In a method for producing glass bottles having a flat base and an opposite filling opening, the base of the glass bottles is further formed at a plurality of processing positions. During the entire further forming of the base, with the aid of a purge gas which by way of the filling opening of the glass bottle flows in or out in a centric manner and flows out or in in an eccentric manner, a purge gas flow is generated in the interior of the glass bottle in order for delamination effects to be reduced. A tube or a nozzle serves for blowing in or suctioning out the purge gas. Various geometries and arrangements of the tube or of the nozzle are disclosed. A multiplicity of geometric constellations of the tube diameters and various mass flow settings are disclosed.
