Loosen cage by rotating the tab 6 half turns. Loosen it enough to fit over the lip of the bottle but don’t take it off yet. Be sure to keep your hand holding both the cork and cage in place now that it’s no longer secure.
Hold bottle at a 45° angle and start to rotate the base of champagne bottle while holding the cork and cage firmly. You’ll find this much easier and safer than trying to rotate the cork/cage.
Apply increasing pressure to hold the cork/cage as you feel the cork start to push out with the bottle pressure. Not to worry, if you do this process slowly, the cork will pop out with just a little ‘fssssszzz’.
2 Secrets to Opening Champagne:
Source: Wine Folly