You should wash soy beans, and soak soy beans about 14~24 hours. Use 4 times the amount of soy beans for the soaking water.
After soaking, soybeans look like this.
Boil the soybeans in plenty of water for about 4 hours.
When you can easily mash a soy bean between two fingers, it's done! Next you should mash soybeans very well.
The soybeans look like this after mashing.
After mashing, weigh the miso so you can calculate exactly how much salt to use (next step)
Add the weight of soybeans by the weight of koji (here it's 500 g). Multiply that number by 0.12, then divide by 0.88.
Salt = (weight of mashed soybeans + weight of koji) x 0.12 / 0.88
Set aside 10% of the salt for sprinkling on top later on. The remaining 90% will be mixed with the koji in the next step.
Mix the koji and salt well. Then mix in the mashed soybeans very well.
Make miso-dama - it means miso ball! Make miso balls by tightly squeezing the mix in the palms of your hand. They should be firm and not fall apart.
Put the balls in a big container lined with a clean plastic bag, and "punch" your miso down! You need to punch out the air, so make sure it's smashed into the container very well with now air pockets.
Make the top of the miso level.
Sprinkle with a little salt.
Wrap an "inner lid" with plastic wrap and put on top of the miso paste. I used a round plastic piece the same size as my container.
Put a heavy weight on top.
Wrap up and close the plastic liner bag so it's inside the container. Cover the container with a lid and say good night! See you next year! It takes one year to finish fermenting, but you should check your miso after summer. If your miso smells bad, you should remove any mold and mix up miso! Smash it back down again, put the weight on and finish fermenting.
