Tag: ice cubes

Directional Freezing, as a Patent Law Exam Question
As readers of this site know, I figured out "directional freezing" – the process of making clear ice by controlling the direction in which water freezes – in 2009 and first posted it here on Alcademics.

I had always assumed that I couldn't patent the process because it's something that happens naturally (like how ponds and lakes freeze), but perhaps could have patented a device for producing clear ice cubes had I been entrepreneurial enough. (As you know, many such devices now exist.)

Well, this question became an exam question from Jason Rantanen, Professor at the University of Iowa College of Law.

On this post on the website Patentlyo.com, he talked about the test as he proposed a hypothetical:
Camper English was the first person to discover that clear ice could be produced in a home freezer by freezing the ice in a directional manner. English published these findings on a weblog on December 28, 2009, a copy of which you were provided in Appendix A. English immediately filed a patent application that contained the following claim.

I claim:
1. A method of producing ice comprising freezing water in a directional manner in a home freezer.
Analyze the patentability of the claim under current patent eligible subject matter law.
The rest of the test question involved the Wintersmith's clear ice maker. Keep reading the post for more info an an image from the patent application. It's pretty interesting.

Rantanen didn't provide the answer on the Patentlyo website, but he did give me permission to post a rough technical explanation of the answer, with the understanding that the below does not constitute legal advice:

The full answer involves application of an analytical framework that the U.S. Supreme Court articulated a few years ago in a case called Alice v. CLS Bank. Basically, you first ask whether the patent claim is "directed to" an unpatentable concept like a law of nature or physical phenomena. If it is, you then ask whether the patent claim adds an "inventive concept": basically, something that transforms the claim into something more than just a claim to natural law itself. A formalistic addition isn't enough: saying "I claim the process of risk-hedging, done on a computer" or limiting it to a particular technological field, such as ice-making, isn't enough.

In this case, claiming the concept of directional freezing would fail the eligible subject matter requirement since it's a natural law or physical phenomena. Even limiting it to being done in a home freezer is very unlikely to be enough of an inventive concept. However, claiming a specific process for making clear ice could be sufficient. For example, a claim to "a method of producing clear ice by placing water in vessel that is insulated on every side except the top and placing that ice into a home freezer" would likely be enough to satisfy the patent eligible subject matter requirement. There's a neat recent case that my students would have been aware of called Rapid Litigation Management v. CellzDirect that involved a process of freezing and unfreezing liver cells. The Federal Circuit (the Federal appeals course that hears appeals in patent cases) held that that particular method did constitute patent eligible subject matter.

The Wintersmith device on the other hand strikes me as a pretty clear application of natural principles. I doubt anyone would be able to mount a serious patent eligible subject matter challenge to that patent.

All that said, there's still the issue of whether or not the invention is new. If someone else described the same process then the process wouldn't be patentable. But newness is a different issue that's governed by a different set of rules.

Got all that? Sure you do. Me too :)

In any case it's awesome that after all these years I got an answer for a lingering question about The Blog Post That Launched A Hundred Ice Cube Trays.
January 8, 2018
Making Clear Ice with the Clearly Frozen Ice Cube Tray
While I'm not going to get in the habit of testing out every clear ice cube maker on the market, I decided to try out the Clearly Frozen tray because they sent me one.

This ice cube tray uses directional freezing, the process to make clear ice first described here on Alcademics back in 2009. This particular system is pretty much the same as in this blog post about poking holes in silicone ice cube trays and using directional freezing to ensure the part inside the tray is clear. The difference is that in the Clearly Frozen device, the shape of the 'cooler' is custom made to fit the ice cube tray and retaining tray.

The device is just three parts: a 10-cube silicone ice cube tray (makes 10 2-inch cubes at a time), a plastic retaining tray to hold the cloudy ice beneath the tray, and the foam insulated box that enforces directional freezing. You put it together, fill it with water, and leave it to freeze. My timing was perfect at a little over 12 hours of freezing – there was still plenty of unfrozen water in the plastic tray so it was easy to separate.

Pros:
- Makes more cubes than most clear ice cube trays on the market – ten 2" cubes
- More space-efficient relatively than others – it takes up a bunch of space, but you get more ice out of it than with other clear ice makers
- Costs less than others- $25 including shipping
Cons:
- I have no complaints for my first attempt, but I do have some doubts about its long-term durability. The interior clear tray is quite thin and I could see it cracking. 2019 update: They have updated the interior tray with a much thicker and more durable plastic, so it seems this tray will last a long time.
Personally I will probably continue to to make my ice one big Igloo cooler at a time, because I enjoy the process of breaking up an ice block and don't care that much about having super-square ice cubes. But of the commercial products I've tried, this one has a low price and some nice features.
December 26, 2017
More Fun with Ice: The Time Bomb

The fun with ice continues! In ongoing experiments freezing things in ice, I decided to try freezing food coloring in the middle of an ice cube. Then when the ice melts, the coloring will release and change the drink.

Click on the link below to see how I did it and what happened.

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October 28, 2010
Making Clear Ice Without a Cooler
In a set of experiments, I showed that you can make clear ice by controling the direction of freezing. The container I've been using for this is an Igloo cooler. When using it, the ice freezes from the top-down and all the cloudiness in the ice forms at the bottom of the container rather than in the middle of the block.

I wanted to show that you can do this without a cooler as long as you have some sort of insultation that accomplishes the same thing as the cooler. In this case, I chose a bigger pool of water as an insulator.

As a control I froze a plastic take-out container of water in the freezer.

As usual, it is cloudy over a large area, mostly in the center. This is because the water freezes from the outside-in. The last part of the ice to freeze contains air and any impurities, and is cloudy.

So then I took the same container and put it into a larger container. The smaller container sits on cubes to keep it off the bottom of the larger container.

