By Harold McGee
The first foods that the ancient Chinese fermented in brine were pieces of meat or fish. These were eventually replaced by whole soybeans around the 2nd century BCE. Soy paste became the major condiment around 200 CE and remained so through around 1600, when it was replaced by soy sauce. Soy sauce began as a residue resulting when soy paste was made with excess liquid, but it became more popular than the paste, and by 1000 was prepared for its own sake.
Fermented soy pastes and soy sauce were carried by Buddhist monks to Japan, where sometime around 700 CE a new Japanese name, miso—mi meaning flavor—was given to distinctive Japanese versions of the paste. These involved the use of a grain-based koji that provided sweetness, alcohol, finer aromatics, and delicacy. Until the 15th century, Japanese soy sauce was simply the excess fluid, or tamari, ladled from finished soybean miso. By the 17th century, the now-standard formula of roasted cracked wheat and soybeans had been established for making the sauce, and the resulting product given a new name, shoyu. Shoyu began to appear on western tables as an exotic and expensive item by the 17th century.