Acetic acid bacteria (Sakusankin)

Acetic acid bacteria (sakusankin) is a general term for bacteria that mainly oxidize ethyl alcohol to produce acetic acid. They are not normally involved in the sake brewing process, but they can multiply unintentionally when hygiene control during production is inadequate. When they increase, they can bring sourness and changes in flavor to the sake, which may harm its quality. For this reason, controlling acetic acid bacteria is important during brewing. While they are used in the production of vinegar and in some other fermented foods, they are considered undesirable in sake.