Today in 1999, US Patent 5980959 A was issued, an invention of Bernard Derek Frutin, for his “Methods and Apparatus for Enhancing Beverages.” Here’s the Abstract:

Enhancing the foam head on a bottled beverage where a pressurized container is housed within the neck of the bottle and above the level of the liquid and so arranged that upon opening of the bottle the pressurized container also opens to release the liquid stream therefrom initially to float on the top surface of the beverage in the bottle.