Name for a wine defect that occurs primarily in red wines. Other names are Apeshit (South Africa), earthy note (see Geosmin), Brett, Hansaplast, Hundeschweiß, Lederton, Medizinalton, nasser Hund (wet dog), nasses Fell, nasses Leder, Pferdestall, Pferdeton, Phenolton, Sattelton, Schweißsocken, Stallgeruch and Teerton. For this reason, the defect was often not clearly recognised in the past or not classified as a defect at all. It occurs in internationally renowned red wines, in Belgian beers and in ciders as an accepted typical flavour.

Causes

The same microorganisms have been identified as the cause of all off-flavours. Horse sweat often occurs together with the wine defect mousiness. The off-flavour is more common in red wines that have undergone barrique ageing, especially in new barrels and/or carbonic maceration (carbonic acid mixture). The main causes are a lack of hygiene such as unclean wooden barrels and/or insufficient use of sulphur.

Brettanomyces

The yeast genus that causes this is called Brettanomyces (from which "Brett" is derived) or Dekkera. The species Brettanomyces bruxellensis is a slow-fermenting, highly alcohol-tolerant and non-spore-forming species. In addition to the usual sugars, it can also process the normally non-fermentable cellobiose and xylose contained in the wood structure of new barrique barrels. It can also multiply without any sugar residues, as ethanol and volatile acids are sufficient...