EVERY YEAR FOR DECADES, SCIENTISTS at the Hiroshima Prefectural Agriculture Gene Bank have planted a small patch of hattanso rice. Its stalks are spring-green and spindly, its grains stubby, with a white core of endosperm visible in light. Hiroshima’s rice fields are fecund with Hattanso’s descendants, which farmers sell to sake brewers in dozens of prefectures across Japan. Hattan no. 35, which crop scientists bred in 1962, has hard grains that can withstand the polishing required for high-quality sakes. Hattan-nishiki no. 1 and 2, bred in 1984 from a cross between Hattanso and Nishiki rices, has medium-sized grains yield light sakes with an earthy tang.
Outside of the Agricultural Research Station, however, one variety of rice is conspicuously missing: hattanso itself. The cultivar hasn’t been used in sake production for decades.