Abstract: An apparatus for storing and dispensing a quantity of aerated liquid for maintaining the carbonation of a beverage in a container. The apparatus includes a vessel containing a source of gas, a valve closing the vessel and a pressure regulator that couples the valve to the vessel. The pressure regulator is capable of delivering the gas to the container at a substantially constant pressure substantially lower than the pressure under which the gas is kept in the vessel. A tap permits delivery of the gas to, and dispensing of the liquid from, the container.