The practice of horizontally positioning wine bottles during storage is a common procedure observed in cellars and wine shops. This orientation serves a practical purpose related to maintaining the integrity of the cork, which acts as the primary seal for the bottle.
Maintaining cork moisture is crucial. When a bottle rests on its side, the wine remains in contact with the cork. This contact prevents the cork from drying out and shrinking. A dry, shrunken cork allows air to enter the bottle, leading to oxidation and spoilage of the wine. Furthermore, the practice has historical roots, predating the widespread use of synthetic closures, when natural cork was virtually the only option.