In the 13th century, a Japanese priest returned from a trip to China and settled in the small, coastal town of Yuasa in Japan’s Wakayama Prefecture. He brought with him several new skills that he had learned from the Chinese, including a process for making miso (a soybean paste). The liquid byproduct of this miso-making process was eventually adopted by the people of Yuasa as a condiment of its own—giving birth to what we know today as soy sauce.
See how Japanese soy sauce has been made for 750 years in this fascinating short film by Mile Nagaoka.
PS: As a result of the natural fermentation process, typical Japanese soy sauce usually has a certain amount of alcohol in it.
Video credit: NatGeo
Images credit: Epicurious