Kenshaku-ko (tank measuring port)

Kenshaku-ko (検尺口, also written with the reading kenjaku-ko in the source text) is a small opening in the top of a sealed tank, used to measure the amount of liquid inside. Through this opening, brewers can check the condition and remaining volume of the sake in the tank. In the sake-making process, the craftspeople at a sake brewery use the kenshaku-ko to follow the progress of fermentation and aging and to carry out quality control. The kenshaku-ko is an important feature because it allows the necessary data to be obtained easily while the tank remains sealed.