Goishicha (Go-Stone Tea)

Goishicha (碁石茶, "go-stone tea") is one of two recognised Japanese post-fermented dark teas (alongside Ehime's Ishizuchi- kurocha), produced in the mountainous city of Otoyo in Kochi Prefecture on Shikoku. The processing is unique in Japan: leaves are steamed for nearly 3 hours in wooden barrels, fermented twice (first with Aspergillus mold, then anaerobically with lactic acid bacteria), then cut into ~3 cm squares resembling the black stones of the board game "go" — hence the name — and sun-dried on straw mats. Total processing takes nearly two months. Production peaked in the late 19th to early 20th century, nearly collapsed during the Showa era, and was officially recognised as Intangible Cultural Property of Japan in 2018.