An apparatus for forming plastic preforms into plastic containers with at least one forming station which forms the plastic preforms into the plastic containers by the action of a flowable medium, wherein the forming station has a blow mould which forms a cavity, within which the plastic preforms are formed into the plastic containers. The blow mould has a base part which has an inner contour which forms a base of the containers, wherein the base part has at least one channel for conducting a temperature control medium for temperature control of the base part. A course of the channel is adapted to a course of the inner contour and/or the channel has, on its inner surface facing the temperature control medium, structures and/or cross-sectional changes which influence the flow of the temperature control medium through the channel.