Super Cool!

Went to a Science evening for teachers earlier in the week and picked up a few fun experiments. Tried this at home with my kids and was pleased that it actually worked. The water in the bottle is below zero degrees celsius and is super cooled. When poured out of the bottle onto an ice cube it freezes back up towards where it is being poured from. You can see clips of it happening on you tube. Something to do with nucleation, but need to read up a bit more as I don't really understand the Science behind it. If you want to try this at home, here's how:
1. Put a layer of crushed ice into the bottom of an ice bucket and sprinkle 5 teaspoons of salt over it
2. Place a small sealed bottle of mineral water on top of this layer then fill all the way up to the lid of the bottle with crushed ice (leaving only the cap visible.
3. Put another 5 teaspoons of salt on the top, then stir another 5 teaspoons of salt into 100ml of water and pur this over the ice and leave for 25-30mins
4. Finally, take the bottle out and carefully pour the water out over an ice cube. (be gentle with the bottle as shaking it will cause all the water to turn to ice inside the bottle!)