A blow mould for producing plastic containers comprises at least two blow mould parts and a hollow space formed from the at least two blow mould parts at which plastic parisons are transformed by an application of a flowable medium to the plastic containers. The hollow space includes an interior wall that has a contour which produces a predetermined configuration of the plastic containers. A first portion of at least two blow mould parts produces a bottom of the plastic containers. A second portion of the at least two blow mould parts has an opening region for discharging a gaseous medium during an expansion process of the plastic containers. The opening region extends along a first line and a second line, wherein the first and second lines run at least in some sections of the blow mould at an angle different from 0° relative to one another.