Edomaesushi | Sushiblog－Sushiuniversity

How is Shari’s weight decided?

A photo of shari dama (sushi rice ball) — The weight of the sushi rice ball is determined the moment the sushi chef forms it.

Nigiri sushi sold at street stalls during the Edo period is said to have been roughly the size of a small rice ball today, weighing about 50 to 70 grams per piece. According to historical records such as Morisada Manko (守貞漫稿), eating just two or three pieces was considered a sufficient light meal. Eventually, complaints that the sushi was “too large and difficult to eat” led to it being halved in size and served two pieces at a time, though there are several theories about why this change occurred. This adjustment allowed diners to enjoy a greater variety of toppings in a single visit.

The weight of shari and toppings is actually decided by each restaurant; there is no industry standard.

So how did this weight come to be? The answer lies in a unit of rice that has been deeply ingrained in Japanese life.

In Japan, the smallest unit for measuring rice is called ichigo (一合), which equals 150 grams (180 cc). This is also considered a standard portion for one meal, and household rice cookers often have markings based on multiples of this unit. Cooking an ichigo yields approximately 300 to 330 grams of cooked rice. While actual consumption varies depending on age and gender, the concept of “ichigo equals one meal” has been established for centuries. This unit has been passed down not only in households but also in sushi restaurants, where chefs use it to calculate the required cooking volume and determine how much rice to prepare at once.

This unit is also scalable: ten times ichigo equals ishou (一升). Until about 30 years ago, it was common for sushi restaurants to cook nishou (二升) of rice at a time, and commercial rice cookers sized for this purpose were available. Today, chefs typically cook rice according to the number of reservations, often calculating one serving as a little over ichigo.

Looking further back, during the post-war rationing period, there was a “commissioned processing system” where rationed rice could be brought to sushi shops for processing. Bringing ichigo of rice to a sushi shop would get you seven pieces of nigiri sushi and one nori roll, equivalent to about ten pieces of nigiri. Working backward from this system, it is estimated that the rice weight per piece in the post-war period was approximately 30 to 33 grams.

This weight served as a standard benchmark for some time after the war. Gradually, alongside changes in food culture, this standard also shifted. Responding to customer requests to enjoy more sushi toppings, the amount of rice per piece gradually decreased. By the late Showa period, it was around 20 grams. Today, in the Reiwa era, the mainstream is 10–15 grams per piece in central Tokyo sushi restaurants and 15–20 grams in regional areas.

Sushi chefs carefully consider the thickness of the fish, its fat content, and the temperature and humidity of the rice to achieve the “balance that tastes best in one bite.” In recent years, partly due to rising ingredient costs, there has been a trend toward reducing the rice even further. Some pieces now weigh less than 10 grams, though it is said that reducing them any more makes it difficult to discern subtle differences in flavor, especially in white fish.

The weight of the rice is not merely a matter of quantity; it represents the “art of the bite,” shaped by 200 years of Japanese food culture and aesthetic sensibility.

What is the difference between Karei and Hirame?

A photo of Bastard halibut (Hirame) — The appearance of Bastard halibut (Hirame)

This title might seem like a uniquely Japanese question. However, in neighboring countries like Korea and China, flounder (karai) and halibut (hirame) are also commonly eaten, and efforts are being made to cultivate them.

In many other countries, however, these fish are not distinguished and are often lumped together as “flatfish.”

One reason is the broad range of species covered by the English term “flounder.” For instance, many species like flounder, plaice, halibut, lemon sole, common dab, Pacific Dover sole, and fluke are all grouped under “karei.” Even the names alone can be confusing.

The common method to distinguish hirame and karei is the rule that when placed belly-side down (the white side), the hirame faces left and the karei faces right. However, there are exceptions like Numagarei (Starry flounder).

Species in the Pleuronectidae family, whose eyes are on the right side, are known as “righteye flounders,” while those in families such as Paralichthyidae and Bothidae, with eyes on the left, are called “lefteye flounders.”

Similarities and Differences Between Karei and Hirame

Both karei and hirame belong to the order Pleuronectiformes and share very similar shapes and colors. They both have flat bodies, are asymmetrical, and possess the unique characteristic of having both eyes on one side of their body.

What is Karei?

An Illustration of Karei — The Illustration of Karei

Flounder encompasses a vast number of species with a wide distribution range. In Japanese coastal waters alone, approximately 40 species have been identified, including Magarei (Yellow striped flounder), Meitagarei (Ridged-eye flounder), Ishigarei (Stone flounder), and Makogarei (Marbled flounder). The species caught also vary by region.

As they are relatively inactive fish, their flesh is characterized as soft and rich in fat. They feed on small fish, ragworms, and small crustaceans, resulting in a small mouth shaped like a “pursed mouth.” Additionally, their eyes are located on the right side of their body.

While fresh specimens can be eaten as sashimi, they generally have a slight distinctive flavor. Therefore, they are typically enjoyed cooked through methods like simmering, frying, deep-frying, or drying.

What is Hirame?

An Illustration of hirame — The Illustration of Hirame

Compared to karei, hirame has fewer species and a narrower distribution, making it relatively rare. Its scientific name is Paralichthys olivaceus, and it is a premium fish found in the coastal waters of Japan and Korea.

Hirame has well-developed muscles for agile movement, resulting in firm flesh. It has a large mouth and sharp teeth for catching small fish and crustaceans, and its eyes are located on the left side of its body.

When eaten raw, it has a crisp, firm texture that turns tender and flaky when cooked. It’s known for its mild flavor and delicate umami. It is popular as a premium ingredient for sushi and sashimi, and in French cuisine, it is also used in main dishes like meunière.

Its peak season runs from late autumn to early spring, with the winter variety, “Kanbirame,” boasting particularly rich fat content and exceptional flavor.

Conclusion

While karei and hirame may look similar, they have distinct differences in taste, texture, and ecology. In Japan, summer Makogarei (Marbled flounder) and winter Bastard halibut (Hirame) are considered premium fish, highly prized in sushi restaurants and traditional Japanese restaurants. Understanding these differences enhances the enjoyment of dining at sushi establishments.

Is Tezara considered bad manners?

