Category: ice

Carving Big (and clear) Ice Cubes

After much experimentation I have found one method to make big clear chunks of ice. That method is to put water in a cooler in the freezer, then chop off the top clear layer. Now the trick was to get this into useful sized cubes for glasses.

*Update 2021: A better post on cutting up clear ice is here.

Starting with the slab of ice (this one about three inches thick),

I used a heated bread knife to score the ice just about 1/8th of an inch,

Then tapped the scratch in several places with an ice pick and found it separated really easily.

And I got the whole thing chopped into long spears.

I use these really long ones in a tall glass

and scored and cut the rest of the spears into big fat cubes.

Hooray! Time for a drink.

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

December 2, 2009
Clear Ice Blocks from the Fridge
In my ongoing experiments trying to make clear ice in the refrigerator, I first tried:
And had success with:
- Releasing Air Trapped in Ice
- Cutting Corners to Make Clear Ice
Then theorized about the pond method.

The next step was testing this pond method (trying to freeze ice from the top-down rather than outside-in). To do this, I needed an insulated container on all sides except for the top. My first attempt was with a collapsible beer cooler:

I filled it with plain tap water and let it freeze for three or four days. The container expanded as it froze so the ice was rather difficult to remove. At the end, the block still didn't completely freeze, but as we've learned in earlier experiments the last parts to freeze are where the ice gets the cloudiest. It was also cloudy toward the center but I think that's because I gave the cooler a squeeze in the fridge before it was frozen.

The next task was to cut off the cloudy parts so that only the clear ice remained. The first time I did this with a saw. This took a long time and as I learned later was probably not necessary.

But it worked!

Part Two: Just a Bit Off the Top

Since I wasted so much of this large block I wanted to try a simpler method: Freezing it from the top down and trying to just pop off the top.

Once again I filled the cooler with water and froze it, for just a couple of days this time. When I pulled it out of the freezer the water had mostly froze from the top down, though there was a light shell of ice around the shape of the cooler. Thus to get the ice out, I smashed in the sides of the cooler and pulled off the top. It was a bit easier than the entire block to remove from the cooler, but not easy per se.

This slab was about four inches thick and wonderfully clear.

The next trick would be trying to cut it down into smaller cubes. More on than in the next post.

Conclusions:
1. To make a big slab of clear ice, start with an even bigger slab of ice and cut off the rest. At least for San Francisco water, the shape of the container matters more than anything else- boiling, filtered, or distilled water.
2. My collapsible cooler isn't heavily insulated, so the water does partially freeze from the bottom and sides and a better insulator would be ideal.
To do:
1. Find a better insulated container to maximize the "pond effect" so that water only freezes from the top down.
2. Figure out how to efficiently cut the ice into big cubes.
An index of ice experiments on Alcademics can be found here.
December 1, 2009
Another Clue to Ice Clarity: Slow Freezing Like a Japanese Pond

The other night a friend of mine told me that she read something about clear ice, which as you may recall is a topic of interest of this blog. Naturally I forgot what she said (we were at a bar, remember) but the next day I found the following email I had sent to myself:

"Clear ice old japan sawdust"

The amazing thing is that when you put that into Google the very first story it comes up with is what I assume is the exact thing my friend was talking about. In this story on natural ice (popsicles) in Japan, a person in the story gives a quote that could prove useful.

Masao Yoshiara, the fourth-generation president of the company, said: "In Nikko, the daily lowest temperature in winter averages around minus 10 C, ideal for making crystal-clear ice.

"If it's colder than that, ice can be made quickly but it is not solid enough. Here, ice grows 1 centimeter thicker a day. When ice becomes about 15 centimeters thick over half a month, we cut out ice blocks. If an ice block is thicker than that, it contains cracks."

Minus 10 degrees Celsius is 14 degrees Fahrenheit. I don't know the temperature of my home freezer, but it's worth investing in a thermometer to find out. Perhaps slow freezing equals clearer ice.

The other factor we'll have to consider about pond ice is that the bottom never freezes. Thus the air that is a major factor in cloudy ice is still in the warmer water below the surface layer of the ice.

