Molecular sieving carbon
モレキュラーシービング・カーボンもれきゅらーしーびんぐ・かーぼんMolecular sieving carbon (MC carbon, or MC-tan in Japanese) is a type of activated carbon that selectively allows molecules of a specific size to pass through. It is used mainly during sake brewing and storage to remove unpleasant aromas such as bin-ka (the off-aroma associated with bottled sake) and hine-ka (the aged, stale aroma). Because molecular sieving carbon has very fine pores, it sorts substances by molecular size and adsorbs only the unwanted aroma compounds. This property makes it useful for adjusting aroma while preserving the quality of the sake.