Category: ice

Directional Freezing, Freeze Distillation, and an 1890 Story About Ice Purity

Ice nerds will recall that directional freezing is a method for making clear ice by forcing the water to freeze in one direction, rather than from the outside-in as in a typical ice cube tray.

It's also pretty similar to, if not the same thing as, freeze distillation – using freezing to separate liquids. Freeze distillation is the method by which early American applejack was made: take a cider and freeze it, scoop off the frozen ice, and then you have a more concentrated cider, higher in alcohol. Keep doing this and eventually you get something pretty high proof.

This was also the process used by BrewDog to make their high-proof Tactical Nuclear Penguin beer.

Experimenting with directional freezing shows that when using the process, the clear ice freezes first and the air and any minerals in the water are treated as impurities, pushed away from the point of freezing. But as many people have found out, it treats everything not pure water in the same way – when you try to add food coloring or a flavoring to the cooler in a directional freezing system, unless you put a ton of it in the color is treated as an impurity and your ice still comes out clear. (The bottom/last part to freeze will be gooped up with the color/flavor. )

Jim Blakey of the ClearlyFrozen ice cube tray found a story in JAMA, the Journal of the American Medical Association, that talks about how clear ice less polluted than the lake water from which its formed. I'd assume this is for the same reason.

“clear ice from polluted sources may contain so small a percentage of the impurities of the source, that it may not be regarded as injurious to the health."

Here's the story.

The original reference in Google Books is here.

January 9, 2018
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
Ice Tips in Southwest Airlines Magazine

If you're traveling in December on Southwest, you may notice an illustration of an ice ball with a strawberry in it. That's based on a real strawberry inside a real ice ball, that you may have seen here on Alcademics.

I don't see the story online, so I'll post it below.

For more information on how to make awesome ice balls with stuff inside them, check out this post and this post, and of course the Index of Ice Experiments here on Alcademics.

Thanks to writer Michael Cook for writing the story and thanks to my friends who spotted it in magazine and snapped pictures for me!

December 13, 2017
That Time I was a Resident Ice-Pert

Last week in New York, I was the "resident ice-pert" for the Hennessy Le Grand Voyage. The experience was a walk-through super-Instagrammable introduction to the production of the cognac.

There was a rain room representing the vineyards, a color-changing still room, an aromatic barrel room, and an interstellar sort of tasting room, all before one arrived in the lounge where I was stationed on press preview day.

It was pretty cool. Here is a story about it from The Latin Times, and here is the press release on PR Newswire.

And here is another awesome picture of me.

Photo by Dave Kotinsky:Getty Images for Hennessy

November 21, 2017
Boiled Versus Rested Water Clarity with Directional Freezing: A Comparison
The main water factors that affect ice clarity in an ideal environment:
- Gasses in water
- Minerals/other impurities in water
Factors of the freezing environment that also impact clarity:
- Rate of freezing (warmer temperatures better)
- Shape of container, which impacts whether the last part to freeze will crack the ice (as it does in a typical ice cube tray)
- Jostling/moving of the cooler in a home directional freezing system (cooler with the top off) as this causes bubbles to form earlier
I've been studying each of these factors carefully, as I may be contributing a section on the science of ice to the Oxford Companion to Cocktails and Spirits (which hasn't been edited/approved yet, and isn't due out for a while so don't get too excited).

One factor that has always confounded me is the gasses in water. We know from observation that gas in water becomes trapped in ice in the form of bubbles, whether that's in the center of an ice cube or the bottom of the block using a cooler in the freezer.

Most kitchen sinks have aerators on them that add more air to water, so that's a factor. But there are also lots of theories (boiling water, freezing then melting then refreezing) that are meant to minimize the air in water.

My issue has always been: If trapped air in water is water's natural state, then if you boil the water to eliminate that air, wouldn't air just be re-absorbed into the water when it returns to room temperature?

Dave Arnold in Liquid Intelligence asserts that you should boil the water, put it in your cooler, let it cool a bit, and then put it in the freezer. I was doubtful that this actually helps, but Dave Arnold is usually right, so I finally decided to test this.

Click on the image below to expand it greatly.

Experiment

For the first block of ice, I boiled tap water briefly, put it into the cooler, let it cool down for several hours, then froze it on the highest (warmest) setting in my home freezer.

For the second block of ice, I used tap water that I poured into the cooler, let it set out overnight, and froze it the same way. The theory of letting it sit overnight was that the air bubbles introduced via the sink aerator and pouring water from one vessel to another would fizz off naturally.

For the third block of ice, I put tap water through a Brita filter, and was generally extra careful to not introduce air by splashy pouring. (I was hoping the filtering and light handling would further reduce aeration.)

