There exist defects which derive from uncontrolled elements, such as cork smell. A similar disvantage finds in a percentage of bottles between 5% and 10% (moulds are formed in cork and the wine unavoidly absorbs bad smell produced by them).
A further defect is the so-called maderization, caused from too much ageing of white wines which assume cooked and mellow taste turning the wine brownish and flat. They look like the old Madera wine.The fioretta is one of the most usual wine diseases and it is considered innocuous, even if it in any case makes wine tasteless and flat.
The fioretta produces on the wine surface a whitish veil from which a continuous rain of very thin material falls on the bottom of container. This material is constituted by cells of fiorette and it can make copious sediments and muddy all wine.
An other typical wine desease is the acescenza (vinegar taste) that, in the worst cases, can make a membrane on wine, even if this should happen only in vinegar. The wine becomes already not nice to drink before than such superficial formation are visible.
Both fioretta and acescenza can be developed on all wines having less than 15° C and exposed to too much air; in order to avoid these defects it is necessary to conserve wines without air contact.