The present invention relates to a process for the internal treatment of a glass container (4), in which a pourable treatment agent (6) is apportioned in accordance with the size of the glass container (4) to be treated and a portion formed in this way is transported by means of a portion conveyor (1) through the mouth of the glass container into the interior space of the glass container, which is preferably still hot, and also relates to an internal treatment device and systems comprising such internal treatment devices for carrying out the process according to the invention.