trimethylamine oxide, a substance abundant in fish that contributes to umami flavor. As time passes, ammonia is also generated, further intensifying the odor.

Trimethylamine begins to form after the fish dies. Therefore, the key to minimizing this smell is to process the fish as soon as possible after it is caught. Removing the slimy coating on the skin, as well as any decaying internal organs or blood, also helps reduce odor. It is essential to rinse the fish with water.

After cleaning, the fish is typically lightly salted and refrigerated. After some time, the salt is rinsed off using saltwater with a salinity of about 3%, similar to that of seawater. This step is crucial because rinsing with fresh water would cause the fish to reabsorb moisture through osmosis, making the previous dehydration process ineffective and leaving the fish with a watery texture.

Bacterial growth is further suppressed by refrigeration, which is why sushi toppings are kept cold. Additionally, since trimethylamine is alkaline, it can be neutralized by vinegar, which is acidic. Soaking fish in vinegar not only helps eliminate odor but also reduces surface bacteria.

In short, sushi restaurants take meticulous steps to prevent bacterial growth and eliminate fishy smells, ensuring that customers enjoy fresh, clean-tasting sushi.

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Revision date: June 10, 2025

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Is sushi eaten with your hands? Or should you use chopsticks?

A photo of Edo-period nigiri sushi — This is Edo-period nigiri sushi, similar in size to onigiri.

During the Edo period in Japan, nigiri sushi became extremely popular and was sold at street stalls (yatai). It was similar to what we now call onigiri, eaten by hand. The term “onigiri” was used because the nigiri sushi of that time was about two to three times larger than today’s version. After finishing their meal, customers are said to have wiped their hands on the stall’s curtain (noren). As an aside, historical records describe Edo as a rather unsanitary city at the time, and this practice serves as evidence of that.

a photo of hand-washing devices (groove) — This is hand-washing devices (groove).

Later, in the 1950s, sushi restaurants began installing hand-washing devices (grooves) on the customer side of the counter. Instead of using hand towels, customers would wash their hands in the water and moisten their fingers before eating sushi. Some traditional sushi restaurants in rural areas still have these grooves today.

A photo of uni nigiri sushi — Recently, some high-end sushi restaurants have started serving nigiri sushi directly from the sushi chef.

Recently, some high-end sushi restaurants have started serving nigiri sushi directly from the sushi chef. This is particularly common with delicate ingredients like uni, which are prone to falling apart. In this case, customers are forced to eat nigiri sushi with their hands.

In the old days, Sushi was originally a food eaten with your hands.

a photo of Yubifuki — Yubifuki refers to cloths or gauze provided mainly at sushi restaurants for customers to keep their fingertips clean while eating sushi.

Even, for example, if you are in a prestigious sushi restaurant in Ginza, you can still eat with your hands. You can actually use your hands to eat the ginger (gari) too (Some guidebooks state that gari should be eaten with chopsticks, but no sushi chefs would ever say such a thing). Restaurants that prefer you to eat with your hands will provide an extra, smaller towel called yubifuki for cleaning your hands between sushi, along with the normal hand towel (Oshibori towel). Even then, feel free to use chopsticks if you prefer.

Anyway, using chopsticks for the first time can be challenging, but don’t worry – here is the ultimate guide to becoming an expert at picking up your favorite sushi without damaging it. You’ll learn how to use chopsticks like a pro.

Follow these simple steps to use chopsticks like an expert:

Hold the chopsticks by their thickest end.
Place the chopstick on the lower end of your hand in the gap between your thumb and index finger.
The chopstick on the top goes on the fingerprint of the thumb and index finger.
To pick each piece of sushi, move the upper stick with the help of your thumb, index, and middle fingers.

Follow the steps above and soon, you’ll be the one teaching your friends! Now you know how to pick up nigiri sushi with chopsticks!

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Revision date: June 17, 2025

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Why is sushi with tuna topping so expensive?

A purchase of raw tuna costs at least JPY 30,000 per kilogram. Furthermore, good tuna is judged not only by taste, but appearance is also highly regarded.

The surface is gradually oxidized by letting it sleep (mature) and the sushi chef makes sure that parts are cut of as they change color, when the timing is perfect for both the taste and appearance. In other words, skin is taken from the freshly purchased tuna, the meat of the fish darkened by blood (the blackened area that can’t be used as sushi toppings) is removed, the parts that have changed color are shaved off and then only the remaining, best parts used as toppings are left.

This is why the price is high.

Related contents: TYPES OF TUNA

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Revision date: February 5, 2018

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