“Naruto Kintoki” Sweet Potatoes
Sweet potatoes are believed to have been introduced into Japan in the early 1600s by Spanish or Portuguese explorers and first grown in the the old feudal domain of Satsuma (present day Kagoshima prefecture) on Kyushu Island; thus their common Japanese name of “Satsuma-Imo” (薩摩芋 or さつま芋), with imo meaning potato. Since then, they’ve become a fall and winter staple that is cultivated and consumed across the country and enjoyed for their sweet, rich taste and appreciated for their starchy energy, dietary fiber, vitamins A and C, and potassium and other nutrients.
Today, over 50% of Japan’s annual sweet potato harvest is still produced in and around the Setouchi region, mainly in the three prefectures of Kagoshima and Miyazaki on Kyushu Island and Tokushima on Shikoku Island. Of the 40 different varieties of sweet potatoes found in Japan, the most famous is Naruto Kintoki( 鳴門金時 or なるときんとき) grown in Tokushima prefecture. Developed in 1979 outside of Naruto City, which lies adjacent to the Naruto Straits that separate Shikoku Island from Awaji Island, Naruto Kintoki sweet potatoes have a vivid cherry-colored skin and golden-hued (kin means gold) flesh. The boldness of its colors, which are considered part of its appetizing allure, belies the delicacy of Naruto Kintoki’s flavor compared to other varieties of sweet potatoes. Long and slender, their texture is moist and flakey versus being moist and chewy or moist and sticky like the two other main types of sweet potatoes grown in Japan. Their taste is also more subtle, being elegantly sweet, rich, and a bit nutty, often described as being chestnut-like in flavor.
Naruto Kintoki are perfect for the two most popular ways of eating sweet potatoes in Japan: simply roasted and pulled apart in chunks or steamed whole, cut up, and served with a sprinkling of salt and sometimes drizzled with a few drops of citrus juice to accent and balance their sweetness and richness. They’re also excellent used in the myriad sweet potato dishes Japan’s cooks have created over the centuries: salads, soups, stir-fried, deep-fried, simmered, and rice and noodle dishes, and, of course, in sweet confections.
Harvested from July through October, Naruto Kintoki are at their best from October to February after they’ve matured for some months in storage, like all sweet potatoes.
Steamed Naruto Kintoki sweet potatoes served with a sprinkling of flakey sea salt and a spritz of the juice from sudachi, a small, delightfully fragrant citrus related to yuzu that is another autumn food specialty of Tokushima prefecture.