PURPOSE: To perform the decolorization and seasoning of "sake" without degrading its taste and flavor, by treating the "sake" with a specially treated activated charcoal.

CONSTITUTION: Activated charcoal is adsorbed with fragrant components (especially medium boiling components such as isoamyl acetate, ethyl caproate, etc.) ontained in the fermentation gas of unrefined "sake". The "sake" to be upgraded is treated with the activated charcoal thus obtained. The fragrant components in the "sake" are not adsorbed to the charcoal, and, in contrast with this, the fragrant components adsorbed in the charcoal are desorbed into the "sake", thus enabling the decolorization and seasoning of the "sake" while keeping or improving its original flavor and taste.