How to Make Crystal-Clear Blocks of Ice

How to make crystal-clear blocks of ice in your own freezer.

All you need is:
Expanding insulating foam
A plastic container, such as a glass or pitcher
Plastic wrap and/or foil

Category:

Howto & Style

Tags:

• clear
• ice
• science
• making
• freeze
• freezer
• blocks

[RafaelMarrero86]

I'm pretty sure the easier way to do this is to boil the water first before freezing to create clear ice. Also, If you want to remove all of the air bubbles you would have to have the container be vibrating while freezing.

[spcutler]

@RafaelMarrero86 Boiling actually doesn't work very well at all--that was one of the first things I tried! You can get some of the bubbles out, but you still have the problem of the ice in the middle of the block expanding and cracking everything around it.

Boiling probably works well for small ice cubes, though. I needed larger blocks to work with my ice ball maker.

[RafaelMarrero86]

@spcutler I see. I know when they make the big blocks for ice sculpture's they use boiled filtered water in a big square mold on top of a vibrating platform. Once the water is almost frozen they hollow out the center and refill it with filtered water to make it clear and without air bubbles.

Also, what do you use the ice balls for?

[spcutler]

@RafaelMarrero86 Hmm, that makes sense. I've also heard that pumps are used to recirculate the water. At any rate, on the small scale this works pretty well.

The ice balls are for looking pretty in a nice glass of scotch.

[kliu08]

would you mind posting a picture or video of what happens if you put the completed clear ice blocks back into the freezer? I want to see how much further freezing increases cloudiness