Soi is a flavorful white fish from the rockfish family that is sometimes called the “sea bream of Hokkaido.” Although its flesh is light and delicate, it has a notably rich umami flavor, making it one of the versatile fish enjoyed in Hokkaido cuisine.
Soi can be caught from early spring through late autumn, but spring is generally considered its best season. Because freshness has a major impact on the quality of the fish, live or exceptionally fresh soi is recommended when enjoying it as sashimi.
Thinly sliced sashimi and yubiki, a preparation in which the surface of the fish is briefly exposed to boiling water, are particularly good ways to appreciate its delicate texture and concentrated flavor.
With more umami than many other white fish, soi is also excellent when salt-grilled. It can be simmered in a seasoned broth, added to hot pots, or used in miso soup, where its savory flavor enriches the broth.
Smaller fish can be deep-fried, while larger soi can be prepared in Western styles such as poêlé, bouillabaisse and acqua pazza. Its combination of delicate white flesh and strong umami makes it remarkably adaptable to Japanese, Western and Chinese cooking.
Kurosoi, or black soi, is named for its dark-colored body. The word “soi” is thought to come from iso-uo, meaning a fish that lives around rocky coastal areas. Over time, the expression is believed to have developed into “soi.”
Kurosoi is known by different local names in various parts of Japan. Names include Kurokara in Toyama, Kurozoi in Hokkaido and Chiba, Kuromebaru in Tanabe, Gomasoi in Sendai, Takenokomebaru in Shimonoseki, Nagarazoi in parts of Hokkaido, Moyo in Tokyo and Waga in Shizuoka.
In the Ainu language, this fish is also referred to as soi, reflecting its long connection with the food culture of northern Japan.
From fresh sashimi to salt-grilled fish, simmered dishes, hot pots and hearty miso soup, soi can be enjoyed in many different forms. Its rich umami and adaptable character make it a particularly interesting seafood to discover while traveling through Hokkaido.
Spring is generally considered the peak season, although soi is available from early spring through late autumn.