When I worked as a waitress, the ice machine was a constant source of awe, entertainment and sometimes low-key horror. It was a modern marvel that could instantly turn a tepid Pepsi into a frosty refreshment—when it worked, that is. Which was … not always. One restaurant I worked at even got a German cockroach infestation inside the machine, which meant we occasionally served drinks with frozen bonus critters that thawed, then crawled out to say hi. (You’re welcome for that image.)
But the one thing that always baffled me (besides how the machine could sound like it was dying while still somehow producing ice) was this: Why did the ice cubes look like tiny frozen donuts? Why the hole in the middle? And why are restaurant cubes this way when most ice cubes are square?
Turns out, there’s a surprisingly scientific reason for that very specific shape, and it has almost nothing to do with aesthetics or doughnuts, says food scientist Bryan Quoc Le, PhD, author of 150 Food Science Questions Answered.
So what is going on with this holey ice? I asked Le and two other experts to get the inside scoop (pun definitely intended). Read on for some very cool facts. (Sorry, couldn’t help myself … again.)
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Why does restaurant ice have holes in it?
Those holes are there for three main reasons, all having to do with how commercial ice machines are designed to make their magic. “Doughnut ice” sadly isn’t their name though—most people call them hollow cubes, gourmet ice, cylinder ice, circle ice, or bullet ice. But whatever you call them, there’s serious science behind those frozen holes. Here’s why restaurants love them.
Speedy cooling
“The basic idea is the holes in ice increase the surface area contact between the ice and the beverage, thus cooling down the beverage much faster than an intact cube with no holes,” Le says. The shape is all about “maximum beverage contact,” which sounds like something James Bond would ask for but is really just about giving you your soda at its optimal frostiness level in record time because more ice is touching more of the liquid. It’s like the difference between trying to cool down a pot of soup with one giant ice block versus a bunch of smaller pieces—more surface area equals more efficient heat transfer.
Bartender Lea Miner, who uses this ice daily and is a self-proclaimed ice snob, says this “holey” ice plays an important role behind the restaurant bar. “Many cocktails are served chilled or over ice, but it looks sloppy to just pour it over a glass of crushed ice,” she says. Not to mention, crushed ice melts fast and can leave tiny shards floating in your drink—which can really reduce the experience of having a nice cold drink. Instead, bartenders put the hollow bullet ice in a shaker with the drink, shaking the drink down to bone-chilling perfection, then strain it into a glass filled with slow-melting, picture-perfect cubes. “Cocktails should never be sad, watery soup,” she says.
Fast production
Restaurants don’t have time for delicate, artisanal ice cubes that take eight hours to freeze. They need an avalanche of ice, and they need it fast. Enter the commercial ice machine—and the top reason restaurant ice has holes.
These industrial beasts work nothing like your home freezer, Le says. Instead of slowly filling little molds and waiting for them to freeze, commercial machines use an evaporator system that sprays water onto a super-chilled metal surface—usually a cylinder. As the water flows over it, it freezes in layers around the outside. When the ice reaches just the right thickness, the machine gently warms the metal, and the hollow cylinders drop into the bin below, ready to be scooped into drinks.
(But for the love of all things holy, never scoop with an actual glass. That was rule No. 1 at every restaurant I worked in. Because if the glass shatters inside the ice machine, you can’t tell what’s ice and what’s glass—and the whole thing has to be shut down and cleaned. I’ve seen it happen. It’s tragic. And involves a lot of mopping.)
The perfect cooling-to-water ratio
Restaurant owners aren’t just being extra—they’ve discovered that these holey ice cubes offer the ideal balance of cooling power and drink volume for fountain soda, lemonade and other quick-serve drinks. “The holes mean you get plenty of ice-to-liquid contact for quick chilling, but you’re not displacing so much drink volume that customers feel shortchanged,” Miner says.
Less water usage
Another reason restaurant ice often comes with holes? It’s more efficient and, yep, cheaper. “Hollow ice uses significantly less water per ice cube while still providing good cooling power,” says Chris Hockings, a commercial ice machine technician and engineer with 35 years of experience in refrigeration. That means restaurants can serve up chilly drinks while cutting down on water usage—a win for both the planet and the utility bill.
Increased safety
Bonus: These hollow cubes are also rumored to be less of a choking hazard. While we couldn’t find any official studies to back this up, the theory checks out. The hole might allow more air to pass through, and since these cubes melt faster than solid ones, they’d cause a blockage for a shorter amount of time. In theory, anyhow. But it’s worth thinking about because nothing ruins a nice dinner out like someone choking on their drink.
What’s the origin of this hole-y ice?
