Instant Freeze

This week I did something I have always wanted to try, but never remember to do when the conditions are right.
I took a cup of boiling water outside and threw it into the air. Since it was -14 outside, it instantly turned to ice. The vapors froze and the droplets turned to snow. It was pretty cool!
I tried it again when the temperature was closer to 0 and it still worked, but was not as spectacular. I also tried it with cold and hot-from-the-tap water, but that did not work. It needed to be boiling hot.
I guess Dad was right - hot water does freeze faster.