Tezara's Image Illustration — Focus on the hand not holding the chopsticks

When sauce is about to drip, do you catch it by cupping your hand like a plate with the hand opposite your chopsticks? This is commonly called “Tezara (手皿: Te means hand and zara means plate).” It often appears on Japanese TV during meal scenes.

While it might seem elegant, it’s actually considered bad manners in Japanese dining etiquette, so it’s best to remember this. You should be especially careful during important occasions. The basic etiquette for Japanese cuisine is to hold the bowl or dish in your hand while eating, so the correct way is to use the sauce in a small side dish, not your hand.

However, there are times when small side dishes aren’t provided, like when eating out or at home. In those cases, the basic Japanese approach is to hold the bowl itself close to your mouth for dishes with sauce. Alternatively, you can use techniques like lightly cutting the sauce with the tips of your chopsticks before bringing it to your mouth to eat neatly without using your hands.

Why is using your hand as a plate considered bad manners? If sauce drips onto your hand and stains it, you’ll need to wipe your hands with an oshibori (wet towel), creating extra laundry. Oshibori are meant for wiping hands before eating. If they get stained with food sauce, they may require stain removal, causing trouble for the restaurant.

Furthermore, while it’s common, seeing someone use their palm as a plate and then bring the food to their mouth can feel somewhat unhygienic and vulgar, even if the person themselves doesn’t mind. Depending on the situation, it’s considered bad manners during a proper meal.

dining manners — In Japan, holding bowls and small dishes is considered polite.

In Japanese dining culture, holding bowls and small dishes is considered polite. Proper etiquette dictates lifting bowls and soup bowls to your mouth, while flat or large dishes should not be lifted—specific manners exist for each type of vessel. Using a serving dish instead of tezara is rooted in these uniquely Japanese dining customs.

Of course, during casual meals at home or with friends, you might unconsciously use your hand as a plate. While it often isn’t a major issue in daily life, it’s especially important to refrain from doing so at formal occasions, kaiseki dinners, or when dining with seniors. Being mindful of etiquette according to the situation will make your dining manners appear more refined.

It’s a gesture that anyone can easily do, but it’s best to avoid it at formal occasions. It may even look as if you’re drawing attention to a spill, so using a side plate or small dish is always the better choice.

Does freshness really determine the best time to enjoy food?

Images of various fresh ingredients — Vegetables, fish, and meat each have their own “peak season” when they taste their absolute best.

It’s often said that when it comes to food, freshness is everything. However, greater freshness doesn’t always mean better flavor. Each type of food, such as vegetables, fish, and meat, has its own “peak ripeness” when it tastes its best.

When it comes to fish, the strong belief that “freshness is everything” can sometimes prevent us from fully appreciating its value. Consider fish that are still swimming before the customer’s eyes and then prepared on the spot. While its texture is unique and firm, its umami is weak, and its flavor is lacking. Yet, the notion that “fresh equals delicious” remains deeply ingrained, creating a mindset where belief in freshness outweighs actual flavor.

Let’s take this opportunity to reexamine what truly constitutes the perfect time to enjoy food at its most flavorful.

Vegetables, after harvest, continue breathing, consuming their internal sugars and nutrients while losing moisture, which causes their freshness to decline. To suppress this respiratory activity, effective methods include cold storage, packaging that prevents moisture evaporation, or storage in an environment with low oxygen and high carbon dioxide levels.

On the other hand, vegetables like potatoes and sweet potatoes become more delicious through aging. When potatoes are stored at low temperatures, cold-induced sweetening occurs, breaking down starch into sugar and increasing sweetness. Sweet potatoes also undergo curing after harvest (It forms a protective cork layer, preventing pathogen invasion and suppressing decay). Storing them at a specific temperature and humidity allows the starch to saccharify, enhancing their sweetness and sticky texture. However, apart from these specific examples, vegetables generally lose their freshness over time, so eating them right after harvest is when they taste best.

The optimal time to eat fish varies by species. Coastal migratory fish like sardines and mackerel spoil quickly, making freshness extremely important. These contain EPA, a beneficial fish oil, but since it is vulnerable to heat and oxidation, it is best to choose fresh, high-quality fish for raw consumption.

Even among blue-backed fish, large pelagic migratory species like tuna and yellowtail are different. If they are too fresh, their umami flavor is weak. The umami components increase once rigor mortis subsides and aging begins, reaching their peak flavor.

Furthermore, white-fleshed fish like red seabream and flounder also require careful handling. While Ikejime techniques are used to preserve freshness, freshly caught fish offer a firm, crisp texture. However, umami compounds increase after rigor mortis sets in, meaning “freshness” doesn’t necessarily equate to “deliciousness.”

Sushi chefs fully understand that the ideal eating time varies by fish species. They also fully understand that freshness ensures good texture. On top of that, they strive to balance seemingly conflicting conditions like optimal eating time and texture. In Japan, it’s not uncommon for fish caught by local fishermen to arrive at major city fish markets the same day. Some even arrive at the market still alive. So, freshness alone is something anyone can obtain.

Next, let’s look at meat. Chicken has a small body, and rigor mortis sets in quickly, within just 1 to 2 hours after death, allowing umami to develop rapidly. On the other hand, it also loses freshness quickly. Therefore, it’s safe to say that freshness is absolutely vital for chicken.

On the other hand, large animals like pork and beef require time for rigor mortis to subside, followed by maturation. The recently popular “dry aging” is a traditional method where meat is matured for about a month at 1-2°C while being exposed to airflow, resulting in tender, flavorful lean cuts. Additionally, “wet aging,” practiced in Japan for centuries, involves vacuum-sealing the meat and resting it at 0–2°C for 1–2 weeks, a method that also enhances umami.

Thus, meat isn’t necessarily more delicious the fresher it is; rather, aging increases umami components like inosinic acid, leading some to even say “some even say it tastes best when it’s on the verge of spoiling.” In other words, freshness and deliciousness don’t always go hand in hand.

In other words, the notion that “freshness equals deliciousness” isn’t always accurate; each ingredient has its own “peak flavor” period when it tastes best. What matters is not blindly trusting freshness, but understanding the characteristics of the ingredient and discerning its optimal eating window.