Both containers were filled with water to about the same level. The purpose of this is to use the outer container of water as an insulator. The water inside the smaller container would then freeze only from the top-down instead of outside-in, because the water surrounding it would freeze later (because it is so big).

The results show that this worked- the cloudy part of the ice was the last part to freeze at the bottom of the container.

What this means:
- Directional freezing works as long as there is an insulated jacket around the container. The ice freezes only from the top-down, pushing the cloudy part to the bottom.
- This property could be exploited to make an ice cube tray that makes cloudy-on-the-bottom ice. Picture, for example, an ice cube tray that was insulated with a jacket on the sides and bottom.
- So now I can do more experiments to make an insultated jacket that is practical.
An index of all of the ice experiments on Alcademics can be found here.
October 22, 2010
A Homemade Giant, Crystal Clear Ice Cube Tray
As you're probably aware, I've been dabbling in experiments making clear ice at home. [update: An organized index of ice experiments on Alcademics can be found here.] The way I've found that works best is to freeze ice in an Igloo cooler with the top off. (Please read the post before you tell me to boil the water in the comments- it doesn't work.)

This is now how I make all my ice at home- I haven't used trays in months.

Now I am working on ways to best carve ice and also trying to create an ice cube tray that will work in this directional freezing system. I found a method that works that I need to perfect.

Here's what I've done.

I went down to The Container Store and purchased these plastic gift boxes. They're 2 inches by 2 inches wide (4.5 centimeters) and around 5 inches tall (11.5 cm) with the tops off.

These I put in my Igloo cooler. I've done it with the open top of the container facing up, and also facing down. Facing down works better, actually, because the air in the rectangles gets pushed out the bottom. Facing up, you get a 1cm cloudy patch at the top of the cubes. No big whoop.

Then I fill the cooler with water and freeze it. It comes out as a block of ice with the cubes stuck in it.

These separate surprisingly easily from the block.

Also surprisingly easy is how the ice pops out of these plastic containers. I just leave them upside-down for a couple minutes and the ice cubes slice right out.

As you can see in the above picture, there is a little bit of cloudiness when the trays are left with the open part facing up. I repeated this experiment with the open part facing down and there was less cloudiness. Either way, there isn't much to worry about as it can be cut off when cutting these big long cubes down to 2 inch by 2 inch by 2 inch ones.

Conclusions:
- These ice cubes are fricking awesome.
- I need to try it with cutting off the bottom of the containers so that they're a rectangular tube rather than a box.
- I think this is actually scalable to make an ice cube tray with some tweaking.
- Hooray!
An index of ice experiments on Alcademics can be found here.
August 27, 2010
Ice Meets Chainsaw

Ice nerds got a real treat this Tuesday, for Andrew Bohrer from Seattle was guest bartending in San Francisco along with Amanda Womack from Cask.

He brought chainsaw Thursday to the city in order to chop up giant blocks of clear ice from an industrial ice maker into big cubes that could be further cut into ice balls.

Keep scrolling for videos of hand ice carving… or click here for an index of all of the ice experiments on Alcademics.

First they cut slices off the big blocks, then cut those into long rectangles. Then they cut those into cubes.

Click below for the videos.

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August 12, 2010
Clear Ice Blocks at Home in an Igloo Cooler
This post describes how to make a clear block of ice using a picnic cooler. Since I first wrote it in 2009, I have figured out a lot about ice, but this was the defining post for what would become known as "directional freezing." What is Directional Freezing? (the basic theory behind clear ice).

An index of all of the ice experiments on Alcademics can be found here. It's also a great place to start.

Before I figured this out, I tried many other experiments.

Early experiments were:
And I had success with:
- Releasing Air Trapped in Ice
- Cutting Corners to Make Clear Ice
I also learned some ways to cut ice into big chunks.

Now I am trying to refine what I call the Pond Method, the concept that if we freeze water from the top down only (and not outside-in), all the trapped air that makes cloudy ice will be the last to freeze on the bottom of the container, rather than in the middle.

In the last attempt I used a collapsible beer cooler. I had good success in getting clear ice, but found it really hard to get the ice out of a cooler.

This time I tried freezing water in a hard-sided plastic Igloo picnic cooler. Initially I left the cover closed, but after two days it had only barely started to freeze (a good sign for its insulating abilities) so then propped the cover open.

After a few days when the water looked almost completely frozen and I could see some cloudiness forming at the bottom, I removed the cooler from the freezer. I turned the cooler upside-down and waited for the ice block to drop out of the cooler. Presto! It was ready.

There was a little unfrozen water at the bottom of the block (with only about a centimeter of ice covering it). This was easy to drain.

Then I just cut off the bottom cloudy part and had a big chunk. Easy!

Once again, the secret to cutting ice is to score it about a centimeter with a knife or saw, then chip it away with an ice pick and hammer.

Conclusions:
- I'm really surprised the cooler didn't crack after the ice expanded, but maybe it didn't because there was a little unfrozen water remaining.
- This Igloo cooler is a totally workable vessel for making clear ice blocks in my home freezer. Hooray! Luckily it is of a shape that allows for easy removal of the ice block.
Future experiments:
- In this first experiment with the cooler I set the freezer temperature on the lowest setting. I'll see if this matters for clarity or if I can use the high setting for faster freezing.
- I also want to try a disposable Styrofoam cooler (if I can find one this winter) just because there is no worry if it cracks, and this is the most reproducible vessel for other people to try at home.
- I should attempt to find a flexible insulating material that can be made into other shapes, such as a tall and skinny shape (thermos?) that would more easily fit in the freezer and can make smaller cubes.
Here are more clear pictures of the ice pulled out of the cooler with some of it unfrozen, and it after smashing off the unfrozen part.
December 28, 2009