Disclosed is a method for producing liquid containers by: producing a plastic container by a blow moulding process; filling the plastic container with a flowable medium, such as a liquid; and at least partially closing the container, which is filled with the liquid, with a container closure. After the at least partial closing of the container, a gaseous medium is fed to the interior of the container via at least one opening introduced into at least one portion of a wall of the plastic container or a circumferential wall of the container closure or via an intermediate space which exists between a mouth and the container closure.