Aishocho town, Shiga prefecture, Japan, May 31 2017 - At Marunaka Shoyu, a 200 year old soy sauce production company, provider of 3 stars chefs all around the world. The process has been mostly unchanged since 200 years and no machinery is used to produce the soy sauce. The best products are processed 3 years before being sold.
The process of kaiire is carried out for nearly three years.
During this period, brewers constantly interract with the product to control the temperature and fermentation process. Through the use of a kaibou (traditional tool), brewers carefully blend the moromi (mixture of soybeans, wheat and salt), within the wooden vats. As the koji (fermentation culture) contained in the vats begin interacting with the moromi, brewers closely monitor the fermentation process to ensure consistency. Twice a day, each vat is attended to by a brewer, at which point they deftly utilize their kaibou to enliven the mixture, releasing built-up gases and reintroducing oxygen into the moromi. Throughout this stage, artisans create the ideal fermentation environment, allowing the microorganisms within the koji to thrive and flourish.As with all processes at Marunaka Shoyu, this step is entirely reliant on the technique and experience of the brewer, and no automation or modern equipment is utilized.
The older the moromi is, the darker it is.