Cold water freezes faster than warm

Dear Matthew Alice: A friend of mine insists that an ice cube tray filled with warm water will freeze faster than cold water would. This smells like an old wives’ tale, but I thought I’d better check with you on it. — Steve Terry, La Mesa

Good advice any time a query strikes, Steve. You’ve gotten ’94 off to a fine start. There are two schools of thought on this topic. I side with you and say that cold water will always freeze faster than hot water, and the old wives, once again, are full of it. In rebuttal, your friend will probably trot out an old Scientific American article that reported an experiment comparing the cube-forming rates of water near the boiling point and water around 150 degrees F, which is still pretty hot stuff. The near-boiling water formed cubes, in some cases, 10 minutes sooner. The explanation had to do with the faster evaporation rate of near-boiling water that (1) causes heat to be carried away faster and (2) leaves less water in the tray to be frozen. Somehow this was touted as proving that hot water freezes faster than cold water. Seems to me it just proves that extremely hot water freezes faster than very hot water, which is pretty weird but hardly the same thing.

So to get ’94 off to a scientific start here at the Matthew Alice Experimental Cryogenics and Video Rental Institute, we broke out some new cube trays, filled them with tap water at various temps, set them into the freezer compartment of the lab’s wheezy Hotpoint, and waited. Take it from us, cold water freezes faster than hot. Our results may have been tainted by the three dozen homemade tamales we’d stowed in the back of the freezer for emergencies, but we don’t think so. We just think cold water freezes faster than hot, especially in the typical home environment, where trays of common tap water share space with frozen peas and Popsicles, no matter how Scientific American chooses to massage the data.