Yes and no. The type of sauce you talk about is called "Tamari Shoyu". They are good and can be made wheat-less for those who have alllergy to it. Excellent sauce to go with raw fish (sashimi). But yield is pretty small because you do not want to make miso too wet. Regular soy sauce uses different cultures and with more liquids so you can enjoy more yields but it is also easier to fail by growing wrong molds. You can DM me to get down on details if you like. I am aware this is a board for fishing after all and not everyone here would care of these things perhaps....