Shoyu is a Japanese word for soy sauce. In Japan, there are a number of different forms of shoyu, which are differentiated on the basis of ingredients and fermentation technique.
All soy sauce is made from fermented soybeans. Depending on how they are handled and how long they are fermented, the soy sauce may be light in color and texture or inky black. Different soy sauces are designed to pair with different foods; in Japan, some famous types are tamari shoyu, made by pressing the soybeans used to produce miso, and saishikomi, a double brewed shoyu which is extremely strong. Just like wine, the flavor of shoyu varies depending on the vintage, how it is handled, and how long it is allowed to age.
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