Champagne corks are built from several sections and are referred to as agglomerated corks. The mushroom shape that occurs in the transition is a result of the bottom section, which is in contact with the wine, being composed of two stacked discs of pristine cork, cemented to the upper portion which is a conglomerate of ground cork and glue. Prior to insertion, a sparkling wine cork is almost 50% larger than the opening of the bottle. Originally they start as a cylinder and are compressed prior to insertion into the bottle.
Over time their compressed shape becomes more permanent and the distinctive «mushroom» shape becomes more apparent. The aging of the Champagne post-disgorgement can to some degree be told by the cork, as the longer it has been in the bottle the less it returns to its original cylinder shape. Champagne is usually served in a Champagne flute, whose characteristics include a long stem with a tall, narrow bowl, thin sides and an etched bottom. The Victorian coupe – according to legend, designed using a mould of Marie Antoinette’s left breast as a birthday present to her husband, Louis XVI – tends to disperse the nose and over-oxygenate the wine. Champagne is always served cold; its ideal drinking temperature is 7 to 9 °C (45 to 48 °F). Often the bottle is chilled in a bucket of ice and water before opening, which also ensures the Champagne is less gassy and can be opened without spillage. Champagne buckets are made specifically for this purpose and often have a larger volume than standard wine-cooling buckets to accommodate the larger bottle, and more water and ice.