Abstract: An improved home canning closure system is provided for a home canning jar featuring a plastic ring and a metal lid combination which is adapted to allow excess pressure to escape while preventing the escape of the contents from the container. The plastic ring includes an annular top panel portion and a skirt portion depending downwardly from the outer periphery of the top panel portion. The skirt portion incorporates threads on its inner surface to engage threads on the external neck of the home canning jar. The plastic ring features a downwardly and inwardly directed annular sealing flange depending from its lower surface which forms a spring member to maintain a constant force to bias the metal lid into sealing engagement with the upper rim on the home canning jar.