Where is the border between otoro and chutoro?

A photo of otoro — The appearance of otoro

First, let’s confirm where chutoro and otoro are located on the tuna using a cross-section diagram of the fish’s midsection.

An illustration of Cross section — An illustration of cross section

Looking at the tuna cross-section, the center part is red meat (Akami), while the surrounding areas closer to the skin are medium fatty (chutoro) and extra fatty (otoro). However, the borders aren’t clearly defined like this, so it’s merely a guideline. If the cut is closer to the tail, it will be just red meat.

Next, when the tuna is dissected, as shown in the illustration below.

An illustration of kuromaguro cutting daigram

The tuna is broadly divided into three main sections from the head: “Kami (Near the head)”, “Naka (Central section)”, and “Shimo (Near the tail)”. The back side is divided from the head downwards as “Sekami (se means back),” “Senaka,” and “Seshimo,” while the belly side is divided as “Harakami (hara means belly),” “Haranaka,” and “Harashimo.” Sushi chefs purchase these sections by width, measured from the index finger to the little finger. This width corresponds exactly to the size of one piece of sushi.

Now, let’s get to the main topic.

Basically, “otoro” refers to the fatty belly section of bluefin tuna or southern bluefin tuna. While various tuna species exist, this term is limited to bluefin and southern bluefin tuna. The term “otoro” isn’t applied to yellowfin or bigeye tuna, though yellowfin tuna can still be fatty. Japanese supermarkets sometimes use the term ‘toro’ for promotional purposes. In-season Albacore (bincho tuna) has exceptionally rich fat, and that cut is sometimes called “bintoro.” Depending on the cut, it can be divided into truly otoro-like otoro and otoro closer to akami-like chutoro.

Otoro generally includes all of the harakami and part of the haranaka. Furthermore, otoro also exists in the kama section near the pectoral fins. Otoro, much like marbled beef, is marbled with white fat. This gives it a rich, melt-in-your-mouth texture. However, some sushi chefs dislike it being too fatty and prepare it as aburi (seared) or zuke (marinated in soy sauce) to balance it with the shari (vinegared rice). Since otoro yields less per fish than akami or chutoro, its price is inevitably higher.

Chutoro, on the other hand, is found on both the belly and the back. It has a base of lean red meat with patches of white fat mixed in. It balances the savory flavor of the lean meat and the sweetness of the fatty tuna, making it universally popular. It consistently ranks among the top favorite sushi toppings for Japanese people. Some parts of the back section also yield a prized cut called setoro. In sushi restaurants, it is the second most expensive tuna cut after otoro.

Incidentally, farmed bluefin tuna and southern bluefin tuna tend to have a higher proportion of fatty parts (toro) compared to wild tuna. This is because they are raised in confined cages with limited exercise and are fed high-fat feed.

The question then arises: where exactly is the boundary between otoro and chutoro?

In reality, there is no clear-cut definition. The distinction is made by tuna wholesalers and sushi restaurants based on years of experience and practical knowledge.

One initiative in producing regions involves branding fish. When certifying branded fish, various criteria are used. One of these is the fish’s fat content. This is objective data and significantly impacts the fish’s deliciousness. The method involves simply touching the fish with the tip of a measuring device, taking only a few seconds. For example, the peak fat content of mackerel imported from Norway to Japan is reportedly around 25-30%.

For otoro, this value is over 20% and can reach 40%. Chutoro is often said to be 15-20%, but such standard values actually don’t exist.

Sushi chefs determine whether it’s chutoro or otoro by cutting the purchased portion into akami, chutoro, and otoro. If the fat content is 15%, it should be classified as chutoro, but if the sushi chef says it’s otoro, then it becomes Otoro.

What is Daikon oroshi?

A photo of daikon oroshi — Grilled sanma is always served with grated daikon radish.

First, let’s look at the meanings of the words.

“Daikon” refers to a type of radish, and “oroshi” means “grated.”

“Oroshi daikon” refers specifically to grated daikon itself, while “daikon oroshi” can mean either the grated daikon or the tool used to grate it, called an oroshi-gane in Japanese. The distinction can be a little tricky.

Vegetables that are commonly grated include daikon, carrots, turnips, yams, potatoes, onions, lotus roots, and cucumbers. Fruits such as apples and pears can also be grated.

About Daikon

Daikon is an essential vegetable in Japanese cuisine. It is considered one of the oldest vegetables in the world and was already cultivated in ancient Egypt. Daikon is generally classified into three types: European, Chinese, and Japanese. It was introduced to Japan from China, and suzushiro, one of the “Seven Herbs of Spring,” refers to daikon.

Over time, daikon has developed into hundreds of regional varieties. Since the 1970s, however, the “Aokubi daikon (青首大根),” known for being juicy, mild, and slightly sweet, has become the most widely consumed variety.

Typical dishes featuring daikon include pickles, oden (a Japanese hot pot), and buri-daikon (yellowtail simmered with daikon). Although daikon rarely plays the leading role in a dish, it is an important supporting ingredient that adds depth to many recipes.

About Daikon Oroshi

As mentioned earlier, daikon oroshi means grated daikon. It has a refreshing spiciness with a hint of sweetness and is often served with grilled fish in Japan.

When preparing daikon oroshi, the juice is not squeezed out. Instead, it is placed in a strainer so that excess water drains naturally. The flavor varies depending on which part of the root is used:

The top is juicier and sweeter.
The tip is drier and spicier.
The middle has a good balance of both.

The grating method also affects the texture:

Grating vertically produces a fine, smooth texture.
Grating diagonally results in a coarser texture with more noticeable daikon fibers.

No matter which part of the daikon is used, the skin should be peeled thinly before grating. To grate it, hold the daikon vertically against the grater, pressing down and rotating it in a circular motion to cut across the fibers.

Role and Uses of Daikon Oroshi

Daikon oroshi has long been valued as a condiment because it aids digestion. It is especially important when eating oily fish such as yellowtail, fatty tuna, or mackerel sashimi. Without daikon oroshi, the fish oil repels the soy sauce, making the dish less pleasant to eat.

