Namahineka (off-aroma in unpasteurized sake)

Namahineka (生老香) refers to a sharp, unpleasant aroma that develops mainly when namazake (unpasteurized sake) is left at room temperature. The aroma arises as the components of the sake deteriorate, usually through oxidation or microbial activity. Namazake is generally recommended to be stored refrigerated, and without proper temperature control, namahineka can become stronger. Because namahineka detracts from the flavor of sake, it is a phenomenon to be avoided if you want to enjoy the sake.