Abstract: An improved bottle cap is provided for repeatedly obtaining airtight sealing engagement with a bottle having an annular external lip. The cap of the present invention is particularly well suited for sealing bottles containing sparkling wine or champagne, since such bottles conventionally include an external lip and since the cap of the present invention is able to seal gases within the bottle. The cap includes a housing having a central aperture for positioning over the neck of the bottle and having a radially inward directed flange for fitting beneath the external lip on the bottle. An activating carrier is movable within the aperture in the housing, and a ring-shaped pad holder and elastomeric pad are mounted on and are axially movable with respect to the carrier. A biasing spring is provided for acting on the holder and the pad to bias the pad toward sealing engagement with the bottle.