In most countries, rotten fish is thrown out. In Japan, they spend 3 or 4 years making it, and consider it an expensive luxury. Funazushi, the speciality of Shiga prefecture, is fermented buna (crucian carp).
The raw fish is packed tightly in salt for a year, then dried and mixed with rice. This mixture is left to “ferment” for 3 years. The rice is changed every year, but the fish is allowed to decompose.
As you’d expect, funazushi has an overpowering smell, which discourages many people from trying it. The taste is sharp and vinegary. It can be used in soups, deep-fried in batter to make tempura, or served in green tea (ochazuke).
History of funazushi
Around 1000 years old, a preservation method called narezushi came to Japan from China. In Shiga, narezushi became funazushi. Fermentation was used as a way to preserve food stocks for the winter. Like many other Japanese foods (umeboshi, natto), funazushi became a national delicacy, even when fresh food became available all year round.
Funazushi is increasingly rare. As fresh fish has become available, modern sushi has been developed, reducing funazushi to novelty status. Younger Japanese people, who have more Western tastes, are less likely to develop a taste for the dubious treat. Recently, it can only be found in Shiga, and the smelly preservation technique may soon be redundant.