This is a great party trick, or great if you just want to pretend you're a wizard or a water-bender. You can instantly freeze an entire bottle of water. Grant Thompson put together this awesome video to explain how its done.
The secret is supercooling the water first. To supercool something, it has to reach a temperature below its freezing point while staying in a liquid form. Normally when water drops below 32 degrees Fahrenheit, it freezes and turns into ice.
But if the water is pure enough and there aren't any imperfections in the container holding it, the water will get stuck in its liquid state. That's because ice crystals need what's called a nucleation point in order to form. This nucleation point can be any kind of impurity in the water, like a speck of dust. Then, the ice crystal is the starter for more ice crystals - expanding the crystals exponentially.
This supercooled liquid state is not very stable either. All it takes is a jolt to align water molecules in a way that make the ice crystals start forming. They fill the entire bottle in seconds:
YouTube/Grant Thompson
You can also start the freezing process by dropping a piece of ice into the water. The ice cube acts as a nucleation point because ice crystals like to pack themselves onto an ice crystal that's already formed. You can see how dropping a piece of ice into a glass of supercooled water makes the whole glass freeze in a few seconds.
YouTube/Grant Thompson
You don't even have to drop the ice cube all the way in. All it takes is touching the very tip of a piece of ice to the water and the ice cube will freeze in place:
YouTube/Grant Thompson
It works the same way if you pour the supercooled water on top of ice. The ice crystals pack on top of each other as you pour and you can make an instant ice tower:
YouTube/Grant Thompson
Add some flavoring and make your own instant snow cone:
YouTube/Grant Thompson
You might have to experiment a little to find the ideal time to leave your bottles in the freezer: the time will vary depending on how cold the freezer is and how big the bottles are. We tried it previously with some sodas and the bottles froze unevenly and didn't give us the awesome water-to-ice immediately effect.