A pasteurizable plastic container having movable panels to alleviate internal pressure changes during pasteurization in order to avoid uncontrolled permanent deformation of the container body. As molded, each panel has a shallow recessed central wall which during the increased temperature and pressurization of pasteurization, moves outwardly to alleviate at least part of the internal pressure. During cooling, the panels move back inwardly to alleviate at least part of the negative pressure. The container may further include hoop ribs in the land areas above and below the panels, an axially elongatable hoop rib in an upper shoulder section, and an angled heel portion adjacent the standing ring. These additional elements further restrict uncontrolled bulging of the post walls, which would lead to improper label application and/or excessive volume change.