Cork closures have been perhaps the most important. Cork is light, compressible, hermetically, inexpensive, plentiful and stable. Corks have long been in use for closing glass bottles, and still are. Ordinary cork closures (stoppers), however, are unable to withstand the buildup of internal pressure, except where the pressure is not too great and when they are used with bottle having small openings, such as in wine and champagne bottles.
The diameters of the openings of glass jars used for preserving fruit and vegetables are so large that a fitted cork would be easily pushed out. Even for small openings, it was necessary to develop holdown devices, such as clamps and wire fasteners, when high pressures were expected, as in the bottling of beer. The crimped metal crown with cork liner was an effective closure for beer and soda bottles. However, aluminum screw-caps are now used in nearly all cases.
Glass Containers
