Koji Stages

Question 1

Stage 1

Answer 1

Hikikomi “Bringing In”

- Cool rice to approx 32º

Question 2

Stage 2

Answer 2

Tanekiri “Spreading Seed”

• 1-3 hours, 32 and 33 degrees
• Lay rice flat on large table
• Sprinkle koji kin on rice and mix well
• Pile rice together into mound
• Wrap rice in thick cloth and blankets to raise the temp and retain moisture

Question 3

Stage 3

Answer 3

Kirikaeshi “Re-breaking Up”

• 10-12 hrs later; 31 - 33 degrees
• Breaking down the rice pile to cool
• Ensures even distribution of koji and prevents hot spots
• Temp reduced to about 31 before bringing back up to 33

Question 4

Stage 4

Answer 4

Mori “Mounding”

• 20-23 hrs; 33 - 35 degrees
• Separate into smaller containers or lay out flat onto a second toko table
• 1 toko koji (bed koji); 2 hako koji (box koji); 3 futa koji (tray koji)
• The humidity and heat need to be controlled as the koji kin grows into the grain
• Depth of rice layer is critical to controlling temp/humidity

Question 5

Stage 5

Answer 5

Naka Shigoto “Middle Work”

• 30-33 hrs; 33 to 38 degrees
• Mix again and cool down to 33 degrees
• Purpose is mainly to encourage the release of heat but also to start drying the rice grains
• koji is spread out further (on table/boxes/lids) in order to control heat

Question 6

Stage 6

Answer 6

Shimai Shigoto “Final Work”

• 36-38 hours; 38 to 43 degrees
• Keep koji under 43 degrees by increasing surface area
• One more mixing and spreading out the koji to the edges of the container, making patterns on top layer to regulate heat and airflow
• Drying out grains

Question 7

Stage 7

Answer 7

Dekoji “Sending Out”

• 44-48 hrs
• Temp reduced from around 38 degrees to ambient brewery temp
• purpose is to stop koji growth by cooling it down
• final koji becomes white, frosted appearance, hard
• smells and tastes sweet, reminiscent of roasted chestnuts