Winter is the season for “kanburi,” fat wild yellowtail migrating south from the rich feeding grounds of the northern Sea of Japan.
Steaks of the oily winter yellowtail are sold for grilling with teriyaki sauce. Trimmings, such as belly and tail-end pieces can be put into a “buri oden,” a one-pot winter dish consisting of boiled eggs, daikon, konjac, and processed fishcakes stewed in a light, soy-flavored dashi broth. “Buri-kama” is grilled yellowtail collar. While “kanburi” can be served as sushi or sashimi, its oils make “ponzu” (a mixture of soy sauce, citrus and vinegar), a better compliment than the usual soy sauce and wasabi.
Younger wild yellowtail making their migration north in the spring are termed “hiramasa,” and these have a lighter cleaner taste with leaner, springier flesh. For wild fish, the younger yellowtail have a pink hue to the flesh, while the mature “buri” have a greater quantity of white fat marbling. Farm-raised yellowtail have plenty of fat, but less of an oily taste and they lack the springiness of the young wild yellowtail.
Japan‘s annual wild yellowtail catch averages 70,000 to 80,000 metric tons (MT), while annual production of farmed yellowtail exceeds 130,000 MT. Less than 3,000 MT is imported, while the species ranks as Japan’s top exported finfish by value (scallop exports are larger). It is mostly exported in the form of frozen loins for sushi use. Confusingly, the vacuum-wrapped packages of farmed yellowtail are usually labelled as “buri” while the product is sold at retail as “hamachi.” There are actually a variety of names depending on regional dialect and age, but in general “hamachi” implies as younger fish, while “buri” implies either a mature fish, or the species in general.
Japan’s yellowtail is of the species Seriola quinqueradiata, rather than Seriola lalandi or Seriola dumerili, which are the species typically farmed in Hawaii and Mexico and sold in the U.S. market as yellowtail.
Farmed yellowtail is mostly raised in net pens in the Seto Inland Sea, where Ehime, on Shikoku Island, is a major production area, and in Kagoshima at the southern end of Kyushu. Exported yellowtail is almost exclusively farmed. Volumes have been showing a rising trend, riding the worldwide sushi boom: approximately 4,000 MT in 2012; 5,200 MT in 2013; 5,100 MT in 2014; and 6,500 MT in 2016. Yellowtail exporters employ very advanced food safety measures, employing Hazard and Critical Control Point (HACCP) systems and other quality control certifications.
Individual brands are also developing special feeds to control color and taste, as a way of differentiating themselves in a commodity market.
Rumi Japan (Morimatsu Suisan Reito Co., Ltd.), based in Imabari City, Ehime Prefecture, has collaborated with a feed manufacturer to develop a feed incorporating green tea catechin. The company claims that it prevents the blood-saturated portion—a strip of dark meat running along the fish’s body between the lighter back and belly portions—from oxidation and color deterioration, and that it also reduces fishy smell. The company labels yellowtail fed with this extruder pellet as "Rumi Original Hamachi."
Azuma-Cho Fishery Cooperative, based in Izumi-gun, Kagoshima Prefecture, is the largest producer in Japan. Its Yuzu Buri-Oh utilizes the “yuzu,” or citron (a citrus fruit), to achieve the same effect. In Oita Prefecture, the “kabosu” and “hebesu” citrus fruits are used; while in Nagasaki, the “natsuka” is used. Each area promotes the type of citrus fruit raised locally, utilizing the rind, which is a byproduct of juice production. The rind has an antioxidant effect, due to vitamin C and polyphenol.
Fillets from the citrus-fed yellowtail are said to hold their color under refrigeration for 72 hours, as opposed to 36 hours for those raised on conventional feeds.
