Katsuobushi

LEARNING ABOUT KATSUOBUSHI

Your Japanese grocery store Nishikidôri tells you everything

What is katsuobushi?

"Katsuobushi" is the common name for smoked and dried bonito. Katsuobushi has several by-products with different names, depending on the stages and degree of the processing.

Bonito (Katsuwonus pelamis) that has been boiled, smoked, and dried is known as arabushi. When the surface of arabushi is planned and trimmed to improve its shape, it is called hadakabushi. If a mold (microscopic fungus) is then grown on the hadakabushi, twice or more, it is called karebushi.

The general term for all these products is katsuobushi.

Did you know that?

Since December 2013, Washoku, or traditional Japanese cuisine is part of the Intangible Cultural Heritage of Humanity of UNESCO. This news was welcomed with joy in Japan.

What comes to mind when you hear the term Washoku, or Japanese food? Things like sushi, sukiyaki, tempura, soba, and udon perhaps. Or it could be that a dish you are used to eating is an arranged version of Japanese food that has passed through your country after being adapted to local taste.

Today, Washoku, the traditional Japanese food, is enjoyed all over the world. It is not an exaggeration to say that the secret of Washoku taste is the dashi (which means soup broth). Dashi is the basis of Washoku. Western cuisine has its own broth, fond.

The Washoku equivalent is dashi (soup broth) prepared with ingredients like katsuobushi (smoked and dried bonito) and kombu (dried seaweed). Today, everyone can consume a wide range of food from all over the world and is confronted with a wealth of information on a wide variety of products. Therefore, in proselytizing Washoku, Japan has a responsibility to provide accurate information about the dashi used in Washoku and its taste. The basis of Washoku is dashi and the most popular type of dashi is katsuobushi dashi (dashi made with katsuobushi).

For centuries, and right up to the present day, the Japanese have developed their unique culinary culture around fish, especially katsuobushi, which is made by simmering bonito in hot water, then smoking and drying it.

It has long been a favorite ingredient of the Japanese because of its delicious taste and good preservation.

Katsuobushi and Katsuobushi dashi: why do the Japanese love them?

Japan is an island blessed with abundant nature. The Japanese people developed mainly as farmers working the land and harvesting the fruits of the mountains, rivers and ocean.

They became great lovers of a wide variety of fish and shellfish, a vital source of protein.

During this history of the development of culinary culture, the Japanese have formed and evolved their fish-eating culture, from the wide variety of preparation methods such as grilling or stewing, to the wide variety of products such as dried fish and fish paste. During this historical process, the Japanese tried various methods of using katsuobushi to prepare dashi, and katsuobushi became the key ingredient for dashi.

What is believed to be the early form of katsuobushi is mentioned in Japan's oldest historical chronicle, the Kojiki (Chronicle of Ancient Facts) of the year 712.

At that time, katsuobushi was a valuable commodity used to pay taxes in kind because it was known to be long-lasting. However, its production method was probably very simple at that time; simply simmered in hot water and then dried in the sun.

Later, in the Samurai era, it is reported that Samurai soldiers used to carry and eat katsuobushi just like that; it was their ration on the battlefield.

Around 1600, there was a change in the method of producing katsuobushi. The traditional sun-drying was replaced by smoking over a wood fire, a process that is now called arabushi. Then, around 1800, the technique of producing karebushi is thought to have emerged when it was discovered that cultivating a mushroom of the genus Eurotium on the arabushi improved its taste. This is how katsuobushi became the unique Japanese ingredient.

Having become a classic ingredient for dashi used in Japanese cuisine, katsuobushi played an important role in the development of many local varieties of cuisine that emerged during the flourishing Edo period (1600-1868). In addition, culturally, it was used as an offering to the gods. As a result, it was considered an auspicious gift and a wedding present, becoming an integral part of Japanese life and customs.

Katsuobushi and Umami

Along with sweet, salty, sour, and bitter, the fifth category of taste is Umami, which Japanese scientists were the first to identify in the world. Today Umami is widely recognized as a common taste in the world.

