Jewish Festivals: Opening Metal Bottle Caps

You may not open metal bottle caps on Jewish festivals if a metal ring will be left after doing so. You may break that ring or simply open the bottle before the Jewish festival (or simply open the bottle and reclose it such that when you open in again, no metal will be broken).  
Note If you need the contents for a Jewish festival (such as if it is a bottle of wine), you may ask a non-Jew to open the bottle for you.  But if it is wine that is not cooked/mevushal, the wine will become non-kosher once opened and handled by the non-Jew.