Originally Posted by tsutton

Wow...lot's of misinformation so far...
Wine faults are numerous, from improper storage, heat damage, improper sealing mechanism (corks, real and synthetic, screw caps...). As a wine collector, the most common defect I encounter is cork "taint" known as TCA.
2,4,6-trichloroanisole (TCA) imparts a moldy, wet cardboard sort of taste/smell. There are varying degrees of taint that affect people differently. I've been to tastings with people who know a lot about wine and find that for the same bottle, some find it undrinkable while others find it, at worst, mildly less than ideal.
When served wine in a rest. it typically takes me more than just the initial taste to be absolutely certain that the wine is okay.