Kakoishio (囲塩)

Kakoishio is specially purified traditional salt for preservation, and also called furuzumijio (traditional Japanese purified salt for preservation).

Salt is kept in an underground facility with roof covering, to avoid water percolation, for over a summer to a year. This process drains out water and bittern and makes kakoishio, which do not lose in weight. This is a precious source of salt in a snowy area in the winter and mountain-ringed region.