This little party trick is guaranteed to impress, and you don't need any special materials, just a decent freezer and a bottle of beer. Emory University physicist Sidney Perkowitz, the author of the forthcoming book Hollywood Science, says the phenomenon at work here is most likely supercooling - a process by which water can remain in a liquid state below its freezing point. It's a delicate balance, though, as the water will turn to ice given the slightest shock.
If supercooling is the culprit, the hidden scientist in this video most likely left the bottle in the freezer long enough for it to drop down below the freezing point - some other sites recommend about 30 minutes. Next, the shock of slamming the bottle on the table jolts the beer, and this added energy forces it to crystallize into ice.
Of course, it's hard to say for sure what's happening in this clip, and the many other frozen beer related videos posted on YouTube, because we don't have all the information. The best way to test the idea would be to try it yourself. I'd do the same, but I don't believe in waste.—Gregory Mone