Why is shoyu (soy sauce) black?
Shoyu (soy sauce) is a ‘fermented’ product, which means that when the soybeans, wheat and salt are combined with water, a starter with mold called ‘koji’ is used to convert some of the sugars into alcohol, in a process somewhat similar to making beer. After a period of time, enzymatic and chemical reactions create a liquid called ‘shoyu’ that has darkened due to oxidation (essentially combining with oxygen).
