The Familia Wiss screw caps that are produced by the traditional French manufacturer Le Parfait differ from other screw caps as their highlight is a second metal lid including a gumming (vacuum lid). Thus the screw-top jar can be used for preserving in the twinkling of an eye.
The filled jar is covered by the vacuum lid and the screw cap. During the preservation process (please pay attention to temperature and time duration!) or rather after cooling down a vaccum is generated. Releasing the screw cap, the vacuum lid closes the glass at its filling reliably. Le Parfait delivers a seperate lid opener. The vacuum lid is also available as a substitute.