Popular ways to enjoy daikon oroshi include:

With grilled fish: Pairing a bite of fish with daikon oroshi balances the fish’s richness with a refreshing spiciness. Adding a touch of soy sauce enhances the flavor even further.

With tempura: Instead of placing it directly on the tempura, mix daikon oroshi into the dipping sauce. Its freshness lifts and complements the sauce’s flavor.

In simmered dishes and hot pots: When large amounts of grated daikon are added, the dish resembles sleet (a mix of rain and snow). These dishes are called mizore-ni (simmered with grated daikon) or mizore-nabe (hot pot with grated daikon). Variations used for side dishes are called mizore-ae. A hot pot generously topped with grated daikon looks beautiful, like a snowy landscape, and has a refreshing mouthfeel. It enhances the meat’s umami without feeling heavy. It pairs well with pork or chicken.

With noodles: Adding grated daikon radish to cold noodles creates a refreshing mouthfeel, perfect for hot weather. Incorporating it as a garnish also sharpens the overall taste.

As a condiment: Daikon oroshi is also enjoyed with Japanese-style hamburger steak and Japanese-style beef steak. It cuts through the richness of meat and aids digestion. A splash of ponzu or soy sauce transforms it into a distinctly Japanese flavor.

Beyond its culinary uses, the distinctive pungency of daikon oroshi also has a fascinating scientific basis. Let’s take a closer look.

What is the pungent component in daikon oroshi?

The pungent component in daikon oroshi comes from allyl isothiocyanate (a type of isothiocyanate) contained in the essential oil component mustard oil. Daikon radish itself is not spicy when eaten whole. However, grating or cutting the daikon breaks its cells, causing the precursor compounds of isothiocyanates within the cells to generate the pungent isothiocyanates. The tip of the daikon is spicier because it contains a higher concentration of these isothiocyanate precursors.

Why does the spiciness of Daikon oroshi disappear during cooking?

Daikon oroshi becomes sweeter when heated. This is the same principle as daikon becoming sweeter when simmered. The pungent isothiocyanate compounds are volatile, so they evaporate during heating. The glucose naturally present in the daikon remains, and this is what we perceive as sweetness.

The enzyme myrosinase is involved in converting the isothiocyanate precursors into the pungent isothiocyanates. Generally, enzymes are most active near neutral pH and do not function in acidic or alkaline conditions.

When cooking, adding vinegar to Daikon oroshi makes it acidic, deactivating myrosinase. Consequently, no isothiocyanates are produced, so it doesn’t taste spicy. When soy sauce is added to daikon oroshi, the areas touched by soy sauce are not spicy because only those parts become acidic, causing myrosinase activity to cease. Placing daikon oroshi into warm tempura dipping sauce warms the daikon oroshi, causing the isothiocyanates to volatilize and disappear. This results in a lack of spiciness, a refreshing texture, and allows the oily tempura to be enjoyed.

Why is wasabi always served with sushi and sashimi?

A photo of sashimi — Wasabi is always served alongside sashimi.

Wasabi, a vegetable native to Japan, is traditionally served with raw fish dishes such as sashimi. While it has antibacterial properties, its primary role is to enhance the flavor of the fish. Japan has numerous aromatic vegetables, including wasabi, ginger, myoga, green onions, and sansho pepper, among others. Each possesses a unique aroma and aromatic compounds. Adding these to other foods or mixing them during cooking stimulates the taste buds, significantly enhancing the flavor of the dish. Since all these aromatic vegetables have antibacterial and sterilizing effects, they are often served with sashimi and similar dishes.

The pungent flavors of these aromatic vegetables can be broadly categorized into three types: the sharp, stinging heat of wasabi; the fiery, burning heat of chili peppers; and the numbing, tingling heat of sansho peppers. Each type has different components responsible for its distinct heat. Let’s examine them individually.

The pungent component in wasabi is a substance called sinigrin. Sinigrin itself has no pungency, but when the cells are broken down by grinding or similar processes, exposing sinigrin to oxygen in the air causes the enzyme myrosinase to produce a substance called allyl isothiocyanate. This allyl isothiocyanate is the pungent component in wasabi and Leaf mustard or Mustard greens. Wasabi is a plant in the Brassicaceae family, and sinigrin is a substance widely found in vegetables of this family. The pungent taste in other Brassicaceae plants like Mustard cress or Daikon mustard also comes from sinigrin. Wasabi simply contains a particularly high amount of it.

There are two types of wasabi: Sawa wasabi and Yama wasabi. Sawa wasabi is the common, green variety you see most often. Yama wasabi, on the other hand, is the horseradish served with roast beef and similar dishes. Although both are wasabi, their shape and color are completely different. Yama wasabi resembles spicy radish and is used as the base for prepared wasabi paste and powdered wasabi. It has low moisture content and is large in size, resulting in a high yield, making it well-suited for processed products.

Wasabi has been consumed since the Heian period, with records indicating it was eaten mixed into dishes like grated yam broth. At that time, there seemed to be established rules: carp sashimi was served with wasabi vinegar, sea bream sashimi with ginger vinegar, and sea bass sashimi with tade vinegar. Given the era’s hygiene concerns, it’s likely a considerable amount of aromatic vegetables were used. Wasabi began to be eaten with soba noodles, now commonplace, around the Edo period. Originally, spicy radish was served alongside soba. However, when radish was unavailable, wasabi was substituted. It is said that wasabi became a staple because it masked the distinctive fishy odor of the bonito flakes in the soba dipping sauce. Generally, it’s hard to imagine wasabi replacing radish.

Next, when it comes to chili peppers in Japan, Takanotsume (Bird’s eye chili) and Shichimi togarashi (seven flavor chili pepper) are common. Bird’s eye chili is often added to preserved foods such as rice bran pickles, and it has also been traditionally kept for medicinal purposes. This is because Bird’s eye chili also has antibacterial properties. It offers significant health benefits, burning body fat, warming the body, opening pores, and promoting sweating. It is especially effective in winter for raising body temperature. In summer, eating spicy food induces sweating, allowing moisture to evaporate along with body heat, thereby lowering temperature. The capsaicin in Bird’s eye chili promotes fat breakdown and accelerates the breakdown of glycogen in the liver and muscles. Consequently, it not only stimulates the stomach and improves blood circulation but also activates digestive movements within the internal organs, boosting appetite. It is effective during winter when lack of exercise reduces appetite, and also combats summer fatigue-induced loss of appetite.

