Category: ice

I was recently contacted by Dexas, a company that makes ice*ology ice cube trays, to give them a trial run. 

The company makes three versions:

• 8 cube trays
• 2 cube trays
• 2 sphere trays

The cubes are about 1.75 inches on each side, I believe the spheres are also 1.75" diameter. 

They cost $40 for 2 cube/sphere trays and $50 for the 8 cube trays

I tried them out twice, and they're good. Like all clear ice cube trays, they take advantage of directional freezing, the process I uncovered nearly 10 years ago on Alcademics. 

Like most clear ice trays, they employ an insulated container, a big tray that holds a water reservoir, and a smaller tray in the shape of the desired ice cubes.

The main difference between these trays and others is that the cube/sphere trays separate sideways, which makes them easier to remove from the silicone container than others that must be pried apart. 

They recommend that the reservoir trays be microwaved to release the cloudy part of the water so that they can be reused quickly for the next batch. I didn't try that but just ran hot water over them and this was effective, but I appreciate the easy turn-around time. 

Pros: 

• easy to use
• easy to remove cubes/spheres from trays
• make very good clear and solid shaped ice
• seem sturdy and long-lasting after a few trials

Cons:

• a bit small – 2" cubes would be better
• a bit pricey at $40 per two-cube tray
• 2 cubes at a time isn't many 

If you're trying directional freezing and still not getting clear ice, here are a few considerations. 

Know What's Reasonable.

Directional Freezing doesn't get rid of any cloudiness in ice, it just moves it toward one end of your cube/block. You will always have about 15-30 percent cloudy ice as the last part of the ice freezes (if you allow it to freeze all the way). 

Motion or Vibration. 

While your ice is freezing are you moving the container around? Does your freezer shake and vibrate? Are you opening and slamming the door shut a lot? Any sort of motion tends to knock air bubbles together, and they float up and stick to the bottom of ice as it's freezing downwards, often leading to little bubble trails and starburst-shaped groups of bubbles. The more vibration, the more bubbles/cloudy bits form.

Super Cold Freezers.

A friend of mine couldn't get his ice balls all the way clear using the thermos method. After much back and forth, we realized that he has a super fancy freezer set to super duper cold. The ice ball froze so quickly from all sides that it didn't have a chance to push the cloudy parts out the bottom of the ice ball mold into the thermos. 

In general, the warmer your freezer (but still below freezing, obviously), the clearer the ice – but you still want to be food safe (below 0 Fahrenheit or -18 Celsius). As far as I know, the Igloo cooler method should still work in a very cold freezer, but some thinner vessels will freeze from the outside-in rather than in one direction. 

Some Tips to Improve Clarity. 

If your ice is pretty clear but you've become obsessed with making it ridiculously clear and minimizing the cloudy part at the end of the block (it happens), a few things you can try are:

• Unscrew the aerator off your sink faucet (and put it back on after; it saves water waste). 
• Run it through a water filter. Even though direction freezing acts as a filter, pushing minerals and other impurities into the last part of the ice to freeze, you can reduce the mineral/impurity content by using water from the pitcher. 
• The reason I run my water through a filter is to remove chlorine/chloramine tastes in the water. I don't care about the minute improvement, if any, in clarity, but I find that if I use unfiltered water when I pop the block out of the cooler there's a big release of chlorine smell. Blech. 
• Boil the water. In my opinion, this isn't worth the effort or energy waste, but it can improve clarity ever so slightly. Boiling water should reduce trapped air.

These tips shouldn't make radical, but small, improvements in your ice's clarity. 

To read all the ice posts here on Alcademics, check out the Index of Ice Experiments.  

Ice in the freezer can absorb smells from both the freezer and the refrigerator, to the surprise of many people. Ice can also sublimate (evaporate) and shrink fairly quickly. So you can either place your ice in a sealed bag/container, and/or do the same with your food.

In my fridge/freezer situation, I don't leave any food unwrapped so that the ice never absorbs food smells. I used to stick leftover pizza in the box in the fridge and by the next morning my ice would taste ever so slightly of it, so now I put the pizza in a Tupperware-type container. There doesn't seem to be any problem with uncooked vegetables stored in there (not smelly onions or garlic or anything), but cooked food is problematic. 

For ice that you're going to be storing, I recommend either Ziplock style sealed bags or Tupperware-style containers. Those keep it sealed from sublimating and from absorbing smells. Easy. 

If you want to see just how permeable ice is, add a drop of food coloring on top of a big block and watch how it flows into the cube along invisible cracks. 

image from Ziplock.com

To read all the ice posts here on Alcademics, check out the Index of Ice Experiments.