Why is there (almost) always one icecube that just won't come out of the icecube tray?

June 17, 2009 6:46 AM

Why is there almost always one icecube that just won't come out of the icecube tray?

The answer is not confirmation bias. I have used a plastic icecube tray for decades, and this is a strange phenomenon I have noticed.

posted by stinkycheese to food & drink (18 comments total)

The ice cubes pop out by deforming the plastic around them causing pressure thats greater than the static friction holding them in.

When all of the cubes pop out, there is enough movement in the rest of the tray without the ice cubes so that the single cube's tray doesn't flex. No flexing means no distortion means no pressure, means its stuck.

I am not a physicist.
posted by bensherman at 6:55 AM on June 17 [6 favorites]

In a situation where some number of occurrences does not or cannot happen simultaneously, one of them will be last. This rule ("Flanders' Law") will be of some comfort to anyone picked last for a team in gym class.
posted by stupidsexyFlanders at 7:01 AM on June 17 [6 favorites]

Is the stuck icecube always in the same position, or does it move about the tray? Maybe your tray doesn't have enough flex to dislodge the icecubes in some problem spots when twisted, or some of the cells do not have the correct shape and tend to keep the cubes stuck in.

I suggest sticking a sheet of paper marked with positions on your fridge and keeping score.

You really need to do statistics on this, handwaving does not protect you from confirmation bias
posted by Dr Dracator at 7:31 AM on June 17 [1 favorite]

It may be because you are using those one-word icecubes.
Try using ice cubes. They won't stick. It may be an easier transition if you hyphenate for a bit first.
posted by weapons-grade pandemonium at 7:31 AM on June 17 [7 favorites]

I'm not a physicist either, but I'm pretty sure bensherman is right, because that's exactly what I feel when I'm trying to get that last stubborn cube out. But I wouldn't say "almost always." I suspect this happens about 40% of the time. I'm pausing here to go empty a tray...
...Stuck!
My tray is 3 columns across and 5 rows down. Column 3, Row 2 stuck.

OOO
OOX
OOO
OOO
OOO

Everybody go empty a tray and report back.
posted by planetkyoto at 7:32 AM on June 17 [2 favorites]

Just saying you've noticed it and that it's not confirmation bias doesn't rule out confirmation bias. That's the reason it's called a bias, because it's so hard to escape.
posted by proj at 7:33 AM on June 17 [2 favorites]

because you failed to warm the underside of the tray with a little running warm water. ;)

I don't know what you are talking about. All of my ices cubes always come out, but then I do the water thing or only the top half of each cube likes to come out.
posted by caddis at 7:35 AM on June 17

I'm with bensherman, but also suggest that you can work around this by simplying drinking your drink from a bucket, and using the entire tray to cool it. Consolidation of tasks results and it's undeniably more efficient.

Kidding aside... I think bensherman is probably right. You are restricting your complaint to plastic trays, not the alumnium ones with the handle, which have other issues.
posted by FauxScot at 7:40 AM on June 17

I have noticed this, too. I have 2 x 8 pocket ice trays and when I twist it to loosen the cubes, the lower left cube always sticks (I believe because I am twisting the tray with my right hand, and holding it steady with my left, so the left side receives less twisting, thus loosening). Try overfilling also. The extra water, then ice, breaks everything up nicely.
posted by heather-b at 7:45 AM on June 17

I suspect bensherman is correct.

This wasn't an issue of one ice-cube being the last to come out, it's more that I am practically breaking the plastic ice-cube tray on the counter to get it out. I worry I will wake the baby sometimes, it's so loud. Often I just give up & refill the tray over that last ice-cube because it just doesn't seem worth it.

I have tried the warm water trick but it doesn't work very well for me. I wanted to make clear at the outset that this really is happening almost every time. "Confirmation bias" is a standard answer for questions of the 'why does this always happen' variety, and I was hoping to avoid that.

Maybe I just need a different plastic ice-cube tray, who knows? But it really is standard in my experience that all the ice-cubes save one come out fairly easily, and then that last bugger is well nigh impossible to extract.
posted by stinkycheese at 7:50 AM on June 17

You cover over it?! That last damnable ice cube deserves to die! I wash him out and let him die a slow death in the sink then refill in its place, in the hopes that the next one behaves better.

Also, you could try those soft silicone ice cube trays, then you'll get each cube out easily!
posted by Grither at 8:02 AM on June 17 [2 favorites]

Er, these. Not sure why that link didn't work in my previous post.
posted by Grither at 8:03 AM on June 17 [2 favorites]

That does look like a solution, Grither.
posted by stinkycheese at 8:15 AM on June 17

A co-worker once told be that ice cubes freeze faster if you put hot water in the trays. This is of course not possibly true, but I understand that the idea may have arisen from the fact that ice usually begins to freeze around a particle, or even better, an already-present ice crystal.

If you dispense all the ice cubes from a tray and rinse it out with hot water, there are fewer particles in the tray, and certainly no ice crystals lurking in the bottom to provide a seed for water molecules to crystalize around. (water can reach temperatures below the freezing point without freezing if the crystalization process is not facilitated.)

THE FOLLOWING IS MY OWN THEORY: If you fill a tray that still has fractured pieces of ice in it, facilitating ice crystalization, the cubes will begin to form more readily, but the overall time they take to freeze will be longer, thus resulting in a less uniform crystaline composition, hence the ice cubes will break uneveny, resulting in fragments left behind which perpetuate the cycle of unwhole ice cubes. The last cube will break rather than pop out clean and whole.

So rinse out the trays thoroughly with hot water.
posted by longsleeves at 8:23 AM on June 17

A co-worker once told be that ice cubes freeze faster if you put hot water in the trays. This is of course not possibly true,

Your co-worker is thinking of the Mpemba effect, which only applies under certain circumstances.
posted by Electric Dragon at 8:37 AM on June 17

Seconding Grither: those silicone trays never have this problem because they're endlessly bendy. Also, you can get them in cool shapes like dinosaur bones and Space Invaders!
posted by Pomo at 8:55 AM on June 17

I just moved into an apartment that came with its own ice cube trays.

Let me tell you, these ice cube trays are BITCHING. The come with little non-ice making trays to dump the ice in, that fit neatly under the trays for when you ARE making ice, and no cubes stick.

Just get thinner walled ice cube trays, if it bothers you.
posted by shownomercy at 11:10 AM on June 17

Try Rubbermaid trays. They're blue. Better than the cheapo white ones, and they're still cheap.
posted by weapons-grade pandemonium at 11:32 AM on June 17