THE BREWERY’S UNIQUE ECOSYSTEM
The microorganisms that live inside the kioke barrels will create an ecosystem unique to that brewery. When samples from the barrels are brought to a research institution, new microorganisms are always found. With these varying microorganisms, every soy sauce batch will have a slightly different taste from each other. This is attributed to using the same barrels, in the same warehouse for over 100 years.
Many kioke barrels help with fermentation according to the temperature change during the spring, summer, autumn and winter months. In addition, the fermentation process varies between one to four years. In regards to flavor, soy sauce is known to have an umami, or savory, taste. According to research, glutamic acid present in traditionally fermented soy is responsible for increasing the umami flavor.