Abstract: An improved stopper apparatus for bottles, such as wine bottles, which prevents contamination of the contents therein. The improved stopper apparatus comprises a stopper plug, a bladder attached thereto, a venting valve for venting gas within the bottle, a pump for inflating the bladder and a reservoir valve and inert gas reservoir. The bladder is inserted into the bottle and the stopper plug secured within the neck thereof. The bladder is filled within the bottle forcing the gas therein to escape through the venting valve. The stopper apparatus is adapted to enable a small quantity of heavy inert gas to be deposited into the bottle from the inner gas reservoir prior to filling the bladder, whereby to form a protective layer of inert gas over the surface of the bottle's contents.