Should the bottle seal leak, contamination will occur. To imagine what contamination can mean to wine, think of a freshly-cut apple left out and exposed to the air. It is the same with wine. Wine is also harmed by direct contact with light, thus, bottles should be kept in cool, dark places. Even the use of incandescent bulbs is encouraged.
Temperature is another determiner in wine preservation.
Because wine is always changing, exposing wines to fluctuating warm and even cool temperatures can create problems. Changes in temperature affect not only the wine but the cork seal. As corks cool, there is contraction and with warmth, expansion. With repetition, this allows wine to seep into the cavity between cork and bottle, inviting contamination. Fortunately for the consumer, most white, sparkling, and rose wines and even many reds are ready to drink as soon as purchased.