Fine wine is very sensitive to temperature in two ways. As the wine's temperature increases, two chemical reactions speed up - one which can be referred to as "aging", the other which is "spoilage".
The "aging" reaction is the beneficial maturation of the wine which improves the aroma, flavor and structure over time. At higher temperatures maturation happens faster, thus achieving optimum quality before you are ready for it, and forcing the early consumption of the wine. Needless to say, if you miss this "window", the wine quality will suffer.
The "spoilage" reaction, however, works to destroy the wine by "cooking" it, resulting in foul odors and off-flavors. Clearly, the undesirable effects of higher temperatures obliterate any desirable ones, and should be avoided.
It is well understood that a wine storage temperature in the range of 55 degrees or so is desirable. At 55, the effects of the "spoilage" reactions are negligible, while the desirable "aging" reactions are permitted to progress at a controlled rate. This will result in a well aged wine within the period of time expected. Storing wine in a closet, basement or under the house or stairs, where the temperature can easily exceed room temperature, will accelerate the "spoilage" reaction dramatically (see chart below). For example, at 73 degrees the reaction is as much as 8 times faster than at 55 degrees. When elevated much above such room temperature, the detrimental effects are dramatically fast, increasing to as much as 56 times that experienced in a proper cellar environment. Proper storage certainly rewards the consumer for his or her care and patience.
(The information above was extracted from "The Alchemist's Wine Perspective" educational newsletter, written by Dr. Alexander J. Pandell, Ph.D., professor of Chemistry and noted expert in the field of vinology for over 20 years. See http://www.wineperspective.com for details. For more information on this subject, and others of interest to wine enthusiasts, see also http://www.brentwoodwine.com - an excellent site and source for fine wine.)
