Homemade soy sauce

For the past six months, I have been attempting to make soy sauce at home. In contrast to the extensive info on other fermented products such as cheese, beer, or bread, there is next to nothing available in English on the production of soy sauce. Although I am still working out the kinks, I have finally succeeded in producing a passable soy sauce.

The production of soy sauce involves allowing cooked soybeans (and often wheat) to mold, drying them, and then soaking in a brine. For my first attempts I relied on natural yeasts. From a practical standpoint this meant cooking the soybeans, mixing them with wheat flour, and letting them sit. The result was disgusting. I waited about two weeks for a 'delicate white mold' to cover them. Instead they developed a disgusting smell which really cannot be described (one of the worst things you can imagine). I tried this process again quite a few different ways (no wheat, whole beans, fermented cold, fermented warm . . . ) They all turned out bad.

At this point I went back to the drawing board, and reconstructed a recipe based on my brewing practices. The most successful attempt so far used a sanitized, sealed fermenting container, whole soybeans (no flour), and a fungus starter derived from Koji, a key ingredient in the production of Sake that harbors the right mold. After three days the beans had a nice white (and some green) mold. They smelled sweet and fermented but not 'funky'. I dried them in the oven on low heat, then brined them in a 20% salt solution for ~ 2 weeks. The result was definately soy sauce. It was quite salty and light colored. The light color and mild flavor probably the result of the short brine. Soy sauce is traditionally soaked 6 months to a year, and develops a dark color after exposure to light. I am currently working on refining the process, and plan to post a final recipe when I work out the kinks.