Chemical and physical deterioration of wine

Unlike almost all other food products, there is a great deal of subjectivity involved when it comes to assessing a given wine's level of deterioration. There are many chemical components in wine that change during storage, and the drivers are time, temperature and oxygen. In nearly all commercial wine, sulfur dioxide is added to wine as a preservative, just as it is used in other preserved fruits. The sulfur dioxide is the oxidation sink and it either consumes oxygen in various forms, reverses or scavenges many of the oxidation products, or reacts with them to render them undetectable. However, once the sulfur dioxide has been depleted, then oxidation products begin to accumulate and at some point the wine degrades to the point of unacceptability, although some age worthy wines do very well after sulfur dioxide depletion.