Alcademics

Clear Ice and Container Shape

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Camper English

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Today is Ice Day on Alcademics, so stay tuned for more exciting coverage of my ongoing experiments to make clear ice in my home freezer.

So far, I've tried:

So far I haven't achieved… anything, but I'm gathering information that should help in the future. In recent experiments, I found that ice freezes from the outside in, which is sort of obvious, but it's important because that's where all the air is trapped that makes the majority of cloudiness in ice. So I wanted to try some different container shapes to test how and where the air bubble forms. 

In a vertical container, such as these Vietnamese take-out soup containers I've been using, the air bubble forms toward the middle-bottom. (I've set the ice upside-down in this picture.)

Vertical1s

Whereas in a flat horizontal container such as a lasagna tray, the air bubble forms in a layer across the bottom of the pan.

Icepan1s

The experiment continues after the jump.

Side view of the cloudiness mostly at the bottom:

Cloudybottom1s

I thought then that I might minimize cloudiness in a vertical container by using a very tall one. I will have to go shopping for something in that shape. To test the horizontal container, I went back to the all-for-a-dollar store and bought an aluminum foil turkey pan. I had to bend it to get it to fit in my freezer. It froze like this:

Turkeypan1s

And the ice looked like this:

Bigice2

There appears to be just as much cloudiness in the giant pan of ice as in the smaller pan. I had hoped that there would be more cloudiness towards the center of the pan with more clarity at the edges, but this does not appear the case- the air bubble just spreads out flat across the bottom.

Conclusions: The amount of air/cloudiness in ice appears proportional to the amount of water in the container, but by changing the shape of the container we can slightly manipulate where that cloudiness will form. 

The next test, coming later today, is to use this information to our advantage.

An index of all of the ice experiments on Alcademics can be found here.

Comments

8 responses to “Clear Ice and Container Shape”

  1. Scott Avatar
    Scott

    I filled and froze a spare Camelbak bladder once and it resulted in a strangely shaped but remarkably clear block of ice. The [rpblem was in removing it without cutting the bladder, but have you tried freezing water in a vacuum container where all air has been removed?

    Reply
  2. Camper English Avatar
    Camper English

    I tried but not with a fully vacuum sealed container. I would assume this would be at least partially successful, and would help determine how much of the air in ice is trapped within the water rather than is absorbed while freezing.
    In any case, not sure if you’ve seen the later experiments here on Alcademics, but click here’s the best way I’ve found to make ice:
    https://www.alcademics.com/2010/08/a-homemade-giant-crystal-clear-ice-cube-tray.html
    and for all the ice experiments, you can click the ‘ice’ tag:
    https://www.alcademics.com/ice/

    Reply
  3. LB Avatar
    LB

    The new version of a foodsaver has a vacuum attachment for containers. This would be a good at home solution to the vacuum question. I would suggest letting the water incubate under vacuum for 24 hours to give it plenty of time to off-gas before freezing.
    I also have a container recommendation. I’m picturing a cup/bowl/box that is thin walled at the bottom that tapers gradually to be thick walled at the top, with an insulating cover over the top. The idea being that the less insulated bottom will freeze first and push bubbles to the top while freezing and all the way to the lid.
    This design might be hard to find since it isn’t the most sturdy for carying things. Maybe a potter or glass blower can make one. or you could shave the outsides of a styrofoam box.

    Reply
  4. Camper English Avatar
    Camper English

    I would love to try it under vacuum sometime, but have a feeling it will produce ice that is stuck to the bag in which it is frozen, thus making it hard to remove.
    On a similar note, I tried a version of your container recommendation: I filled a huge ziplock with water, put it in the Igloo cooler, and turned it upside-down in the freezer. That way it should freeze from the bottom-up. Unfortunately all the folds in the bag made it hard to tell if it even worked.
    But basically I’d like to try making a container that fits snugly inside the cooler and using it upside-down.

    Reply

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