Chili peppers have also been widely used in preserved foods like pickles, miso, and tsukudani. Their intense pungency and antibacterial properties enhance the shelf life of ingredients, making them a cherished seasoning that supports Japanese dietary habits.

The numbing spiciness of sansho comes from a compound called sanshool. Sanshool increases gastric acid secretion, making it a perfect match for rich, fatty dishes like eel. It also contains an aromatic compound called diterpene, which boosts immunity and enhances antioxidant effects. The name “sansho” (山椒) itself comes from the mountain-scented fruit that is spicy like pepper. Sansho is known as Japanese pepper in English, making it an iconic spice of Japan.

Furthermore, sansho has been utilized in diverse dishes by selecting either the berries or leaves. It is also used in preserved foods like tsukudani and chirimen sansho, enhancing ingredient preservation through its refreshing aroma and antibacterial properties. Additionally, in ancient times, it was valued medicinally as the herbal remedy “Shokushō (蜀椒),” prized for its stomach-strengthening and anthelmintic effects.

In other words, the practice of always serving wasabi with sushi and sashimi is not merely a custom. It is a tradition born from the convergence of scientific reasons like sterilization and antibacterial properties, the culinary ingenuity of maximizing the umami of fish, and the wisdom cultivated by the Japanese people throughout history. Wasabi is more than just a condiment; it is passed down to modern dining tables as a “key component” that elevates the dish’s overall quality.

Sushi Rice Shapes Explained: Rice-Bale vs. Boat-Bottom Nigiri Styles

A photo of Boat-Bottom Nigiri Styles — The appearance of Boat-Bottom Nigiri Styles

There are several ways to shape sushi rice, and when you look at a finished piece of nigiri from the side, you may notice distinctive forms. These shapes not only influence appearance but can also affect how the sushi is perceived in taste, making them a surprisingly important element.

The most common style is the rice-bale shape (Kometawaragata). A rice bale, traditionally made of straw to store and transport rice, has a cylindrical form, and the sushi rice resembles this when viewed from the side. The bottom that rests on the plate is relatively flat, while the surface in contact with the topping has a gentle curve. This creates a natural harmony with the fish, especially with thinly sliced or oily toppings, making it a versatile and widely used shape.

Another, less common form is the boat-bottom shape (Funazokogata). Seen from the side, it looks like an inverted trapezoid, with the top wider than the base. Because the contact surface between rice and topping spreads out like a fan, it gives the topping firmness and presence. This makes it especially suitable for larger cuts of fish, allowing them to sit beautifully without losing their shape.

The process of forming nigiri is essentially the same for both. Whether it becomes rice-bale shaped or boat-bottom shaped depends on how the chef applies pressure with the fingers. Even pressure produces the rice-bale form, while adding more strength to the bottom creates the boat-bottom form.

There is no inherent superiority between the two. The difference lies simply in shape, not in the skill level of the chef. Understanding these subtle variations can add another layer of appreciation to enjoying sushi.

Many sushi chefs used the Jigamigata technique. The name comes from its resemblance to the paper used for folding fans when viewed from the side. Jigamigata is considered well-suited for nigiri with larger toppings. This may be because in the past, shari often weighed 15g or more, paired with larger pieces of sushi toppings. Nigiri styles can be divided into endless detail, so we’ll stop here.

It is worth noting that, in the culture of Edomae-style sushi, harmony with taste has traditionally been valued more than visual form. The focus has been on the integration of topping and rice and on how the nigiri dissolves in the mouth, rather than on perfect geometric shapes. Consequently, chefs’ training and cookbooks emphasize techniques to enhance flavor rather than the precise shape of the finished sushi. This is also why literature often discusses how to form sushi but rarely describes the final shape in detail.

What is the difference between Yushimo and Yakishimo?

A photo of Kinmedai yakishimozukuri — The appearance of Kinmedai yakishimozukuri. Only the skin is seared.

In Japanese cuisine, it is common for the same cooking method to have different names depending on the season or context, which often leads to confusion. A good example of this is the distinction between yushimo and yakishimo. While they are similar, they are not identical, and understanding the difference is important.

The word shimo (霜) literally means “frost.” In cooking, shimofuri refers to a preliminary treatment in which food is briefly exposed to heat—by pouring boiling water over it, dipping it in hot water, or lightly searing it—so that the surface turns white, resembling frost. It is suitable for fish with beautiful skin or fish that are delicious when eaten with the skin on.

It also refers to the preparation step, similar to kawasimo or yushimo, where the fish is briefly dipped in hot water to remove scales and bloodline before preparing Arani (粗煮) or kabutoyaki (兜煮).

Shimofuri technique removes odors, sliminess, and excess fat while sealing the ingredient’s umami. It also firms the flesh and adds elasticity.

Yushimo (湯霜) comes from yu (hot water) and shimo (frost). It is a type of shimofuri in which the surface of fish or meat is treated with boiling water, either by dipping it quickly into hot water or by pouring hot water over it. The food is then immediately cooled in ice water and the moisture is removed before further preparation. This method is also known as yubiki (湯引き).

When used for sashimi, it is called yushimozukuri (湯霜造り). In this preparation, hot water is poured over the skin side of a fish fillet to soften the skin, after which the fish is chilled, the moisture is removed, and it is sliced. The result is an elegant appearance, with curled skin that enhances both flavor and presentation.

The term yushimozukuri refers not only to the cooking technique itself but also to the sashimi dish prepared using that method.

Yakishimo (焼霜), on the other hand, comes from yaki (to grill) and shimo (frost). This method involves lightly searing the surface of fish or meat until it develops a touch of browning, then cooled in cold water. Like yushimo, it removes excess fat and odor, but it also imparts a subtle roasted aroma. When used for sashimi, it is called yakishimozukuri (焼霜造り). This preparation is widely applied to fish such as red seabream, chicken grunt, barracuda, largehead hairtail, blackthroat seaperch, daggertooth pike conger, yellowtail, Spanish mackerel, bonito, and mackerel.

