Wash the beans, removing any remaining pieces of shell
When the water runs clear, cover and leave the beans to soak in cold water for at least 6 hours
The beans will almost double in volume. Place beans in a saucepan with fresh water and simmer gently until cooked. This will take about 45 minutes for fava beans or 2 hours for soybeans. Alternatively: A darker colour miso can be achieved if the beans are steamed, instead of boiled.
Drain the beans in a colander, saving the bean cooking water for use later.
Mash the beans. If you like a smooth miso you can pulse them in a food processor. I prefer a chunky miso (which I can blend to a smooth paste, if a specific recipe requires it, once the miso is ready) Some people also like to put the mixture through a meat grinder, to produce a well mixed paste. All methods will produce a delicious miso!
Add the salt and mix in.
Once the beans have cooled to less than 40'C (if you haven't got a thermometer wait until the beans feel the same temperature as your skin - or cooler) stir in the koji.
Now try to form the mixture into a ball. At this stage it will probably be too dry and fall apart.
Slowly add the cooled bean water that you saved earlier. Mix well and stop as soon as the mixture can be formed into a ball.Note: If you've forgotten to save the bean water you can used cooled boiled water.
Get a clean 2 litre jar/crock. Moisten a clean paper towel with bean water and rub a small amount of salt all over the inside - this will help to prevent mold from growing at the edges.
Press the bean mixture into the jar, one layer at a time. Try to remove as many air bubbles as you can.
Once all the mixture is in the jar, wipe the edges with a clean paper towel. Lightly sprinkle the surface with salt and then cover with cling film. Find a plate or jar that fits inside your crock and then place weights on top of it. These will continually press down on the miso, removing air pockets as they form.
Leave the miso in a cool, dry place for a year. Then enjoy!The miso can be matured for longer than a year, it will become darker and deeper in flavour the longer it is left.Note: The miso in the picture has been blended to a smooth paste.
Traditionally soybeans are used to make miso, but as I'm allergic to soy I've use fava beans.