Naka-shigoto / Shimai-shigoto
Japanese: 仲仕事・仕舞仕事（なかしごと・しまいしごと）
Middle and late-stage care in koji making. Controls temperature rise and optimizes enzyme production.
Naka-shigoto is the care after portioning; shimai-shigoto follows further. Both involve breaking apart koji to lower and equalize temperature.
Naka-shigoto occurs about 6-8 hours after portioning, shimai-shigoto several hours later. As mycelium growth accelerates, heat generation intensifies, requiring frequent temperature checks. Throughout koji making, you work by listening to the mold's 'voice.' After shimai-shigoto, no major care occurs until removal. Thoroughness up to this point ultimately determines quality. Recording temperature at each stage creates valuable data for future batches.