Back in Napoleon's day, French officers needed to open their champagne bottles but couldn't be bothered to actually do it by hand. Supposedly, their solution was to take out their trusty swords and slice the things open, racking up some serious style points in the process. But you don't have to be a French cavalry officer — or even have a sword — to do it at home.
Choose the Right blade
You're not actually slicing the glass – in reality, it's more like you're sharply knocking the top of the bottle and letting the champagne's pressure do the rest. It's more of a break than it is a slice. So you do need a blade of some sort, but it doesn't have to be sharp. In fact, it probably shouldn't be. Using your prized chef's knife will work, but you'll dull the edge in the process.
Instead, pick something that you don't mind dinging up a little bit. A real deal champagne sabre will work like a charm and look damn cool, or you can just reach for a hefty kitchen knife.
Get the Bottle Ready
Ideally, you want to use real French champagne, which has a thicker glass bottle, though any kind of sparkling wine will do so long as it's sufficiently carbonated. You need all that pressure to help the top come flying off when you strike it.
You also need the bottle — the neck in particular — to be thoroughly chilled. Stick the bottle upside-down in an ice bucket for a half hour, or at least keep it in the fridge until you're ready to start swinging.
Swing away
Ok, here's the tricky part.
First, you want to hold the bottle so that the seam in the glass faces up. That's the line you're going to follow when you swing, since it's the weakest part.
Hold your blade at about a 45 degree angle to the bottle. It has to firmly catch the ridge at the top of the bottle when you swing, so you don't want it angled too flat.
Then all that's left is to swing. Do it quickly and forcefully, following through to get a clean break. And be safe while pouring – it should be fine, but make sure that no errant pieces of glass fall off the bottle's newly sliced glass rim and into anyone's glass.