【Reading】はっこう

【English Name】Fermentation

Fermentation (hakko) refers to the phenomenon in which organic matter undergoes chemical change through the action of microorganisms and enzymes. In English, the verb form "ferment" is used, which has its origin in the Latin fervĕre (to boil, to bubble).

In the world of sushi, fermentation is one of the inseparable, fundamental elements. Narezushi, regarded as the origin of sushi, is a food that acquired preservability through the fermenting action caused by lactic acid bacteria, by pickling fish and cooked rice together. It took root in various regions as a life-wisdom for preserving fish for a long time in an age when refrigeration technology did not exist, and traditional forms are still handed down today in funazushi of Shiga Prefecture and sanma-zushi of Wakayama.

Rice vinegar, indispensable to sushi, is also a product born through the fermentation process of acetic acid bacteria. The same goes for soy sauce and miso, which can be classified as fermented foods completed through the cooperation of a wide variety of microorganisms such as koji mold and lactic acid bacteria.

Organized from a biochemical perspective, fermentation is positioned as a metabolic pathway that extracts energy from carbohydrates without requiring oxygen. In lactic acid fermentation, glucose is converted into lactic acid, giving food its sourness and preservative power. In alcoholic fermentation, ethanol and carbon dioxide are produced, widely utilized in the brewing process of alcoholic beverages.

That humankind has applied this mechanism to food processing since the Neolithic period is something various studies show, and the long history of fermentation is also deeply engraved in the foundation of sushi culture.