Soybeans were a crucial crop in East Asia long before written records began. There is evidence for soybean domestication between 7000 and 6600 BC in China, between 5000 and 3000 BC in Japan and 1000 BC in Korea. The first unambiguously domesticated, cultigen-sized soybean was discovered in Korea at the Mumun-period Daundong site. Prior to fermented products such as fermented black soybeans ("douchi"), "jiang" (Chinese miso), soy sauce, tempeh, nattō, and miso, soy was considered sacred for its beneficial effects in crop rotation, and it was eaten by itself, and as bean curd and soy milk.