Abstract: An improved closure for fragile containers substantially filled with a gassy liquid, said closure comprising a combination of a cap for the container and a volumetric member partially within said cap and partially extending into the interior of the container. The volumetric member displaces and contains free gas generated by the gassy liquid thereby substantially reducing or completely eliminating the explosive potential of the container. The volumetric member is characterized by means that facilitate drainage of the gassy liquid should the liquid enter the member such as by expansion caused by elevated temperatures or inversion or shaking of the container.