Miso is one of the cornerstones of Japanese cuisine, a protein rich paste of fermented soy beans used in making pickles, sauces, spreads and in its most well known guise as soup. Here in the middle of the UK it is pretty difficult to get hold of good miso, and when you find it you can end up paying luxury prices for a basic ingredient, so, having some home-brewing experience we decided to try making our own. A fungus called koji is grown on grains such as rice or barley before being introduced to cooked beans and salt. The salt kills off any bacteria present to make an environment conducive to fermenting, but since the koji enzymes can still function in a salty environment, they continue to do their job breaking down the carbohydrates and proteins creating the paste we know and love.
The process of making your own miso isn’t a short one, taking around two months to get a usable product, but we feel that following the journey from beans to miso is helpful in understanding Japanese food. Rice grains inoculated with koji can be bought online from a number of suppliers, otherwise all the ingredients are extremely easy to get and the hardest part of the procedure is the waiting and resisting using your paste before it’s ready. Incidentally, you also end up with a small amount of home-brewed tamari every now and then as it leaches out of the miso. We wouldn’t have been able to work out how to make miso without the help of the brilliant, but out of print, Book of Miso by William Shurtleff & Akiko Aoyagi; we highly recommend hunting down a copy if you want to experiment some more with fermenting your own miso.
