【Reading】はっこうしょくひん

【English Name】Fermented Foods

Tracing the origins of sushi reveals a relationship with fermentation that cannot be severed. A fermented food is a collective term for processed foods made by transforming ingredients using the action of microbes and enzymes. In Japan, various fermented foods such as soy sauce, miso, bonito flakes (katsuobushi), pickles, and natto have blended into the food culture since long ago.

Especially important in relation to sushi is "narezushi." Made by pickling salt-cured fish in rice or rice bran and improving its keeping quality through the action of lactic acid bacteria while creating a distinctive flavor, it is considered the origin of today's nigiri sushi. The funazushi (fermented crucian carp sushi) of Shiga Prefecture is widely known as a representative example. Furthermore, the soy sauce and brewed vinegar essential to sushi also benefit from fermentation, and bonito flakes, going through a fermentation process using the koji mold (Aspergillus glaucus), become an element that brings depth to a sushi restaurant's dashi stock.

The history of fermentation is very long. The oldest archaeologically confirmed record is wine from about 8,000 years ago in the Caucasus region, and brewing traces from about 7,000 years ago have also been excavated on the Iranian Plateau. In China, fermentation techniques were empirically accumulated starting from the salting of ingredients and were called "hishio" (jiang). It is presumed that hishio arrived in Japan at the end of the Jomon period. Fermentation has the function of breaking down proteins into amino acids to create umami, and it lives on even today as an indispensable technology that supports sushi culture from its very foundation.