Tonight I checked one of my books and discovered I have at least recipes to make my own soy sauce. I took a look at the recipe and it doesn't seem too hard.
Cook up some soybeans, mash them, add a bit of salt, add the koji (starter) and let it set for a while in a container with an airlock.
That does not sound too hard but I know that it can't be THAT easy or everyone would be making their own. Well, after a bit more research, it turns out that just finding the proper type of koji can be a challenge. Add to that, the fact that it can take up to a year for the materials to ferment to the proper stage and that explains it right there.
Discovering that the length the soybean/koji mixture ferments determines the type of soy sauce was the extremely interesting. If you want a light soy sauce, it takes a couple of months but if you want a deep, dark, heavy soy sauce, you need to let it go a full year.
I also found out that the koji starter can be used to make sake, certain types of pickles, miso, and a couple other things. I think that the term koji refers to the rice or barley that was inoculated with the appropriate strain. That is so cool.
The whole process interests me. Now will I try to make my own? I am seriously thinking of it but it won't happen right now because I live in a tiny one bedroom apt and I'm trying to figure out where to put the items for fermentation. I have enough trouble finding space for the kimchi I make. In fact I have two more cabbages I have to cut for kimchi this weekend. Kimchi in soup is fantastic.