Results: The fully cloudy, opaque (unusable) section of of the block is slightly reduced in the boiled water vs. unboiled. If I were making ice in an industrial capacity using coolers, it probably wouldn't be worth the time/effort/heat to boil the water to produce rather than getting it done 5 hours earlier and having a half an inch less usable ice.

However, the amount of thin streams of bubbles in the clear part, which look okay but not perfect when cut into cubes (though a bit more dramatic in pictures), seems significantly reduced in the boiled water block.

Conclusion: Boiling water before freezing in the directional freezing system does appear to improve the clarity of ice, in particular by eliminating bubble streams in the section of ice just before the solidly cloudy final bit.

It does not improve ice clarity on its own more than directional freezing does in the first place, and therefore won't replace directional freezing (and boiling water was the first experiment I did in trying to make clear ice eight years ago), however it can make directionally-frozen ice better.

It seems the natural aeration of water poured from the sink is reduced, though certainly not eliminated, by boiling the water before freezing it.

A future experiment (not sure if I'll actually do it) would be to let the boiled water cool down to the same temperature as the unboiled water before freezing, though I doubt this would have any impact.

How will I change the way I make ice at home? I will not. I try to use filtered water, frozen in a cooler, removed after 2-3 days so the cloudy bottom part hasn't formed at all.
October 9, 2017
New Business Models for Large Format Cocktail Ice Providers

Large format cocktail ice providers have been around for a while, but now big cube/sphere/spear providers are branching out into new shapes, sizes, making machines, and pushing into retail.

In a story for SevenFifty Daily, based in part on my talk at Tales of the Cocktail, I wrote about what several companies are doing to bring more larger clear ice to more people.

August 8, 2017
Make Amazing Frozen Liquor Bottle Displays using Directional Freezing

Using just a cooler, a makeshift stand, and a bottle you can make cool-looking displays for home, parties, or the bar.

If you're just getting started into ice nerditry, you'll want to check out the Index of Ice Experiments, where you can get a definition of Directional Freezing and see other fun projects.

I previously shared how to do this on this post.

In short: inside an insulated cooler, lay a bottle atop a small riser of some sort (I used a plastic box lid) so that the bottle is raised up a few inches off the bottom.

Fill the cooler with water (tap water is fine) so that it covers the bottle. Leave the top off the cooler and let it freeze. In my home freezer, that takes 3-4 days. Thanks to Directional Freezing, the top part of the cooler (so the front part of the bottle) will be clear, while the bottom (back of the bottle) will have all the cloudiness in it.

You can see from this back view that the plastic riser is still stuck in the back. From the side view, you can see that thanks to directional freezing the top part of the block is super clear (so you can see the front of the bottle), while the back is cloudy. It turns out the cloudy part actually makes a nice backdrop.

Remove it from the cooler than your display is ready to go. I've done this at parties (putting some LED candles in the ice beneath the standing block) and it was a huge hit.

Check out all the ice experiments on Alcademics at this link.

June 26, 2017
Freeze Liquor Bottles Inside an Ice Tube for Better Bottle Service

Using just a cooler, a tube, and a bottle you can a super funky display for your party or for bottle service at your bar.

If you're just getting started into ice nerd stuff, you'll want to check out the Index of Ice Experiments, where you can get a definition of Directional Freezing to see why this works, and see other fun projects.

I originally developed this technique for the bar Whitechapel, which was looking to do a unique Martini cart with frozen bottles.

Simply put a bottle inside a tube of some sort (this is a metal utensil holder like you'd see at a salad bar) and fill both the tube and the rest of the cooler with water. Directional Freezing will take care of making the top part of the ice clear. The cloudy part is all around the bottom of the bottle. If you wanted it 100% clear around the bottle, you'd simply put it on a short riser inside the tube.

Then freeze it (with the top off the cooler) and pull it out.

I did this again with a bottle Zucca as I'm using it for a talk. I no longer had the metal utensil container so I put in a plastic pitcher. I wouldn't say it is the ideal container given that is has irregular sides, but it did the trick for proof of concept.

The bottle is a bit problematically tall for my freezer – I almost couldn't get the cooler out!

Cheers!

Check out all the ice experiments on Alcademics at this link.

June 22, 2017
Fire Inside Ice (Okay, Fireball inside an Ice Ball)

For years, bars including Chicago's Aviary have been serving drinks inside hollow ice balls. The procedure to make one is easy, at least in theory.

Freeze a balloon or an ice ball mold filled with water for a few hours. An ice shell will form on the outside.

Poke a hole in the ice ball and dump out the water. Refill with a (very well chilled) cocktail. Some bars do with a syringe so that you don't have to open a real hole in the ice ball.

Then serve it. I did this at home and thought it would be fun/funny to create Fire Inside Ice – so I filled by ice ball with Fireball cinnamon whiskey.

Then for a bit of a show I filmed dropping it in slow motion. Enjoy.

June 14, 2017