Bottled mineral water froze in seconds on a metal bar in northern China.br br The miraculous video, shot in the city of Anshan in Liaoning Province on November 25, shows a man slamming a bottle of water onto a metal bar on the roadside, seeing the water instantly freeze.br br The phenomenon is called supercooling or undercooling, which is a process of lowering the temperature of a liquid below its freezing point and it requires the water to be pure.