Which bacteria is known to be problematic in sake production?

The bacteria that is known to be problematic in sake production is Acetobacter. This microorganism is responsible for the oxidation of alcohol into acetic acid, which can spoil the sake and negatively affect its flavor profile. Ideally, sake production aims to maintain a controlled environment that minimizes the risk of acetification, as the presence of Acetobacter can lead to off-flavors and undesirable aromas.

While other options relate to aspects of sake production, their roles are different. Lactobacillus plays a beneficial role in certain types of sake fermentation, particularly in producing acidity that can enhance flavor. Aspergillus oryzae is the mold used in the koji-making process, crucial for saccharifying starches into sugars, necessary for fermentation. Hi-ochi kin is not a recognized problematic organism in sake production. Thus, Acetobacter is the primary concern due to its potential to compromise the quality of sake.