What is Katsuobushi?
Katsuobushi, the most important ingredient in dashi at Japanese cuisine
Katsuobushi is made of katsuo or bonito, skipjack tuna, a saltwater fish. Bonito is rich in protein. If unprocessed, it has a 25% protein content, and if used to make katsuobushi, its proteincontent increases to 77%. It is also rich in inosinate, an important umami substance; the umami is multiplied many times over when combined with glutamate.
This is the mechanism behind ichiban dashi (“first soup stock”) in Japanese cuisine.
Katsuobushi is not just about smoking fish; the creation process is a tradition that has been handed down for over nearly 400 years. Making katsuobushi involves drying katsuo, introducingbeneficial mold that triggers fermentation, and creating a deeper, richer flavor. The process takes many months, and the end result is a surprisingly hard, richly flavorful food product. The finished katsuobushi is shavedusing a box grater.
The resulting flakes are used mainly for making dashi (stock). This method can use other kinds of fish, such as tuna, mackerel, and sardine.
The Making of Katsuobushi
The process of making katsuobushi begins with filleting fresh bonito (skipjack tuna) into three pieces referred to as kame bushi (“turtle block”). The large piece is then further split into twohalves—called mebushi (belly) and obushi (back)—that make up the honbushi (“main block”). The blocks are placed in a woven tray in hot water, carefully arranged to ensure uniform flavor in the end product, and simmered for 60to 90 min in a step known as shajuku, sealing in the inosinate. The skin and bones are then removed. The blocks are called namaribushi at this point. The next step is baikan (“smoke-drying”). The namaribushi undergo prolongedsmoking to remove water content and prevent spoilage. After the first round of baikan, the cracks and cavities are repaired using a paste made from the head and nakaochi (tuna scrape), followed by over a dozen more rounds ofbaikan to remove even more water, kill harmful bacteria and prevent them from taking hold, and block oxidation. The baikan process transforms the namaribushi into arabushi.
Honkarebushi, a higher grade of katsuobushi, is made by putting the arabushi through a process known as kabitsuke (“mold application”). A coating of beneficial mold seals in aroma. The sporesdraw out the last of the moisture from deep inside the block; they also break down triglycerides, giving clarity to any soup stock eventually made from that honkarebushi. Around 2 weeks later, the block is temporarily removedfrom its tub, sun-dried, and individually dusted to remove the surface mold. These steps are repeated for around 4 months. It is through this long-drying process that katsuobushi, known as the hardest food in the world, iscreated.
Katsuobushi and Inosinate
Katsuobushi contains extremely high levels of the umami substance inosinate. In fact, the baikan and kabitsuke processes boost the inosinate level over what is found in fresh bonito. Shavingkatsuobushi using the box grater increases the surface area and makes it easier to prepare stock. The paper-thin shavings also allow inosinate, which dissolves easily in water, to be quickly extracted while preventing other,less dissolvable amino acids from releasing their flavor or clouding the stock.
Katsuobushi and Dashi
Katsuobushi is shaved using a box grater before being used to prepare stock. The simple, rich dashi made from unfermented arabushi is also a popular part of Kansai cuisine. The obushi (back) ofhonkarebushi produces refined stock low in fat, whereas the mebushi (belly) yields a dashi with more richness. Ichiban dashi (first stock) made from a combination of glutamine-rich kelp and inosinate-rich katsuobushirepresents a cooking method that makes the most effective use of umami synergy. This is why ichiban dashi is the bedrock of Japanese cuisine. High-end establishments, such as a ryōtei, will also use magurobushi (bluefin tuna)at times instead of katsuobushi, for a dashi with a refined and clean flavor.
Dashi most commonly utilizes a combination of kombu (kelp seaweed) and katsuobushi (dried bonito flakes), but other ingredients used to make dashi are shiitake mushrooms and niboshi (small driedfish). Dashi-making has evolved over a long period of time. Boiling is known to have been used in Japanese cooking since the Jomon period (c. 13,000–300BC), and the stock from shellfish and fish-bones was used to flavor otherdishes.
What is Dashi?
Umami Synergy in Ichiban Dashi
Ichiban dashi (first brewed) is made by adding lots of katsuobushi to kombu dashi when it comes to a boil. Ichiban dashi is then strained using a strainer covered with a thin clothon top. Although katsuobushi is added to kombu dashi for only a few minutes, the umami taste of ichiban dashi is more pronounced than that of kombu dashi. The fragrance of katsuobushi then increases. Inosinate is a keysubstance in the umami taste of katsuobushi. Moreover, the umami taste of dashi is greatly enhanced when the glutamate found in kombu meets the inosinate of katsuobushi. Adding katsuobushi to kombu certainly has awonderful synergic effect.
Japanese Cuisine with Delicious Umami
By the seventh century, a dashi using kombu and katsuobushi had developed. This was refined further and has become Japan’s most indispensable cooking stock, generally used in two forms – ichiban(primary) dashi and niban (secondary) dashi. Despite its hidden role, dashi could be said to be the heart of Japanese cuisine, not because of the prominence of its own flavor but because of the way it enhances and harmonizesthe flavors of other ingredients. The secret of Japanese cuisine is the art of enhancing and harmonizing.
A great variety of fresh food ingredients is available in Japan, with its regional diversity, clearly differentiated seasons, and fertile soil. Washoku, Japanese cuisine, has a tradition ofcherishing each season. With umami, chefs bring out the flavors of those seasonal ingredients. Keeping to tradition, they devote themselves to innovation. Please enjoy their umami dishes.
Umami in Washoku
What is Umami?
Umami is the fifth taste, joining sweet, sour, salty and bitter. These are unique tastes that cannot be created by mixing other tastes, and are known as the basic, or primary tastes. Umami is ageneral term used mainly for substances combining the amino acid glutamate, and/or the nucleotides inosinate and guanylate, with minerals such as sodium and potassium.
Whether something tastes good or not is a comprehensive yet subjective evaluation determined by elements such as taste, aroma, texture and temperature, besides other factors such as appearance,color and shape, as well as one’s physical condition, surrounding environment, cultural background, and previous experiences. Of these various elements, umami in balance with the other basic tastes (sweet, sour, salty, andbitter) plays an important role in determining the deliciousness of a dish.
What is Umami
