Isushi(izushi)

Meshi sushi is a type of fermented sushi primarily found in the cold regions of northern Japan, such as Hokkaido and the Hokuriku region. It is a variant of nare zushi, created using rice, fish, vegetables, and kōji (rice malt). The fermentation process gives the sushi its characteristic flavor and also serves as a method of preservation.

The preparation of meshi sushi begins with salting the fish to remove excess moisture and make it last longer. The fish is then washed to remove excess salt. It is then layered in a container with cooked rice, vegetables such as radish, carrots, and cabbage, along with kōji. This mixture is weighed down and fermented for several weeks at low temperatures.

The low temperatures during fermentation are crucial to ensure a safe and consistent lactic acid fermentation process, which creates the typical flavor of meshi sushi while reducing the risk of contamination with harmful bacteria such as Clostridium botulinum. In the past, there have been several cases of botulism in Japan due to improperly fermented meshi sushi, highlighting the importance of proper preparation.

Meshi sushi is traditionally prepared in the winter and often served at New Year's celebrations and other special occasions. It is known for its mild, slightly sweet and sour taste, which is pleasant even for people who do not typically like fermented foods. The combination of fermented fish, sweet rice, and crunchy vegetables offers a unique culinary experience.