Next, transfer the cooked chickpeas, koji (and the water), and salt to a food processor. Process for 1-2 minutes, or until it forms a paste. It should be almost smooth and all the chickpeas should be puréed. If you have a small food processor, work in batches.
Prepare two 1-quart (1L) glass jars: make sure your jars are perfectly clean. I recommend baking your empty jars at 300°F (150°C) for 20 minutes to kill possible bacterias and then let it cool completely.
Using gloves or really clean hands, shape balls of the mixture and pack them very tightly into each jar, working one layer at a time to make sure there is no air holes. Repeat until your jars are 3/4 full.
Flatten the top of the mixture and sprinkle with about 1/2 tablespoon of fine salt. Cover with plastic film to touch. Now, you want to place something very heavy inside the jar, on top of the miso. I didn't have anything heavy that fitted inside so I filled a plastic bag with coarse salt and placed it inside the jar, on top of the miso. It must be heavy enough to prevent the miso from creating air bubbles due to the fermentation.