The present invention is a method and apparatus for readmitting air into vacuum containers, such as canning jars, by incorporating a flexibly-mounted check valve in the container lid or body, and sandwiching an elastomeric seal member, such as an O Ring, between the check valve and the vacuum container's lid or wall. The check valve is flexibly mounted to the airtight container by a retainer member that permits the check valve to move vertically and horizontally and compresses the elastomeric seal member sufficiently to prevent leakage. Air is readmitted into the vacuum container by applying a force to the check valve that sufficiently decompresses a segment of the elastomeric seal member to cause leakage. The displacement force on the check valve may be applied by hand, without using any tools.