When you open a bottle of wine, you expect that first whiff of its rich bouquet to fill your senses anticipation of a memorable experience and before the wine even has a chance to pass your lips, you realize that the bottle has turned, soured, gone bad.
What causes your prize to transform...here are the basics...mostly due to chemistry and the magic of nature.
CORKED: A corked taste in wine is caused by the substance TCA (trichloroanisole), which can give the wine a musty odor similar to wet cardboard or a damp cellar as well as a prickling or unpleasant taste.
Sulfur: If the wine has been too much SO2 (sulfur dioxide), it will have a sharp smell like a newly lit match. This can be remedied by allowing the wine to breathe through decanting.
OXIDATION: A bad cork or poor storage conditions can create various degrees oxidation, meaning that the wine will lack freshness and will smell like paint or varnish remover in the lighter form or vinegar in the worst
REDUCTION: Wine with a high content of H2S (hydrogen sulphid), will smell of rotten eggs. The problem is caused by insufficient oxygen supply during the maturation period.
BRETTANOMYCES: Brettanomyces is a form of yeast that thrives only in low-acid environments, and which gives the wine a mousy smell. In small amounts in can give wine an extra aromatic complexity, but in large amounts can be unpalatable.
BAD SMELL and TASTE: If hygiene during production has been deficient, such as using unclean vats or poorly washed bottles, can give wine an impure smell and taste and may cause mould.