Abstract: Apparatus for adding carbon dioxide to consumable liquids contained in a container having an aperture of a selected size and shape is disclosed. The apparatus (10) comprises a housing (16) having a cartridge cavity (46), and a connecting means (20), (76) and (98) for securing the mouth (26) of a liquid container (12) thereto. Attached to the housing (16) is a gas conduit (28) having a first end (30) and a further end (32) which extends to the bottom of the liquid container (12). A gas cartridge (34) containing pressurized CO.sub.2 is received in cartridge cavity (46) in a gas-tight manner. The apparatus includes activating means such as a piercing member (48) for rupturing a frangible seal (54) of the cartridge (34). When the frangible seal (54) of the disposable one shot cartridge (34) is ruptured, the pressurized CO.sub.