Post #665029 by Limbo Lizard on Thu, Jan 24, 2013 9:39 PM

The trick to making clear ice is to heat the water till it's boiling. Let the temperature drop off just a bit, then pour it in your ice cube trays, molds, whatever, and put in the freezer. Apparently, this releases much of the trapped air, which otherwise "whitens" the ice.

I guess it's sort of like how humidity in the air condenses out as dew, when the air becomes too cold and dense to hold that much water vapor (the "dew point"). Similarly, as the temperature of the water approaches freezing, it can no longer "hold" all the the dissolved air, and it is "squeezed out" in lots of tiny bubbles that give the ice a cloudy, white appearance. Drive out the air with boiling, then quickly freeze,and you get clear ice.

Edit: MDM and I were apparently responding at the same time... and making the same "Mr. Wizard"
point. But I took longer, because I had to go make a drink, in the middle of my post, and I always over re-write and edit myself, before hitting, "Submit".
(You remember right, Mike - it's true.)

[ Edited by: Limbo Lizard 2013-01-24 21:55 ]