Discover the Silent Star of Japanese Cuisine: Katsuobushi
This secret ingredient to most Japanese traditional dishes is produced en masse in Kagoshima
Washoku — traditional Japanese cuisine — has seen its profile skyrocket in recent years, even being registered as part of the world’s intangible cultural heritage by UNESCO in 2013. While delicate flavors, a focus on seasonal ingredients and stunning presentation receive massive praise, the workhorse behind the scenes is katsuobushi, dried skipjack tuna (katsuo in Japanese) that is flaked and used to make the dashi soup stock that forms the basis of many dishes.
Unlike many of Japan’s most famous foods which find their roots in ancient China, katsuobushi is a Japanese original, one that has been a part of the country’s culinary culture for more than 1,000 years. Originally, it was sundried before flaking, but since the 15th century, katsuobushi has been smoke-dried, and in some cases mold-fermented as well.
The end product is a hard-as-rock block of fish resembling driftwood whose savory secret is released only by shaving. In years gone by, shopkeepers would shave flakes of fish — called kezuri-bushi — to order, but unfortunately, flakes degrade quickly once exposed to air, losing their aroma and flavor. By the end of the 19th century, the problem of deteriorating flakes was solved with the invention of the katsuobushi-kezuriki, a mandoline-type device mounted on a wooden box that allowed families to shave their own flakes.
Thanks to technological innovations dating to the 1970s, katsuobushi is now flaked, packaged and sold in shops, flavor and aroma intact. However, those who value a more authentic flavor still favor flakes shaved the old-fashioned way.
Katsuobushi is not an easy product to process. Not only do traditional methods require a high level of skill, they are incredibly time-consuming, taking anywhere from several weeks for regular-grade katsuobushi, called arabushi, to upwards of six months for high-grade, mold-fermented katsuobushi, called honkarebushi. As a result, most manufacturing companies have made the switch to mechanization.
There are still a few locations where traditional techniques remain king, however, with Kagoshima, Japan’s top producer of katsuobushi, being home to many of those traditional operations. In the southern Kagoshima port cities of Makurazaki and Ibusuki—the Yamagawa neighborhood in particular—where 70 percent of domestically produced katsuobushi is made, you’ll find some of Japan’s most skilled katsuobushi craftspeople.
Skipjack tuna is caught either off the coast of Japan or in seas around the equator. Once brought to shore and thawed, each tuna is hand-filleted and quartered, then simmered in water over 90 degrees Celsius for between one and two hours.
Post hot-water dip, the fish are painstakingly deboned by hand. Should even one bone remain, the drying fish will warp and be ruined. For tuna destined to become high-grade honkarebushi, holes left in the flesh by the removal of bones are filled in with fish paste for a smooth finish.
After de-boning, the tuna is placed on racks for drying in a large, multistoried smoking room heated with hardwood fires. This process takes several weeks and involves intervals of smoke-drying and cooling, which allows moisture deep within the fish to make its way to the surface for uniform drying throughout. Smoke-drying the skipjack tuna also ups the umami for a more savory flavor.
At the end of this process, the tuna has become arabushi, the regular grade of katsuobushi. The majority of the arabushi is finished and ready for flaking, but the small number of fish quarters predestined for honkarebushi still have to be mold-fermented. The process is a relatively recent innovation in katsuobushi production, and it is said that it began with the accidental discovery that mold not only improved the flavor but also removed the fishy smell.
Mold-fermenting begins with blocks of arabushi being lightly shaved to remove any surface fat. They are then sprayed with mold and placed in a warm, humid room to mature before being removed for sun-drying. This process is repeated for three to five months. By the end, the pieces of arabushi have become honkarebushi. Covered in a dusky beige film, honkarebushi must be scrubbed with a stiff brush before being used.
As a basic ingredient in Japanese cooking, katsuobushi is omnipresent. When used to make dashi soup stock, it finds its way into miso soup, broth for udon and soba, and multiple other dishes with a soup base.
As a simple flake, katsuobushi adds an umami boost to rice, chilled tofu, blanched greens and broccoli, natto fermented beans and all manner of meals where it’s used as a garnish. It gets stuffed into onigiri rice balls and sprinkled over noodles and okonomiyaki savory pancakes, as well as takoyaki, the famed Japanese street food.
Add anywhere from a light sprinkling to a heaping handful of flakes to any savory food for added oomph. Or, to enjoy katsuobushi the Kagoshima way, place a dollop of miso and a handful of flakes into a bowl and pour on some green tea for a dish known as chabushi.
Since katsuobushi is intrinsic to Japanese cuisine, you’ve almost certainly already tried it. But if you find yourself in Kagoshima, it’s worth your while to go out of your way to savor the country’s finest.
If in the city, pick up high-quality katsuobushi in all manner of forms at Marutoshi’s Ogawa-cho shop, located near Kagoshima Station just off Sakurajima Sambashi-dori. Or, travel to the source, visiting Makurazaki or Yamagawa, Ibusuki. At Makurazaki Fish Center, you’ll find katsuobushi for sale, as well as shaving demonstrations and the chance to try chabushi. The second-floor restaurant offers items made with katsuobushi as well.
Savor Ibusuki Katsubushi Ramen, an Ibusuki specialty of noodles served in honkarebushi broth and topped with honkarebushi flakes, at Roadside Station Yamagawa Minato Io-Kaido in Yamagawa, Ibusuki. You’ll also find soba and udon served in katsuobushi-based soup and locally produced honkarebushi for sale.
Katsuobushi, like washoku in general, is picking up steam abroad — there are even Japanese-run manufacturing plants in Europe producing the staple. Stock up while in Kagoshima, but don’t be surprised if you soon start seeing katsuobushi flakes on store shelves in your home country, too.
Marutoshi: 14-5 Ogawacho, Kagoshima, 892-0817
Roadside Station Yamagawa Minato Io-kaido: 1-10 Yamagawa Kinseicho, Ibusuki, Kagoshima 891-0506
Makurazaki Fish Center: 33-1 Matsuno-cho, Makurazaki, Kagoshima 898-0001