This is another strategy I've been considering in attempting to get clear ice in the freezer: if I place a good insulator at the bottom and sides of the water container that doesn't cool down nearly as fast as the water (for example a super thick glass bowl, or a pan of ice that sits on a stone surface), will that cause all the air in the water to migrate to the bottom and freeze last?

This reading inspires a lot more ice experiments to come. I'm glad I emailed myself from the bar.

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

November 19, 2009
Does Freezing Water in Layers Make Clear Ice?
Here's a new edition in my ongoing ice experiments. So far, there experiments have been:
With successes in:
- Releasing Air Trapped in Ice
- Cutting Corners to Make Clear Ice
So far my conclusions have been that (at least with my San Francisco water), temperature and filtering have less of an effect than trapped air that migrates to the center of the freezing cube. Thus I am trying to minimize this effect.

In this experiment I froze ice in layers in small lasagna pans to see if we had a maximized surface area, hopefully no air would get trapped in the ice and form cloudy parts. Apparently some commercial ice machines such as Kold Draft spray an upside-down mist of water in layers, so this would be the home approximation of that.

I tried this experiments with tiny layers, medium layers, and large layers in the same sized pan, the difference being that I added more water per layer. I let the water freeze before adding another layer.

As you can see, none of the layers turned out clear:

(Tiny layers, medium layers, and large layers left to right.)

The small sized layers were made only adding a couple of ounces of water at a time, so I can't get much smaller layers than these unless I use a spray bottle.

We'll have to call this one a failure. Freezing water in layers does not appear to make clear ice, just ice with smaller layers of trapped air.

Below is a closeup of the layers for your ice ogling enjoyment.

An index of all of the ice experiments on Alcademics can be found here.
November 19, 2009
Cutting Corners to Make Clear Ice
In an ongoing set of experiments I've been trying to make clear ice at home. I've tried:
With some success on the last one. While what would be ideal would be to produce one giant solid block of perfectly clear ice, I haven't figured that out yet. However if the ice is going to be used to shake with or for cooling individual beverages, you don't need a giant block- just big chunks.

There is a way to accomplish this by cutting corners. And tops and bottoms. We've seen how the air bubble makes the cloudiest part of the ice in the center in vertically-frozen water, and mostly along the bottom of horizontally-frozen water.

And I've also found that horizontally-frozen water usually has an edge of very clear ice.

So with my ice pick, I just cut off the clear edges separated the top from the cloudy bottom
of the pan ice (easier than you'd expect, as the cloudy ice breaks off easily), and cut around the cloudy middle of vertically-frozen water to end up with a big bowl of clear ice.

Conclusions: You can make clear ice by cutting around cloudy ice frozen in large blocks. However, you waste about 85% of your ice, and a lot of time.

An index of ice experiments on Alcademics can be found here.
October 23, 2009
Making Clear Ice by Releasing Trapped Air
[update: after this post, I figured out the trick to making clear ice – check here for the solution.]

Finally, I've got a minor success in my clear ice experiment to share. So far in an attempt to make perfectly clear ice in my home freezer, I've tried:
Noting that water freezes into ice from the outside-in, leaving an air/water bubble that forms the cloudy part of ice, I sought to devise a way to either change the way ice freezes, or to release the trapped air while the ice was freezing.

First I tried laying a bar spoon diagonally through the water. The theory was that the metal of the spoon might conduct coldness into the center of the ice so that the ice would freeze more evenly. The intended result was a dispersed air throughout the ice rather than just in the bottom/center layer.

But alas, the intended result did not happen. There does appear to be more air dispersed in the ice, but still the majority of it is in a layer along the bottom.

Next I tried inserting a straw into the center of a tray of ice to see if the air would escape through the straw. The plan was flawed to begin with, as water would probably just freeze inside the straw so no air could get out.

In reality the freezing ice pushed the straw up so that it was only inserted about half an inch into the ice by the time it was fully frozen. This had no effect on the amount of cloudiness.

For something that did work, keep reading after the jump.

(more…)
October 23, 2009
Clear Ice and Container Shape
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.)

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

The experiment continues after the jump.

(more…)
October 23, 2009
Does Carbonated Water Make Clearer Ice than Still Water?
This is another in my ongoing experiments to make clear ice. So far, I've tried comparing:
Someone in the comments mentioned hearing that carbonated water would freeze more clearly than still water. As most of the cloudiness in ice appears to come from trapped oxygen, this didn't make sense to me, but I figured it couldn't hurt to try.

