A Short History of Sushi
“Eat it raw first of all, then grill it, and boil it as the last resort.”
— Japanese proverb
In Japan, the consumption of raw fish has been traditional since ancient times. Namasu, or the eating of thinly sliced raw fish dipped in a sauce with a vinegar base, is a typical example. However, the better-known sashimi has been popular only since the seventeenth century its popularity increasing as the general consumption of soy sauce increased. Delicately sliced raw fish of the utmost freshness and quality is eaten after being dipped in soy sauce flavored with a small amount of grated wasabi, which is similar to horseradish.
Nigiri-sushi, prepared by putting a slice of raw fish onto a bite-size portion of hand-rolled, vinegar-flavored rice, has recently become internationally popular. But sushi originated as a means of preserving fish by fermenting it in boiled rice. This older type of sushi is still produced in the areas surrounding Lake Biwa in western Japan, and similar types are also known in Korea, southwestern China, and Southeast Asia. In fact, the technique first originated in a preservation process developed for freshwater fish caught in the Mekong River and is thought to have diffused to Japan along with the rice cultivation.
A unique fifteenth-century development shortened the fermentation period of sushi to one or two weeks and made both the fish and the rice edible. As a result, sushi became a popular snack food, combining fish with the traditional staple food, rice. Sushi without fermentation appeared during the Edo period (1600-1867), and sushi was finally united with sashimi at the end of the eighteenth century, when the hand-rolled type, nigiri-sushi, was devised. Various styles of hand-rolled sushi were developed, such as norimaki, in which vinegar-flavored rice and seasoned boiled vegetables are rolled in paper-thin layers. In addition, sushi restaurants became popular during this era. They offered ready-made rice prepared with vinegar and other seasonings and rolled with different toppings according to the tastes of the guests. In this manner, sushi has changed from its original character as a preserved food to that of a fast food.
(from the Cambridge World History of Food)