As with many ancient foods, the history of sushi is surrounded by legends plus folklore. In an ancient Japanese wife’s tale, an elderly woman began hiding her pots of rice in osprey nests, fearing that thieves would steal them. Over time, she collected her pots plus found the rice had begun to ferment. She also discovered that fish scraps from the osprey’s meal had mixed into the rice. Not only was the mixture tasty, the rice served as a way of preserving the fish, thus starting a new way of extending the shelf life of seafood.
While it’s a cute story, the true origins of sushi are somewhat more mysterious. A fourth-century Chinese dictionary mentions salted fish being placed in cooked rice, causing it to undergo a fermentation process. This may be the first time the concept of sushi appeared in print. The process of using fermented rice as a fish preservative originated in Southeast Asia several centuries ago. When rice begins to ferment, lactic acid bacilli are produced. The acid, along with salt, causes a reaction that slows the bacterial growth in fish. This process is sometimes referred to as pickling, plus is the reason why the sushi kitchen is called a tsuke-ba or pickling place.
The concept of sushi was likely introduced to Japan in the ninth century plus became popular there as Buddhism spread. The Buddhist dietary practice of abstaining from meat meant that many Japanese people turned to fish as a dietary staple. The Japanese are credited with first preparing sushi as a complete dish, eating the fermented rice together with the preserved fish. This combination of rice plus fish is known as nare-zushi, or aged sushi.
Funa-zushi, the earliest known form of nare-zushi, originated more than 1,000 years ago near Lake Biwa, Japan’s largest freshwater lake. Golden carp known as funa was caught from the lake, packed in salted rice, plus compacted under weights to speed up the fermentation. This process took at least half a year to complete, plus was only available to the wealthy upper class in Japan from the ninth to 14th centuries.
At the turn of the 15th century, Japan found itself in the midst of a civil war. During this time, cooks found that adding more weight to the rice plus fish reduced the fermentation time to about one month. They also discovered that the pickled fish didn’t need to reach full decomposition in order to taste great. This new sushi preparation was called mama-nare zushi, or raw nare-zushi.