Diatomaceous earth (keisodo)

Diatomaceous earth (keisodo) is a grayish-white sediment formed over a long period by the accumulated remains of microscopic algae known as diatoms. In sake brewing, high-purity diatomaceous earth with few impurities is refined and used as a filter aid in the filtration of sake. Thanks to its porous structure, it efficiently removes impurities and sediment from the liquid, and so plays an important role in producing clear, visually appealing sake.