Glutamic acid, an amino acid substance classified as Umami, was discovered in kombu (dried seaweed) in 1903; then inosinic acid, a nucleotide acid substance classified as Umami, was identified in katsuobushi in 1913; both by Japanese scientists. In 1960 it was discovered that awase dashi (mixed dashi), made from a mixture of katsuobushi and kombu (dried seaweed), further intensified Umami through the interaction of the inosinic acid in katsuobushi with the glutamic acid in kombu. It is now known that the full use of this powerful Umami can improve the taste of food even with a little salt. Thus, one of the reasons for the Japanese predilection for katsuobushi dashi has been scientifically verified.

Does the production reserved for export have the same organoleptic qualities as the one dedicated to the Japanese domestic market?

The product is different because the smoky notes are much less pronounced. The product is finer, more subtle, more elegant, and less acidic. However, it is perfectly-recognized by many Japanese chefs, who are very surprised by the result obtained.

The product is healthier because it is not saturated with benzopyrene residues or covered with Eurotium mold.

In Western cuisine, its use will be easier because the smoky notes and the powerful notes of bonito are replaced by more delicate accents accessible to all.

Is it a constraining product in terms of logistics?

The Japanese Katsuobushi benefits from controlled refrigerated logistics, by sea, and by air. The product requires temperature-controlled logistics not exceeding 5°C for long-term transport. It is stored in a cold room in France but can be shipped at room temperature to professionals if the delivery time is less than 5 days. However, it is recommended that it be stored in the refrigerator.

Quantities are limited for the time being.

What are the possible culinary applications of this bonito in pieces compared to the bonito in strips?

The applications are exactly the same, it will simply be necessary to acquire a grater to make the shavings (a professional quality grater is long-lasting).

It is important to respect the 60 degrees of inclination of the katsuobushi block to optimize the piece and not to grate by positioning the piece flat on the grater.

Katsuobushi and health

Katsuobushi is very rich in nutritional values. 20% of the human body is composed of amino acids (proteins). Amino acids are essential for muscles, vital organs, bones, nerves, blood, and skin... 9 of the 20 kinds of amino acids are not produced by the human body and must be provided by food. What is extraordinary is that katsuobushi contains, in a balanced way, all these 9 essential amino acids.

Moreover, it is very rich in docosahexaenoic acid, or DHA, necessary for the development and the cerebral memory, and in eicosapentaenoic acid or EPA recognized to prevent thrombosis (phlebitis, blood clot...).

Typical katsuobushi production process

The production process of katsuobushi is complex and time-consuming. It takes about a month to produce Arabushi and two to six months to finish the fermented version of karebushi. Although modern production equipment has been partially adopted, and productivity and hygiene have been improved, the basic process remains unchanged from ancient times.

Katsuobushi is prepared by skilled craftsmen who take great pride and confidence in their production of this traditional ingredient that has played a key role in sustaining the culinary culture of Japan. Today most katsuobushi is produced in Makurazaki City and Yamagawa District of Ibusuki City (both in Kagoshima Prefecture on the southern island of Kyushu) and in Yaizu (in Shizuoka Prefecture, south of Tokyo).

Description of the typical stages of katsuobushi production 

• Step 1: Cutting (Namagiri)

First, cut the heads and gut the bonito.

• Step 2: Cooking (Shajuku)

Boil the fillets for about one hour in water at 85-95°C. This process deactivates the enzymes in the flesh, prevents decomposition, and coagulates the proteins.

• Step 3: Cleaning (Honenuki)

Remove bones, fins, and scales.

• Step 4: Smoking (Baikan)

The next step is to repeat the smoking of the boiled and cleaned bonito fillets over a wood fire until the moisture content drops to no less than 26%. The resulting product is arabushi, a very aromatic smoked food.

When making Karebushi, the surface of the arabushi is first planned and the beneficial mold is cultivated two or more times (Kabitsuke process). The resulting product is called Karebushi.

As the above production process indicates, katsuobushi is a 100% bonito product and nothing else. Its difference from other smoked products is that there is no salt, condiment, or preservative added to its production.

The advantages of the smoking process

The repeated smoking of bonito after cooking in simmering water gives a very special aroma to katsuobushi.