Depending on the style, the fish may be seared while still in fillet form (saku), or after being cut into sashimi slices. Just like yushimozukuri, the term yakishimozukuri refers both to the cooking method itself and to the sashimi dish created through that method.

Additionally, kawashimozukuri (皮霜造り) refers to sashimi in which the skin has been blanched in boiling water or over an open flame. This technique is also called matsukawazukuri (松皮造り) because, when applied to fish such as sea bream, it creates a pattern that resembles pine bark (matsukawa means pine bark). It enhances the umami of the skin while eliminating any fishy odor. It has the same meaning as Shimofuri and Yushimo.

In short, both yushimo and yakishimo are forms of shimofuri. Yushimo uses boiling water, while yakishimo uses direct heat from searing. Though their purpose is similar, each creates a distinct flavor, texture, and visual appeal, showcasing the ingredient in a uniquely Japanese way.

What is the difference between Aburi and Tataki?

A photo of aburi — Grilling is more commonly done with meat than with sushi toppings.

Both Aburi and Tataki are Japanese cooking techniques that involve exposing food to high heat, but they differ in both purpose and process.

Aburi means “to sear,” and refers to lightly grilling the surface of food while leaving the inside raw.

In sushi, aburi is often applied to fatty cuts like salmon or tuna, where the flame enhances aroma, melts fat, and creates a contrast between the charred surface and the fresh interior. Some chefs use handheld gas burners, though Edomae-style masters often disapprove because of the faint odor left by the gas. For them, aburi is not about making the fish richer, but about controlling fat so the sushi remains balanced.

Other methods such as charcoal grilling, ovens, or iron plates can also be used, producing different aromas and textures. Aburi also appears in vegetables—like peppers or eggplants whose skins are charred and peeled—and in desserts such as crème brûlée or baked custard pudding, where caramelized surfaces are essential.

Tataki, in contrast, is more polysemous. In its seared form, tataki refers to quickly grilling the surface of fish or meat, then cooling it and slicing it.

Unlike aburi, tataki is always finished with seasonings: the slices are eaten with condiments such as soy sauce, ginger, garlic, or other pungent garnishes. This seasoning process is essential to the identity of tataki. The best-known example is katsuo no tataki from Kochi, where bonito is straw-seared, chilled in ice water, and served with generous amounts of aromatic condiments.

The term tataki also extends to finely chopping fish into a mince or even a paste, and to vegetables like cucumber or burdock root that are pounded to soften their texture, but in comparison with aburi, it is the seared and seasoned preparation that is most relevant.

Thus, while both techniques highlight the interplay of cooked and raw, aburi serves primarily as an aromatic finish that enhances natural flavor, whereas tataki is a preparation that combines searing with deliberate seasoning. This requirement of seasoning after searing marks a fundamental difference between the two.

What is the difference between Real and Imitation wasabi?

A photo of Imitaion wasabi — This is imitation wasabi served with uramaki.

When most people think of wasabi, they picture a bright green paste with a strong, nose-tingling heat. In reality, what is served in most sushi restaurants around the world—including in the U.S., Europe, Asia, and China—is usually imitation wasabi.

This is not because restaurants want to mislead customers, but because real wasabi is incredibly difficult to grow and very expensive. The Wasabia japonica plant needs pure spring water, cool temperatures, and several years of careful cultivation, which makes large-scale production nearly impossible. As a result, genuine wasabi is rare even in Japan, and much harder to find abroad.

A photo of Imitation wasabi — Imitation wasabi is a food product primarily made from horseradish. It contains added coloring, flavoring, and thickening agents that give it the appearance and taste of real wasabi.

Imitation wasabi, made from horseradish, mustard, and green coloring, became the practical solution. It is affordable, easy to store, and widely available, which has allowed sushi culture to spread and become popular worldwide. Without this substitute, sushi culture might not have grown as quickly outside Japan.

Even in Japan, most wasabi served at conveyor-belt sushi chains or sold in supermarkets is not 100% hon-wasabi (hon means real). There are powdered forms that must be mixed with water, and smooth pastes packaged in tubes. Their compositions vary: some include a small amount of domestically grown wasabi rhizome, others add mustard powder for extra sharpness, and many rely primarily on horseradish. In other words, “imitation wasabi” in Japan exists on a spectrum—from blends with real wasabi to products made almost entirely from substitutes.

By contrast, at high-end sushi restaurants and traditional ryotei in Japan, chefs freshly grate real wasabi rhizomes on sharkskin graters and serve it directly with sushi. These chefs deliberately choose authentic wasabi because it brings out the natural character of the fish and rice. Its fleeting heat, subtle sweetness, and refreshing aroma work in harmony with the sushi rather than overpowering it. In other words, real wasabi is not just a condiment—it is an essential element that allows the true flavor of the ingredients to shine.

In recent years, a few farms in the United States—in places like Oregon, North Carolina, and California—as well as in Europe, China, and other parts of Asia have begun cultivating real wasabi. However, the same challenges remain: it cannot be mass-produced, so supply is very limited.

So while most people around the world—and even many in Japan—have only encountered imitation wasabi, it exists for very practical reasons. And when diners finally taste freshly grated real wasabi, they often discover a surprisingly delicate, even slightly sweet flavor unlike anything they expected.

For travelers visiting Japan, tasting real wasabi at a sushi restaurant or ryotei is a unique culinary experience. It is an opportunity to appreciate the subtlety and harmony of authentic Japanese cuisine—something that cannot be fully replicated elsewhere.

The Birth of Edomae Sushi Through Soy Sauce

A photo of soy sauce — The main ingredients of soy sauce are soybeans, wheat, and salt.

The Deliciousness of Nigiri Sushi and the Role of Soy Sauce

The appeal of nigiri sushi lies in the balance between the vinegared rice

’s gentle acidity and the seafood’s natural umami. Soy sauce elevates this harmony, acting like a quiet but essential partner in the background—a supporting role without which sushi would feel incomplete.

