When I was growing up in Korea, it was pretty common to see people making their own soy sauce including my mom, who used to have 3 barrels of soy sauce that lasted us about 10 years. I used to wonder why it took so long to make soy sauce but it lasts a lifetime once you make it.
Soy sauce can be created along with fermented soy bean paste, which is another by-product while making soy sauce.
Soy sauce has scientifically been proven to help prevent Cancer and other diseases(One of the Top 10 antioxidants on Eart