Ice cubes

Here are ice cubes that live up to their name. I'm trying to get clear ice cubes. I heard if you boil the water twice then that rids the water of minerals and air that clouds the ice. I've failed three times. It occurred to me maybe water doesn't boil hot enough at altitude so I pressure cooked the water on severely high, twice each time, so that's four times in the pressure cooker and it still clouds. I'm going to try reverse osmosis water next. If that doesn't work, then I'll boil the reverse osmosis water. (twice) I'm not going to quit until I try everything. Some of these actually do come out partially clear, but not 100%.

Tovolo trays.

I learned the secret to clear ice.

It comes from clear ice that forms on a lake.

As ice freezes from the top it pushes impurities downward into the water below. The ice sheet is lifted off and it is clear. 

Clear-ice molds use this same principal. The molds have a hole in the bottom so the impurities can pass through into water below and outside of the mold. Both freeze eventually so the mold and its container must be separated. So then, for clear round ice the round mold is inside a larger square mold. It's a real production to get clear round ice and it takes a lot more space than jut the round molds. But clear ice is valued because ... because ... just because. That's why.