So-called Kansai-style sushi, such as oshizushi, bozushi, and hakozushi, which developed from preserved foods, involves seasoning not only the vinegared rice but also the sushi toppings. Therefore, it can be eaten without soy sauce. However, Edomae sushi uses fresh ingredients and values the inherent flavor of those ingredients. This necessitated a soy sauce that wouldn’t compromise the natural taste of the ingredients but rather enhance it.

Soy sauce contributes more than taste. It also helps neutralize the fishy odor that vinegar alone cannot remove. For instance, in hikarimono like kohada, saba, and aji, even a light brush of soy sauce softens the smell and polishes the flavor.

Beyond flavor and aroma, soy sauce also plays a role in preservation. Just as vinegar and salt protect sushi from spoilage, soy sauce has long been recognized for its bacteriostatic properties. In this way, it supported the development of Japanese cuisine, which relies on raw ingredients even in Japan’s humid climate.

Whether through its color, taste, fragrance, or hygienic qualities, soy sauce is woven into the very foundation of Japanese culinary culture.

Traditional Soy Sauce in Edomae Sushi

Edomae sushi originally used seafood caught in Tokyo Bay, but from the Edo period onward, fish such as tuna were also brought in from distant waters. These were often marinated in soy sauce in a technique called zuke. The name itself comes from this marinade, and to this day, sushi shops that uphold Edomae traditions still serve maguro zuke. Thanks to modern freezing and storage methods, fresh tuna is available year-round, so zuke is no longer a necessity—but its deep, mellow flavor endures.

In the past, soy sauce was rougher and less refined than today. To suit their needs, sushi chefs would cook and season it, creating nikiri shoyu (“simmered soy sauce”). This is typically made by gently simmering soy sauce with 10–20% mirin, sometimes with sake, bonito stock, or water. After about 30 minutes, when bubbles form, the heat is turned off. The word nikiri—literally “simmered to completion”—is said to come from this step.

Although improvements in modern soy sauce mean some shops no longer use nikiri, many traditional Edomae sushi restaurants still brush it onto their nigiri, just as they continue the practice of zuke.

Among simmered toppings (nimono) like anago, shako, and hamaguri, another essential sauce is tsume (or nitsume). Made by reducing the simmering liquid of anago or hamaguri with soy sauce, mirin, and sugar until it becomes a rich glaze—about one-tenth its original volume—tsume has been perfected in each restaurant’s own style.

Traditionally, tsume is prepared when high-quality anago arrives. The head and bones are simmered to create a flavorful broth, which is strained and then combined with soy sauce, mirin, and sugar. It is slowly reduced over half a day into a glossy sauce. The choice of soy sauce here is critical, and many sushi chefs say that the depth of a restaurant’s tsume reflects its true character.

Conclusion

In sushi, soy sauce is far more than a condiment. It balances flavors, refines aromas, preserves freshness, and embodies tradition. The delicate ways in which it is used—through zuke, nikiri, or tsume—are a testament to the craft of Edomae sushi and remain central to the essence of sushi culture today.

What is Aka shari?

A photo of aka shari — This is nigiri sushi with aka shari.

The “aka” in aka shari means “red” in Japanese, while “shari” refers to the vinegared rice used in sushi. Literally, it means “red vinegared rice,” but it doesn’t actually refer to bright red rice; instead, it denotes vinegared rice with a slightly brownish hue.

Why is it called “red”?

Typical vinegared rice is made by mixing cooked white rice with rice vinegar or grain vinegar. These vinegars are clear or pale yellow and don’t significantly change the rice’s color. As a result, the general understanding worldwide is that vinegared rice is white. Occasionally, artificially colored vinegared rice—such as blue or purple varieties—can also be seen.

By contrast, aka shari is made with red vinegar or black vinegar. These are dark brown liquids, and when mixed with rice, they produce vinegared rice with a light brown tint. Red vinegar was traditionally used in Edomae sushi, which originated in the Edo period, and this practice gave rise to the term “aka shari.” Its opposite is “gin shari.” While “gin” means silver, in this context it refers to pure white sushi rice.

However, making sushi rice exclusively with red or black vinegar results in a color that is too dark and an aroma that is overpowering, leading to an unbalanced taste. Although these vinegars are rich in umami components like amino acids, using them alone disrupts the overall harmony and can be polarizing in flavor. For this reason, sushi chefs commonly blend them with rice vinegar or grain vinegar. In fact, vinegar producers even sell blended vinegars specifically designed for vinegared rice.

Just as with other fermented foods, not everyone appreciates the flavor of aka shari made with red or black vinegar. While some chefs use it to emphasize the traditional prestige of Edomae sushi, it doesn’t always suit sushi that relies on a refreshing acidity.

Summary

Aka shari refers to sushi rice made with red vinegar, a hallmark of Edomae sushi. Its distinctive flavor and color add depth, but it is challenging to handle and not to everyone’s taste. How red vinegar is blended with other vinegars, and how the final rice harmonizes with sushi as a whole—this is where the craftsmanship and philosophy of the sushi chef truly shine.

What is the difference between Sabazushi and Battera?

Both sabazushi and battera are types of oshizushi made with mackerel. Oshizushi is made by layering vinegared rice with vinegared mackerel and shiro-ita konbu, then pressing the mixture into a wooden mold. Mackerel has been abundant in Japan since ancient times, which led to the development of this dish as a practical preserved food.

There are clear differences between Sabazushi and Battera, so let us explain them.

A photo of sabazushi — The appearance of sabazushi

Sabazushi is said to have originated in the Edo period. Mackerel is salted and transported from its place of origin in Wakasa to Kyoto, where it arrives after 2 to 3 days, by which time the seasoning is just right. This salted mackerel is used to make Sabazushi. Even today, with the development of refrigeration technology, it remains popular with many people and is also a local dish of Kyoto. There are also long-established sushi restaurants that have been in business for generations. Additionally, Sabazushi can be found in other regions such as Hyogo, Hiroshima, and Wakayama, which have adopted the dish from Kyoto.

Sabazushi is prepared using a unique method. First, the air is removed from the vinegared rice to extend its shelf life. Then, the vinegar-marinated mackerel is formed into sticks with a cloth or bamboo mat. Finally, shiroita konbu or rausu konbu is placed on top to prevent the mackerel from drying out. Only half of the mackerel is used so that the thickness of the flesh is evident. The cross-section is rounded, which is why it is also called bozushi (bo means “stick”).