In addition, the phenolic substances contained in the smoke prevent the oxidation of the fats. Fish fats oxidize particularly quickly and are susceptible to degradation. Unless dried by smoking, bonito fillets would deteriorate quickly and never acquire the pleasant taste of katsuobushi.

The important role of mold (microscopic fungus)

The mold culture process plays a major role in determining the taste of Karebushi. During this step, a mold of the genus Eurotium, selected for its remarkable qualities, is cultivated, which serves to further reduce the moisture still contained in the katsuobushi after drying and smoking. In addition, the lipolytic enzymes in the mold break down the fat in the fillets, making the dashi more transparent.

The etymology of the word katsuobushi

Firstly, fish dried by smoking is usually called "Fushi".

Secondly, bonito is called "Katsuo".

Perhaps you are beginning to understand since smoked and dried fish (Fushi) is made with bonito (Katsuo), hence the Japanese name katsuobushi (Katsuo + Fushi; the combination of the two words slightly changes the pronunciation).

Proper storage necessary to preserve the taste

When you buy katsuobushi and want to keep it for a long time, you should take the precaution of protecting it from mold (different from beneficial mold) and insects. Katsuobushi should be kept in the refrigerator in a vacuum-sealed package.

When you buy Kezuribushi (fine shavings of katsuobushi) and the bag has been opened, you have to close it tightly by vacuum and put it in the refrigerator. If the bag is small, it is recommended to consume it all at once.

The problem is that if you keep katsuobushi or a bag of Kezuribushi open, the katsuobushi will oxidize in contact with the air and its aroma will deteriorate. You have to take care of it!

How to use katsuobushi?

Katsuobushi is used in various forms in Japanese cuisine. In the past, in Japan, people used to buy katsuobushi in a store and grate it themselves at home before using it as an ingredient for dashi and cooked dishes. But times have changed. Today katsuobushi can be found in various convenient forms. The first is in the form of shavings. This version of shaved katsuobushi packaged in bags is sold in typical Japanese food stores, under the name Kezuribushi (which means shaved katsuobushi). Therefore, now people do not need to grate katsuobushi to prepare katsuobushi dashi. Kezuribushi comes in a wide range of thicknesses, shapes, sizes and quantities depending on the purpose of use, so consumers can choose the variety that suits their needs.

There are also other convenient products for preparing katsuobushi dashi. There is the powder, which is a powdered condiment, i.e., instant katsuobushi dashi prepared with pulverized katsuobushi. There is also the liquid condiment prepared with katsuobushi dashi, for noodle soup.

The use of these varieties of products makes katsuobushi dashi present in many Japanese dishes. For example, it is used in Japanese noodle soups such as Soba, Udon, Somen, and Ramen; it is used as a base stock for soups such as Miso soup as well as Nimono (simmering dish) and Nabe (Japanese style stew); it is present as a key ingredient in Tamagoyaki (Japanese-style omelette), Chawanmushi (steamed custard), Okonomiyaki (Japanese savory pancake containing a variety of ingredients), and Takoyaki (octopus’ dumplings).

How to prepare katsuobushi dashi?

The indications given below are for the preparation of dashi with Kezuribushi (katsuobushi in fine chips).

Have on hand 30 grs of Kezuribushi and 1L of water.

1. Bring to boil 1L of water in a saucepan.
2. Put 30 grs* of Kezuribushi in the pan.

Turn off the heat immediately.

*The recommended ratio is 3-4 parts of Kezuribushi to 100 parts of water.

3. The Kezuribushi will quickly fall to the bottom of the pan. When it is done, strain the liquid through a cloth or a sieve.

You now have the delicious dashi.

How to make awase dashi with a mixture of katsuobushi and kombu (dried seaweed)

The instructions given below are for making awase dashi (mixed dashi) with katsuobushi and kombu (dried seaweed). Have on hand 30 grs of Kezuribushi (= thin shavings of katsuobushi), 10 grs of kombu, and 1L of water.

