The original type of sushi, known today as nare-zushi (馴れ寿司, 熟寿司,) was first made in Southeast Asia, possibly along what is now known as the Mekong River. The term sushi comes from an archaic grammatical form no longer used in other contexts; literally, sushi means “sour-tasting”, a reflection of its historic fermented roots. The oldest form of sushi in Japan, narezushi, still very closely resembles this process, wherein fish is fermented via being wrapped in soured fermenting rice. The fish proteins break down via fermentation into its constituent amino acids. The fermenting rice and fish results in a sour taste and also one of the five basic tastes, called umami in Japanese. Contemporary Japanese sushi has little resemblance to the traditional lacto-fermented rice dish. Originally, when the fermented fish was taken out of the rice, only the fish was consumed while the fermented rice was discarded. The strong-tasting and smelling funazushi, a kind of narezushi made near Lake Biwa in Japan, resembles the traditional fermented dish. Beginning in the Muromachi period (AD 1336–1573) of Japan, vinegar was added to the mixture for better taste and preservation. The vinegar accentuated the rice’s sourness and was known to increase its shelf life, allowing the fermentation process to be shortened and eventually abandoned. In the following centuries, sushi in Osaka evolved into oshi-zushi. The seafood and rice were pressed using wooden (usually bamboo) molds. By the mid 18th century, this form of sushi had reached Edo (contemporary Tokyo).
The contemporary version, internationally known as “sushi”, was created by Hanaya Yohei (1799–1858) at the end of the Edo period in Edo. Sushi invented by Hanaya was an early form of fast food that was not fermented (therefore prepared quickly) and could be conveniently eaten with one’s hands. Originally, this sushi was known as Edomae zushi because it used freshly caught fish in the Edo-mae (Edo Bay or Tokyo Bay). Though the fish used in modern sushi no longer usually comes from Tokyo Bay, it is still formally known as Edomae nigirizushi.
The Oxford English Dictionary notes the earliest written mention of sushi in English in an 1893 book, A Japanese Interior, where it mentions sushi as ‘a roll of cold rice with fish, sea-weed, or some other flavoring’. However, there is also mention of sushi in a Japanese-English dictionary from 1873, and an 1879 article on Japanese cookery in the journal Notes and Queries.