Koji

Aspergillus oryzae or “koji” is a noble mould that is ubiquitous in Japanese cuisine. Its superpower is to nibble away at complex sugars (such as starch) to convert them into simple sugars (such as glucose). This “saccharification” process is used to make sake, rice vinegar, soy sauce, miso paste and many other Japanese specialities.

There are three main families of koji: yellow, white and black. Yellow is used to make sake, white to make shochu and black to make awamori. Mixed with rice, salt and water, koji also becomes a natural flavour enhancer: shio koji.

Like so many other pillars of Japanese cuisine, koji in its culinary form originated in China. But the Japanese seem to revere this little fungus more than anyone else. The Japanese government even declared it the “national mushroom” in 2006… And local scientists have kept its genome secret for decades. A source of national pride.