Clear Ice and Container Shape
Cutting Corners to Make Clear Ice

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.

In one experiment, I was waiting for ice to freeze (this is what I do with my spare time) and noticed that the ice had frozen all around the outside perfectly clearly, leaving the center full of yet-unfrozen water (and our old enemy-trapped air). So I poked a hole in the top with an ice pick and released all the water.


Then I refroze the ice to make sure it would stay clear. It did.


And I produced my first batch of perfectly clear ice. Hooray!


Now that's a sexy bowl of ice.

Conclusions: To release the air bubble in the center of ice, a straw does not work. Neither does attempting to disperse the air by using a spoon or other conducting material. But if freezing ice is stopped before completion and the unfrozen center drained, one is left with a very clear, but hollow, block of ice.

Future Experiments: Most people will not have the time to wait around until a block of ice is just frozen enough to poke a hole into. Thus it would beneficial to devise a system that releases the trapped water/air in the center of a freezing block of ice. 

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


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Adriene Crimson

Time to use the ice!
What if you put new water in the hole, little by little? A McGuyver version of that sprayer ice maker you love so...

Loren C. Pigniolo

It might be worth investigating how commercial ice-making machines are designed to operate in production of clear ice. There may be different procedures/designs for freezing block ice vs cubes as well. You are on the tip of the iceberg.

Camper English

Adriene- interesting idea. I am done posting my icesperiments for this week, but the next ones I am working on involve adding water in layers. I'm just doing it in baking pans now, but if it works (doesn't look likely) then it could be used for that. I'll keep it in mind.

Christopher Carlsson

Did you remove the aerator on your tap/faucet before you filled the containers ? One way to cut down drastically on dissolved air at the start.


Cool! Congratulations!

Ken Moorhead

For as incredibly nerdy as this topic is, I'm VERY glad to have subscribed to your RSS so I would (eventually) find information like this.

It would be more difficult and costly, but have you tried "vacuuming" the air out of the water before freezing? I wonder if one of those home vacuum-sealing appliances would be able to pull the gases out of the water. My guess is they don't have enough power...

Camper English

Chris- good point. Where I think this is all leading is a combination method of tactics to reduce air and impurities and coax the air bubble that does form to form somewhere it can be easily cut out. How much long that will take is anybody's guess...


Why didn't you just boil the water? That is the first thing that occurred to me, and by a strange non-chance the first thing that comes up on a Google search for "make clear ice"!/

Justin Chase

What if you got something that was really cold and dripped water onto it slowly forming layers of clear ice from the inside out?


Metals conduct heat and melt ice quickly, which would explain why your bar spoon experiment didn't work. Most ice machines create cubes with hollow centers, which is why they appear clear. Boiling the water first will reduce some air, but it seems that the real trick is to create thinner layers of ice.

I work for a home appliance manufacturer. The production of a clear ice maker in a home refrigerator has been the holy grail in our industry for a long time. I have seen one in production by a german manufacturer, but it might have been a prototype.

When they make clear ice in a stand-alone ice maker, they do it by creating the ice slowly in layers. Starting from the bottom and then gradually adding another layer of water and another layer of water until your cube is the correct thickness. This takes a while to do. Hopefully this will help you!


interesting article...but why not just ask a local ice sculpture person/place?


He has already tried boiling it. He reached the same conclusion I did when I tried boiling water and then freezing it, which was that it does not eliminate cloudiness from air bubbles. My guess is that this is because the water just re-absorbs air as it cools.


Ice sculpture block ice is made with giant ice making machines (I had a link once, but I can't seem to find it). The machines that make clear ice (not all ice sculpture is done with clear ice, but the machine I had seen does produce it) use a flowing water, gradual freezing method, which seems to be the standard industrial solution for making clear ice.

The puzzle here is how to make clear ice at home without a lot of money/space for a professional icemaker. This is an unsolved problem on the Internet!


No, the experiment was freezing water that starts hot vs cold. Boiling was incidental to the process.

Note that the Instructable has you starting with filtered water and boiling it twice, the goal being to remove impurities that impede the freezing process. Also note the perfectly clear ice cube at the end. Obviously, there's something to it.


have you tried making ice from water that has been left to stand for a few days? When you first fill a container a lot of air enters due to the turbulence in the water as it leaves the tap. This will slowly disappear over time - hence why you see bubbles on the inside of a glass that has been left with water in it.

Austin Liu

Here's one technique you didn't try:

take an aluminum tray, and insulate every part of it but the bottom. Cap it with a 1/2 inch thick slab of foam-core board to insulate the top. This way, it will only freeze from the bottom up, and as it freezes, it will push all the trapped air towards the top, where it can escape. The foam-core board on top will keep the top from freezing.

I will attempt this myself. It shouldn't be too difficult.

Austin Liu

In fact, there is an even better method: build a box with an open bottom out of foam core, put it on a pan or some sort of flat surface, put saran wrap inside, and cover it with another slab of foam core. That should insulate all but the bottom so it freezes bottom up, pushing all the trapped air out the top. I will also try this.

Austin Liu

One cheap way I've used to suck out a lot of the air dissolved in water is to put it in a large wine jug (like one of those glass gallon jugs of Carlo Rossi wine) until the jug is filled half-way, and to use one of those vacu-vin tops, and to suck out all the air. (You need to leave enough room to pull a good pressure drop to help get the air to bubble out.) Then, I agitate and shake the bottle to get out any remaining bubbles, and use the hand pump to suck out all of that air as well. It works rather well at getting the air out. Doesn't leave the ice perfectly clear, but it was better than plain tap water.


