How to Keep Water From Freezing

Written by

A bottle of water midway through freezing after being hit.

Illustration of a cube of ice with interior colored and labeled in light blue and exterior colored and labeled in dark blue. Text reads, "Ice crystal formation"

Illustration showing that ice crystals below a critical size melt back into the supercooled water and above a critical size, grow.

When supercooled, water can remain a liquid even below its freezing point. As explained in this Minute Physics video, this happens because of a tug-of-war between effects in the water. Generally speaking, having impurities in the water or smacking the bottle will shift that battle enough for freezing to win out. But it’s possible–theoretically, at least–to create a situation where supercooled water can never freeze. (Video and image credit: Minute Physics)