Fun with Supercooling
Several months ago, I bought a pack of 700 mL Poland Spring sport cap water bottles. I put it into the freezer to get it really cold. When I went to get it after several hours, it wasn’t frozen, but when I jostled the bottle, it froze right before my eyes, a mass of slushy crystals slowly moving up the bottle.
I realized that the water must have been supercooled, and that as soon as I jostled it, the crystallization began, and once primed, grew rapidly. I did it again. I called my kids over to see it. My 6yo declared it to be “the coolest thing I’ve ever seen with water!” Considering the waterfalls and geysers he’d seen the prior summer, that was no small praise!
I did some poking around the internet, and found the following amazing video on Youtube:
I tried to replicate it, but the water would always crystalize in my bottle before I got to pour it. And then something happened and the conditions in my freezer stopped being perfect for supercooling. The other day, I took a bottle of water out of the freezer after it had been in overnight. It was still liquid and I knew it must be supercooled, and sure enough I shook it and got the cool instant slush thing going. So today, I put in another bottle, and just now, we were able to replicate (but not videotape) the YouTube experiment! Really cool!
This page talks more about supercooling water, and explains that for it to work, you need very pure water in a very smooth container. So, it’s no surprise that bottled water is ideal for this.
I tried a few other sizes of water bottle when I first discovered this, but found that the 700mL bottles worked best. So, although I get no kickback from Poland Spring, I do recommend their 700 mL sports bottle if you want to try this. Oddly, they are not “smooth” from a human point of view — the bottle has bumps and indents to make it attractive and easy to grip. Anyhow, I encourage you to give it a try. If you do, note that once regular ice crystals have started to form, it’s too late. The water needs to be all liquid when you start, to get the cool instant freeze effect. If you try too early, and nothing happens, just put it back in the freezer and try again later.
Here’s another page with some discussion of supercooling bottled water.