Name for the one to two centimetre thick, grey-green to black mould with the botanical name Zasmidium cellare or obsolete Cladosporium cellare. Other names based on the fur or cloth-like appearance or texture are Kellerkatze (vernacularly "Köllakotz" in Austria) or Schwarze Katze (black cat) and Kellertuch (picture on the right). The mould forms especially in wine cellars with a stock of old wooden barrels and very high humidity above 80% on walls, bottles and barrels. However, it is not tolerated on the latter because it attacks or negatively affects the wood, which can have a negative impact on the taste of the wine. Cellar mould feeds on the volatile substances of wine such as alcohol, acetic acid and esters. The nitrogen and sulphur requirements are formed from vapours of carbon disulphide, hydrogen sul phide and sulphurous acid. Unlike other types of mould, no unpleasant odours are formed. By regulating the air humidity, it is very desirable and its presence indicates optimal conditions. A completely different meaning is given to the "real" cellar cat, which used to like to stay in cellar vaults because of the mice. See also under wine-growing customs.