Term for a wine defect derived from the unpleasant to disgusting odour of ammonia and the smell of mouse urine. It also manifests itself in a dull, oxidative, musty and vinegar-like odour. Depending on the intensity, however, the off-flavour is often only noticeable in the finish (aftertaste), where it manifests itself in a long-lasting, scratchy taste sensation that lingers on the palate for an unusually long time. The odour perception threshold is in the millionth of a gram range at 0.1 to 1.6 µg/l.

The causes are lactic acid bacteria (Lactobacillus brevis and Lactobacillus cellobiosus) and the yeast species Brettanomyces bruxellensis. As a result, acetic acid ethyl esters (ethyl acetate) and acetamide, among other things, are formed through metabolism (chemical metabolic reactions), which cause the typical mousy impression.
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Sigi Hiss
freier Autor und Weinberater (Fine, Vinum u.a.), Bad Krozingen