Try attaching a "personal massager" to the side of the container you are freezing the water in. The vibrations should keep the top of the water from freezing and allowing the air to escape with little to no cloudyness.

Don't thank me, saw it on that show!


Boiling then cooling then boiling then cooing is all it takes. Then freeze. You may try a third boil/cool. No magic and no holy grail , just do it.


Oh, and by the way, you cannot put "cold" or coldness into an environment anymore than you can put darkness into a lighted room. You can remove the light but you can not add dark. Think about it!!!!!


One more thing to ponder... you do not have to heat water to make it boil. You can just remove the pressure that is being applied to it (normally atmospheric) and it will boil without added heat energy. Boiling is boiling either way.


jono, you sound like a wanker that doesn{t want to add anything beneficila but just try to look smart on the eyes of the beholder.

Shane McKnight

So I read all of your ideas and the solution is hilarious....boil the water and then rest in in a metal two plug in vibrators underneath the pan in the freezer and vibrate on high while it's freezing...vibrating the remaining bubbles out of the water...
...and grin when you make cocktails

Camper English

I actually went to a sex store looking for a vibrator that plugs in to do this experiment, assuming battery-powered ones wouldn't last as long as it takes for water to freeze. They did not have any so I've yet to try this.


The key to get clear ice is slow freezing, just like what happens when icicles form. When freezing is too quick, air bubbles can get trapped in the ice and/or pressure builds up in the ice and causes it to fracture, hence the white cracks that you can see in typical ice cubes. Slow freezing is the key.

David Rysdam

First of all: Anyone who suggests boiling has never tried it.

Second of all: I think the straw idea is a good one and was abandoned too early. Instead of a plastic straw, which floats anyway, why not use a metal one? And to prevent it from freezing first, slightly heat it. Not sure how--maybe make a mini-pipe-warmer out of an electric hair dryer coil?

Camper English

If you follow the link in this very post before getting all sassy, you'll find I did try boiling water and that it does not work.

Second- you could be right. I don't have the equipment to make that a reality. If you try it, please share your results!

Oliver Jones

there are vibrating back massagers that plug in if that's what you want. you'd need to do some good waterproofing before submerging it.

Camper English

Good idea! I still need to do this experiment even though I've figured out a clear ice solution.


Ken, I tried that too. Using boiled water and vacuuming multiple times - doesn't work. The only thing that works is to control the direction of the freeze to force the dissolved gasses to a specific location other than the center, which is why the cooler method works.


Commercial clear-ice makers work in a similar way, though it is a stream of water steadily flowing over the frozen part. If you try to freeze in layers, just get striped ice cubes.


I do not work for, nor receive any compensation from this company, but I use their product, and it works exceptionally well.

Captain Quirk

I don't think he was being "sassy" -- I think he was agreeing with you! :-)

Boiling water doesn't work because dissolved air is NOT the problem. The problem is that when water freezes, it does so from the outside in, and it expands in the process, creating huge internal stresses that create thousands of tiny fractures and fissures which is what causes the cloudy appearance. So instead of freezing from the outside in, you need to freeze from one side to the other ("directional freezing", as you call it), stopping the process before it freezes all the way. (Of course I don't need to tell YOU that -- this is just for the benefit of everyone who thinks boiling the water will alleviate the problem of cloudy ice. It won't.)

Dark Pigen

I had a perfect Martini at Disneyland's restaurant/Bar called Carthay.
The sphere Ice Ball maker was used to make an amazing ice sphere that was as clear as glass. I was chatting with the Bar tender and he was also intrigued. So he called the company that makes the clear ice and he told me they used industrial mold vibrators. Molds for rubber, plaster or whatever often get variations of air bubbles while the mold sets. They use vibrators to release them to the surface. The ice maker cuts the top off and is left with clear ice. On ebay I found a dental mold vibrator for less than $50. Its a price to pay for clear ice. There are other methods but require more attention during the freezing process.

Camper English

Cool, I haven't heard of anywho who got a vibration method to work. Have you made your dental mold vibrator work yet?

Blue Thursday

The solution is to put a little playmate size cooler full of water in a big chest freezer. Leave the top open and let it sit for 24-48 hours. Because the bottom and sides are insulated, it will freeze from the top down. Pull out the cooler before it is frozen all the way through. The top part will be clear as the ice directionally freezes and the impurities will be in the water on the bottom. Remove the clear ice on top and chop up into glass sized pieces. Doneski.

Camper English

Correct - That's the method I uncovered here on Alcademics a couple months after this post was written 8 years ago :)

Robert Bright

Fill a pitcher with water and let it set for a day. Then as most of the air rises and escapes alot of tiny air bubbles will stick to the side of the pitcher. Using a rubber made scraper scrape the sides of the pitcher to help the bubbles raise up to the top. try not to swirl the water creating a vortex which will force the air down ( we want it to escape). do this a couple days in a row and I have had mediocre results . Not perfect but the cubes dont look to bad.

Camper English

@Robert Bright - Thanks! I figured out the trick to making clear ice later this year (this post is from 2009).
I should have gone back and put that in the beginning of this post. Here is the link to where I list the solutions:

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