Hi John: the tried-and-true method for chilling Champagne quickly (in less than 20 minutes) is to place the bottle in a slushy “bath” of ice and cold water. Make sure the bottle is submerged up to its neck in the ice water bath. You can accelerate the process even faster by adding a handful of salt to the water. Salt depresses the freezing point of the mixture so that the temperature of the ice bath gets even colder. By the time you get out some wine glasses and turn on some music, the Champagne will be ready!
—Karen