Aspergillus kawachii (White koji mold)
Aspergillus kawachii
Japanese: 白麹菌（Aspergillus kawachii / A. luchuensis mut. kawachii）
A koji mold widely used in shochu production. A mutant of black koji mold that produces large amounts of citric acid, stabilizing brewing in warm climates.
White koji mold is the leading player in shochu production. It was originally discovered as a mutant of black koji mold. In 1918, Genichiro Kawachi found a strain producing white spores during black koji cultivation.
Its defining characteristic is massive citric acid production. Citric acid lowers the mash pH, suppressing contaminating bacteria. It is thanks to white koji that stable brewing became possible even in warm regions like Kyushu.
Easier to handle than black koji mold, it is now the most frequently used koji mold in shochu production. It is indispensable for shochu production. This insight deepens fermentation understanding further.