It’s not like the first ice inventor woke up and thought, You know what this needs? A hole. The tube shape became popular with the invention of modern commercial ice makers in the mid–20th century. Because the machines were designed to freeze water quickly and eject it easily, these smooth-sided, doughnut-shaped cubes fit the bill. This ice could be produced rapidly, stored efficiently and delivered with superior cooling performance, Le says. This wasn’t an accident; it was engineering at its finest.
The design became so successful that it spread throughout the commercial food-service industry, becoming the standard for restaurants, bars and other establishments that needed reliable, efficient ice production.
Where else will you find ice with holes in it?
Besides your neighborhood Chili’s, you might spot hollow ice cubes in some surprising places.
On airplanes
Yes, the ice in your in-flight ginger ale may also have a hole. Not because of altitude, turbulence or weight (though hey, every ounce counts up there), but because of where it comes from. While some airplanes may have onboard ice-making machines, it’s more common for them to get bags of ice made elsewhere—either at the airport with the same commercial ice machines or through a third-party vendor. That said, you might want to think twice about eating ice on an airplane for contamination reasons.
At hotels
Many hotel ice machines use similar commercial-grade tech, especially the kind you find down the hall in that suspiciously loud closet, Hockings says. These machines are built for speed and volume—same as restaurants. Hotels appreciate the quick cooling properties for guest satisfaction; plus, the ice stores well and doesn’t clump together as much as solid cubes might, he adds.
In home freezers (occasionally)
Some higher-end fridge models may have automatic ice makers that produce small tube-shaped cubes, but those are pretty rare, Hockings says.
Why doesn’t this shape pop up more in everyday life?
Short answer: It’s not cost-effective. “The reason domestic fridges produce crescent-shaped cubes essentially boils down to the cost of appliance production,” Hockings says, adding that commercial ice systems can run in the tens of thousands of dollars. “For in-freezer ice machines, manufacturers need an ice-making solution that is simple, reliable, easy to mass-produce, and cost-effective.”
Your fridge isn’t trying to underachieve—it’s just doing the best it can with what it’s got. Here’s how it works: Instead of having its own dedicated ice-making system like the big commercial machines, your fridge piggybacks on the freezer’s cooling power. Water fills a curved metal mold (which gives it the crescent shape) and freezes; then, a heating element warms the tray just enough to loosen the cubes, and a rotating arm knocks them into the storage bin.
And that crescent shape? It’s not just for looks. “The curved base allows the cubes to eject more easily from the tray,” Hockings explains. He adds that crescent cubes displace more liquid, reduce splash when pouring and (bonus!) make your glass look fuller. Now you know why your soda at home always feels a bit more generous than it actually is.
Should more of us be using this type of ice?
The answer depends on your priorities. For bars and restaurants, it’s a no-brainer: Hollow “tube ice” is fast, efficient and great for high-volume service. “It cools beverages faster due to the increased surface area and uses less water per cube,” says Hockings. It also looks sleek and stacks neatly, which matters when you’re filling hundreds of glasses a day.
But at home, you have more options. “There’s really no ‘winner’ when it comes to ice shapes,” Hockings says. “Each one has its benefits.” That said, he says crescent ice is the MVP of versatility: “It cools well, looks good, doesn’t splash and works in both bags and ice dispensers.”
Le agrees that there’s no universal winner. “There’s no optimal shape for an ice cube—each has its own uses and optimal conditions,” he says. “In my own household, we prefer large spheres and cubes, as they help keep beverages cold for longer without diluting it so rapidly, compared to smaller ice configurations.”
How can you get holey ice at home?
If you’re determined to bring restaurant-style ice to your home bar, you do have options. Some higher-end countertop ice makers can produce bullet-style ice with holes, though they’re significantly more expensive than standard models. You can also buy bags of commercial ice from restaurant-supply stores or some grocery stores.
But regardless of whether you like your ice cubes square, spherical or with a hole in the middle, just know that you’re witnessing peak beverage engineering. Behind each chilled drink is a story of physics, efficiency, cost-saving genius and maybe a little bartender flair. And hey, now you’ve got the perfect weird fact to share at your next dinner party. Just maybe skip the part about the cockroaches.
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Sources:
- Bryan Quoc Le, PhD, food scientist, author of 150 Food Science Questions Answered and founder of Mendocino Food Consulting; phone interview, June 19, 2025
- Chris Hockings, commercial HVAC technician with Best Ice Machines; email interview, June 19, 2025
- Lea Miner, mixologist and bartender; in-person interview, June 23, 2025
- Cheap Air: “Why you should never eat ice on a flight”
- Best Ice Machines: “Types of Ice”
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