The most favorable conditions for storing wine consist of steady temperatures around 55° Fahrenheit, humidity of approximately 80% and darkness – the exact environment of a cave, or of a cool, damp basement.
Cool temperatures slow the aging process, increasing complexity and character of the wine over time. Furthermore, high temperatures speed the aging process, inhibiting a wine from developing complexity over time. However, it is preferable to store wine at a constant temperature which may a be a bit warmer or cooler than the ideal 55-65 degrees F. Temperature fluctuations cause wine to expand and contract, which causes the cork to push out and pull in and eventually may loosen and expose the wine to oxygen.
Humidity is also important when storing wine. Humidity levels over 80% may encourage mold, while extremely dry conditions may cause high levels of evaporation and exposure to oxygen, spoiling the wine.
Wine stored in darkness is more likely to retain its clarity. Light reacts to proteins in the wine to form a haze as well as other unpleasant effects, such as off aromas and flavors.
At home, basements are usually ideal for storing wine because of their cool, constant temperature and darkness. If no basement is available, consider storing wine in a little-used closet in an air-conditioned part of your home. If you are planning a serious wine collection and have no suitable storage location, wine storage systems are available from a number of manufacturers. These offer ideal insulation as well as adjustable temperature and humidity conditions.