Activated carbon (kasseitanso)

Activated carbon (kasseitanso) is a material that plays an important role in sake brewing. It is used mainly to purify brewing water and water used for diluting sake (warimizu). Its purposes include decolorizing sake, adjusting flavor and aroma, preventing discoloration, and preventing hiochi (spoilage caused by hiochi bacteria). Also called kasseitan, this material can be classified by raw material into plant-based carbon, animal-based carbon, and petroleum-based carbon, but plant-derived carbon is mainly used in sake production. Activated carbon can also be divided by activation method into steam-activated carbon and zinc chloride-activated carbon, and both are used in sake production. In addition, activated carbon comes in two forms, powdered carbon and granular carbon, and the appropriate one is chosen according to the needs of the brewing process. Because this improves the quality and flavor of the finished sake, activated carbon is an indispensable element of sake making.