A photo of battera — The appearance of battera

Next, Battera is a type of Oshizushi made by placing thinly sliced mackerel marinated in vinegar and shiroita konbu simmered in sweet vinegar on top of vinegared rice. It is typically shaped using a square mold. The mackerel is cut with a knife to minimize waste, resulting in an almost uniform thickness.

Battera is said to have been invented in 1894 by Tsunekichi Naka, the founder of Sushi Tsune, a sushi restaurant in Osaka. At the time, Sushi Tsune was selling Oshizushi made with Konishiro (Gizzard Shad), which was commonly caught in Osaka Bay. Due to its popularity, the traditional method using a cloth became insufficient for production, so a wooden, boat-shaped mold was used instead.

Customers reportedly referred to the mold as “bateira,” a Portuguese word meaning “boat,” which evolved into “battella.” Over time, this name further transformed into “Battera.” As the price of Konishiro (Gizzard Shad) rose, mackerel was adopted as an alternative, and due to its ease of shaping, square molds became the standard.

In summary,

Sabazushi: Use a bamboo mat to shape the fish into a round form, using thick slices of mackerel left whole. The cross-section has a rounded shape.

Battera: Shaped into a square using a wooden mold, thinly sliced mackerel is arranged evenly. The cross-section is square.

Sabazushi is a traditional regional sushi centered around Kyoto, while Battera is a type of sushi that became popular among the general public in Osaka.

What is the difference between Chirashizushi and Barachirashizushi?

A photo of chirasihizushi — This is what most people think of when they hear the word chirashizushi.

Recently, I came across an image on social media of Barachirashizushi made by an American sushi chef. I was surprised to see that Barachirashizushi, a dish traditionally made only by a few sushi restaurants that uphold the Edomae-style, had been created by a sushi chef outside Japan. However, it was labeled as Chirashizushi, which I found disappointing, so I will explain the difference.

The term “chirashizushi” (or “chirashi sushi”) originates from the act of scattering various ingredients over or within vinegared rice and is sometimes referred to simply as “chirashi.” Generally, “Gomokuzushi” refers to vinegared rice mixed with ingredients, while “chirashizushi” refers to vinegared rice topped with arranged ingredients. However, these terms are not strictly distinguished. The names may vary depending on the region (e.g., Kanto or Kansai) and generation.

First, let’s explore the origin of chirashizushi. The term “barazushi” appears here, but it is different from barachirashizushi.

Barazushi, a type of sushi from Okayama, is said to date back to the early Edo period. At that time, the feudal lord of Okayama Domain, Ikeda Mitsumasa (1609–1682), promoted frugality and simplicity. He issued the “One Soup, One Side Dish Edict,” which restricted side dishes to one item other than soup.

They finely chopped ingredients such as simmered shiitake mushrooms, kanpyo (dried gourd strips), and carrots and secretly mixed them into the rice. According to one story, sushi ingredients were placed at the bottom of a box and covered with seasoned rice to disguise them as a simple meal. The box was then flipped over just before serving.

As “Barazushi” spread throughout Japan, a style of scattering the ingredients on top of the vinegared rice rather than mixing them in was developed, and this became known as “Chirashizushi.”

Now, let’s look at the difference between chirashizushi and barachirashizushi, focusing on the names used in sushi restaurants in Tokyo.

a photo of Chirashizushi — The appearance of Chirashizushi

In Tokyo sushi, specifically Edomae sushi, Chirasushizushi refers to a dish where sushi toppings used for Nigiri sushi are arranged on top of vinegared rice (also known as Namachirashi, Fukiyosechirashi, or Edomaechirashi). However, in regions outside the Tokyo area, Chirashizushi generally refers to a dish where seasoned ingredients are mixed into vinegared rice and decorated with shredded omelette and seaweed (also known as Gomokuzushi or Barazsuhi). This is just my personal opinion, but I think that even in Tokyo, the latter is called chirashizushi.

Dishes made with plain white rice rather than vinegared rice are generally called seafood bowls. Sushi restaurants do not serve bowls of plain white rice (they cannot), but some restaurants call dishes made with vinegared rice seafood bowls. In my personal opinion, most seafood bowls served outside of sushi restaurants are made with plain white rice.

A photo of Barachirashizushi — The appearance of Barachirashizushi

Additionally, a dish with randomly arranged sushi toppings on vinegared rice is called “barachirashizushi.” Some traditional sushi restaurants in Tokyo offer two types: chirashizushi, which is primarily served in-store, and barachirashizushi, which excludes toppings that are not suitable for takeout and can be taken home.

Incidentally, chirashizushi made with sushi ingredients is not typically prepared in Kanto-style households. More precisely, it may include decorative toppings such as ikura (salmon roe), tobiko (flying fish roe), and steamed shrimp; however, the standard ingredients are dried shiitake mushrooms, lotus root, carrots, snow peas, and shredded omelet.

Similarities and Differences Between Karei and Hirame

What is Karei?

What is Hirame?

Conclusion

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Let’s take this opportunity to reexamine what truly constitutes the perfect time to enjoy food at its most flavorful.

First, let’s confirm where chutoro and otoro are located on the tuna using a cross-section diagram of the fish’s midsection.

Next, when the tuna is dissected, as shown in the illustration below.

Now, let’s get to the main topic.

The question then arises: where exactly is the boundary between otoro and chutoro?

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First, let’s look at the meanings of the words.

About Daikon

About Daikon Oroshi

Role and Uses of Daikon Oroshi

Popular ways to enjoy daikon oroshi include:

Beyond its culinary uses, the distinctive pungency of daikon oroshi also has a fascinating scientific basis. Let’s take a closer look.

What is the pungent component in daikon oroshi?

Why does the spiciness of Daikon oroshi disappear during cooking?

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The Deliciousness of Nigiri Sushi and the Role of Soy Sauce

Traditional Soy Sauce in Edomae Sushi

Conclusion

Why is it called “red”?

Summary

There are clear differences between Sabazushi and Battera, so let us explain them.

In summary,

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