I froze equal amounts of still water and carbonated water and this is how they came out:

The carbonated water is on the right, and it sure as heck isn't clear. It's got kind of a fun texture with lots of air bubbles in it, but that doesn't get us anywhere for the purposes of this experiment.

Conclusion: Carbonated water does not make clearer ice than still water.

An index of ice experiments on Alcademics can be found here.
October 23, 2009
Nice Ice in the News

The Associated Press released the following story on ice today, with a quote from your favorite icesperimentator Camper English. The whole story is here.

SIP: Bartending trend calls for nice ice, baby

By MICHELLE LOCKE
Associated Press Writer

SAN FRANCISCO (AP) — Erik Adkins spends a lot of time on ice.

As general manager of the Heaven's Dog bar in San Francisco he's very particular about what ice goes into his cocktails, preferring hand-carved chunks for slow-sipping drinks and oversized clear cubes for lighter concoctions.

And that's just the tip of the ice trend.

Driven by the same quest for perfection that elevated bread, cheese and wine to objects of desire, ice has entered an epicurean age, coming in new shapes and sizes.

Then I get the closing quote:

On the other hand there's Camper English, a San Francisco-based writer and cocktail expert, who has blogged about his search for clarity, melting and refreezing ice at home to see if that decreases cloudiness and experimenting with distilled water.

So far he hasn't been too successful, but that hasn't curbed his enthusiasm.

"Ice is one of the fun projects that cocktail nerds can play with at home," he says.

He'll go to some lengths for a chill thrill.

"One time I caught myself asking a bartender to see their ice when I was making my drink order," he recalls, "because it was going to matter to me."

Read the whole thing here and see the Index of Ice Experiments on Alcademics here.

October 23, 2009
Does Hot Water Make Clearer Ice Than Cold?
I have been doing experiments at home to try to get the clearest ice possible. So far my experiments have compared:
- Distilled vs. Tap water
- Multiple melting and freezings of water
I have not yet had success. Will the third time be the charm?

(*Update – You might want to skip to this index page to see conclusions reached after many experiments.)

This time I compared hot water to cold water to see which would freeze more clearly. The theory is that hot/boiled water has less trapped oxygen in it, and thus will freeze clearly because there will be less air bubbles.

As I previously saw no significant difference in ice clarity between using tap vs. distilled water, I began with unfiltered tap water. One batch of water I left at room temperature. The other batch I boiled for several minutes. I put them in the freezer while the hot water was still hot. Here is what happened on three separate attempts:

The cold water actually looks a little more clear, but this could be because when the center of the hot water finally froze, it burst. I can't guess why this is because it's not like I have a super refrigerator that freezes ice in ten minutes.

Another theory about why the first experiment failed is that as the hot water cools down in the freezer, it reabsorbs oxygen and acts just like cold water. To test this, I repeated the experiment, this time covering both plastic tubs with the lid before freezing.

Here the hot water ice looks slightly more clear than it did when it was uncovered. However, I'm not seeing a significant difference in hot vs. cold water, though the covered hot water may be just slightly clearer.

Conclusion: Hot water does not freeze significantly clearer than cold water, even when the vessel is covered to reduce oxygen re-absorption.

In all of these ice experiments so far, the major cloudy factor in the ice has not been cloudiness throughout the ice, but a cloudy spot in the center of the ice. This spot is assumed to form due to the order in which ice freezes, from the outside-in. The oxygen migrates to the liquid part (in the middle) until it is the last part to freeze. Kold-Draft ice machines produce wonderfully clear ice cubes in part because they freeze the ice in layers- water is sprayed in layers from the top down, so that oxygen is never trapped.

Is there a way to freeze ice in a home freezer similar to a Kold Draft machine? Can we manipulate the way water freezes or change the shape of the container? Can we vibrate the container or stir the water so that the surface stays liquid and freezes last?

We shall see, in future ice experiments.

*Update – For a solution to the ice problem, see this post for a method that works. Also, an index of all of the ice experiments on Alcademics can be found here.
October 23, 2009