Corks have been used for sealing wine bottles since the late 17th century. The benefits of corks are numerous. The most important is that it allows the wine to breathe. Closed with plastic or an aluminum plug, wine does not get the oxygen and develops differently than the wine with a cork. As the demand for cork increases and its production is limited, consequently there are a certain amount of "damaged" plugs.
The smell of a bad cork is moist, moldy and stale at the bottom. For such a wine is said to be "corked” or “corky”. This is the result of a rare compound 2,4,6-trichloroanisole (shortly TCA), which occurs in a cork stopper by microbial infection and gives the wine an unpleasant smell like damp cardboard or wet fur. It is estimated that four percent of cork is infected by this compound. Because of TCA, when serving a wine guests get the cork to smell it. The restaurant owner will usually, without question, replace the bottle contaminated with TCA. The stench can be so strong that it covers all the wine's aromas. Because of this disease of the cork, more and more winemakers around the world are replacing simpler wines with metal, screw plugs.