A muselet is a wire cage that fits over the cork of a bottle of champagne, sparkling wine or beer to prevent the cork from emerging under the pressure of the carbonated contents. It derives its name from the French museler, to muzzle. The muselet often has a metal cap incorporated in the design which may show the drink maker's emblem. They are normally covered by a metal foil envelope. Muselets are also known as wirehoods or Champagne wires.
When champagne was first produced the pressure of the sparkling wine was maintained by wooden plugs sealed with oil-cloth and wax. This method proved inconsistent either from leaking or blowing out of the stopper and a method of restraining the corks using cord was developed. In 1844 Adolphe Jaqueson invented the more secure method involving steel wire, however the early muselets were not easy to install and proved a little inconvenient to open. Further developments led to the modern muselet which is made of steel wire twisted to add strength and with a small loop of wire twisted into the lower ring which can be untwisted to release the pressure of the muselet and give access to the cork.
Muselets are now machine made in millions. A modern development has been the production of personalized caps within the muselet on which are displayed the emblems or name of the manufacturer and these may vary in colour and design from year to year and between different manufacturers. This has stimulated a market for the collection of these caps.