Genus of acetic acid bacteria with various species that can convert alcohol (ethanol) to acetic acid under the influence of air. Acetobacter are among the very few bacteria that can still exist in wine even at very high acidity levels. However, they are only viable in the presence of oxygen. That is why they are called obligate aerobic (forced aerobic). Ideal conditions for reproduction are warm temperatures between 30 and 40 °Celsius, high pH values (low acidity) and aerobic conditions (oxygen). If Acetobacter get into the wine via the grapes or from the air, acetic acid and acetic acid ethyl esters can be formed there, which in higher quantities means the wine defects acetic souring and/or Uhuton. To avoid acetic acid formation (acetic acid fermentation), the wine must be vinified reductively, i.e. under exclusion of oxygen. In this process, contact with oxygen is avoided by filling the barrels to a high level or sulphur dioxide is added to bind the oxygen in the wine and thus render it harmless. During fermentation, acetobacter can form unwanted acetone and cause the unpleasant solvent sound. Acetobacter are used industrially for the production of acetic acid and vinegar.
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