Narezushi

Narezushi is a traditional form of fermented sushi. Skinned and gutted fish are stuffed with salt, placed in a wooden barrel, doused with salt again, then weighed down with a heavy tsukemonoishi. As days pass, water seeps out and is removed. After six months, this sushi can be eaten, remaining edible for another six months or more. The most famous variety of narezushi are the ones offered as a specialty dish of Shiga Prefecture, particularly the funa-zushi made from fish of the crucian carp genus, the authentic version of which calls for the use of nigorobuna, a particular locally differentiated variety of wild goldfish endemic to Lake Biwa.