Step 1

Rinse the soybeans in plenty of water.

Step 2

Transfer the beans to the jar, then cover with lots of water.

Step 3

Soak the soybeans overnight (8 to 12 hours). Rinse and strain.

Step 4

Place the beans in a large pot and cover them with water. Bring to a boil and cook the beans until they crumble easily between your fingers (3 to 4 hours).

Step 5

Reserve about 1L of the cooking water. Strain the beans and allow them to cool.

Step 6

In a food processor, puree the soybeans.

Step 7

In the large bowl, combine the ground soybeans, koji, salt, and miso.

Step 8

Mix well by hand.

Step 9

If necessary, add cooking water to obtain a dough-like texture. The miso paste should remain firm when pressed in the palm of the hand. Normally, there should be no water oozing out of the dough when it is pressed.

Step 10

Pour boiling water into the jar to sterilize it. Let it stand for 10 minutes, then empty it.

Step 11

Sprinkle 1 tbsp. of salt on the sides of the jar.

Step 12

Transfer the miso paste to the jar a handful at a time.

Step 13

Compress the paste well as you go along to avoid air bubbles. Use a pestle if needed.

Step 14

Cover the miso paste with a disk of parchment paper or plastic wrap.

Step 15

Sprinkle salt where the edge of the jar meets the parchment paper.

Step 16

Fill the freezer bag with salt. Place it in the jar, pressing well so that the bag covers all the miso.

Step 17

Close the lid of the jar.

Step 18

Write on the jar the contents and the date of preparation.

Step 19

Place the jar in a corner that is neither too hot nor too cool and away from direct light.

Step 20

Let it ferment for at least 6 months. The longer the fermentation, the more complex and stronger the flavours. The miso will become darker and darker over time.

Step 21

After a few months, a dark liquid will accumulate on the surface of the miso. This liquid is tamari. You can collect it and use it to replace soy sauce.

Step 22

To collect your miso, remove the weight and the parchment paper. Remove any grey oxidized parts. As you scoop, you will reach a beige or brown layer.

Step 23

Transfer to smaller jars and store in the fridge.