Wife put some of those long skinny ice pop things in the freezer (in a vertical orientation between the wires of the shelf) since it was supposed to be hot.
This morning we found none of them had frozen. After a quick sanity check to make sure the freezer was working and everything else was cold, we grabbed one and inspected it. After shaking it rapidly froze in front of us, with fine grained crystals expanding out in all directions from many nucleation sites (probably bubbles from shaking it).
The same thing happened to every other ice pop in the pack. Textbook example of supercooling.
Anybody else ever seen this before? Are there additives in ice pops that promote supercooling somehow, either as a primary function or a side effect? I thought supercooling was mostly something that happened in extremely high purity liquids like distilled water.