The traditional form of sushi is fermented fish and rice, preserved with salt in a process that has been traced to Southeast Asia, where it remains popular today. The term sushi comes from an archaic grammatical form no longer used in other contexts; literally, "sushi" means "it's sour", a reflection of its historic fermented roots.
The science behind the fermentation of fish packed in rice is that the vinegar produced from fermenting rice breaks the fish down into amino acids. This results in one of the five basic tastes, called umami in Japanese. The oldest form of sushi in Japan, narezushi, still very closely resembles this process. In Japan, narezushi evolved into oshizushi and ultimately Edomae nigirizushi, which is what the world today knows as "sushi."
Sushi is a Japanese dish consisting of cooked vinegared rice which is commonly topped with other ingredients, such as fish or other seafood, or put into rolls. Sliced raw fish by itself is called sashimi, as distinct from sushi. Sushi that is served rolled inside or around dried and pressed sheets of seaweed (or nori) is makizushi. Toppings stuffed into a small pouch of fried tofu is inarizushi. A bowl of sushi rice with toppings scattered over it is called chirashi-zushi.
Sept 28, 2010