Seijoki (steam purifier)

A seijoki (整蒸器) is a device used in sake brewing to improve the quality of steam. Specifically, it regulates the pressure of the steam supplied from the boiler and removes impurities and iron from it. In this device, steam from the boiler is blown directly into water and re-evaporated, producing clean steam. The clear steam obtained in this way is used to steam the rice and contributes to brewing high-quality sake. By using a seijoki, the influence on flavor and aroma during production can be kept to a minimum, and the device plays an important role in the final character of the sake.