Sushi is a food preparation originating in Japan, consisting of cooked vinegared rice combined with other ingredients such as raw seafood, vegetables and sometimes tropical fruits. Ingredients and forms of sushi presentation vary widely, but the ingredient which all sushi have in common is rice (also referred to as shari or sumeshi).
The original type of sushi, known today as nare-zushi was first made in Southeast Asia, the term sushi comes from an antiquated grammatical form no longer used in other contexts, and literally means “sour-tasting”, a reflection of its historic origin as a fermented food. The oldest form of sushi in Japan, narezushi, is still made by wrapping fish in soured fermenting rice, which causes the fish proteins to break down into their constituent amino acids. The fermenting rice and fish have both a sour and an umami taste.