Today I learned about supercooling, where a liquid can get below its freezing point without ice forming.

I found a half-drunk bottle of coke in the construction site that was still liquid. As soon as I moved it, the whole thing instantly turned to ice!

@aaronpk I remember doing a science experiement in elementary school involving several 2 liter bottles of generic cola from the local store and a very cold day (I think it was 22ºF/-6ºC?) doing exactly this in our schoolyard. Very fun, and very cold.