1. Start by wiping off any dirt on the surface of the kombu with a clean soft cloth. Put the kombu in a pan and pour the water over it.
2. Put the pot on low heat and heat the water and kombu gently. Just before the water starts to boil, remove the kombu from the pot.
3. Put the Kezuribushi (fine shavings of Katsuobushi) in the same pot. Turn off the heat and wait for the Kezuribushi to fall to the bottom. When it's done, strain the liquid through linguine or a chinois. You now have the delicious dashi.

Using the Kezuribushi you can quickly prepare the delicious katsuobushi dashi which is the basic broth used in Japanese cooking such as Nimono (simmered vegetables) and Nabe (Japanese stew). By adding shoyu (soy sauce), mirin (sweet sake seasoning), and sugar to katsuobushi dashi you will get a good soup for soba noodles. In addition, you can enhance the flavors of the dashi by mixing katsuobushi dashi with other smoked and dried fish dashi such as Saba (mackerel) or Soudagatsuo (auxid).

Using katsuobushi as a garnish

Besides using dashi katsuobushi in cooking, another common use of katsuobushi is to sprinkle kezuribushi as a garnish on food. Have you ever seen video footage of "Dancing katsuobushi" on Japanese ready-made foods such as Takoyaki (octopus’ dumplings) or Okonomiyaki (Japanese savory pancake containing a variety of ingredients)? The Kezuribushi expands and contracts under the influence of the hot steam of the food so that it looks like it is dancing, hence the name "Dancing katsuobushi". Needless to say, the use of katsuobushi as a garnish is not limited to the garnish of Takoyaki and Okonomiyaki. Some dishes are served with thin slices of richly flavored Arabushi or sprinkled with exquisitely sweet Karebushi.

Today the use of katsuobushi extends beyond Japanese cuisine. Japanese chefs are taking up the challenge of using katsuobushi for non-Japanese dishes, each following their own inspiration. At the most basic level, seeing how it pleases the Japanese palate, it is sure that katsuobushi is an indispensable ingredient in their cupboard.

Some final observations

Katsuobushi is a traditional Japanese ingredient essential to Washoku. Despite the modernization of the production process through mechanization, it is recognized that the skills of individual craftsmen based on traditional technique, in addition to what machines do, play a key role in ensuring the quality of katsuobushi.

When exporting food products from Japan to another country or vice versa, it is necessary to comply with the laws of each country, including those concerning hygiene. As traditional Japanese Washoku cuisine spreads around the world, companies involved in the katsuobushi industry in Japan make every effort to ensure that the products delivered meet the standards of the export (destination) market.

Every country has its own traditional foods, and for each of these foods, there is a handcrafted production method unlike any other. As there have been advances in automation and health considerations have developed in modern times, some of these artisanal methods of producing typical foods may have been forgotten. Nevertheless, to fully understand a country, it remains essential to respect and honor the typical foods of that country as part of the overall culinary culture that the local geography and climate have fostered.

Katsuobushi has contributed greatly to the evolution of Japan's culinary culture and the Japanese predilection for this ingredient will certainly continue unabated in the future. Companies in the katsuobushi industry in Japan are now engaged in the next step of sharing the appeal of katsuobushi with people around the world and making people love katsuobushi more than ever.

Why does katsuobushi move?

The katsuobushi in shavings (Kezuribushi) placed on a hot dish as a garnish, will under the effect of heat start to dance. You can find videos of this phenomenon under the name "Dancing katsuobushi".

How to use katsuobushi? link: how to use it?

The katsuobushi can be used in two ways:

- For the preparation of a dashi

- As a garnish on a hot dish

How to replace katsuobushi?

You can replace katsuobushi with shiitake mushrooms or kombu seaweed.

Kombu can be grilled and crushed for use as a topping on noodles, tofu and vegetables.

Shiitake mushrooms can be used in place of katsuobushi to make a dashi broth. The goal is to offer a vegetarian dashi broth.

Where to find dried bonito Katsuobushi?

You can find Katsuobushi dried bonito on the website of your Japanese grocery store Nishikidôri in flakes or pieces.

• Katsuobushi of Yaizu in pieces
• Kezuri katsuobushi flakes
• Kezuri katsuobushi petals