I've always felt a little off about using crown caps that have the rubber (well, something with rubber-like properties) gasket based on possible health and environmental consequences of them. I know that an obvious solution to this would be a bale-top bottle or a keg or something, but I'm curious, are there any alternatives to this kind of cap? Would a plain metal cap without any gasket hold a good enough seal? How were caps used before the rubber gasket addition? Any thoughts on this would be greatly appreciated.
Right, I realize that eating, breathing, and drinking properly sealed beverages are all great things, I'm just wondering about other methods.
Before the plastic/vinyl liner, crowns were lined with a thin layer of cork - thus their original name - "crown corks". The cork-lined crowns were still being used into the '60's by some brewers and soda bottlers- eventually the cork was sometimes lined with a thin layer of aluminum foil-type of material. (Pilsner Urquell is last brewer I remember using cork-lined caps). I still see them unused in partial boxes when someone's selling a Prohibition era capper (niice for capping old collectable bottles but I wouldn't use them on homebrew). The metal in a crown simply acts as a crimping device to hold the actual seal (cork or vinyl) in place and keep the bottle sealed.
