I recently bought some gold foil. I knew it was thin, but this is really thin. It’s actually kind of astonishing that anything solid can be this thin and still hold together somewhat. It breaks apart with no perceptible effort, and yet does hold its own weight.
I would like to hang strips of foil in water, which is then frozen. I use a technique that results in extremely clear ice, and I’ll send the frozen slug through my ice ball maker, so the result should be a ball of ice with a shiny gold strip going through it. That’s the idea, at least.
The trouble is that surface tension alone is enough to rip the foil to shreds. I’ve managed to cut and manipulate the gold, and hang it on a wire, but as soon as I dip it in the water, the surface tension pulls it down and breaks the ribbon, leaving foil shreds floating on the surface.
Any ideas for achieving this? The result has to be usable as edible ice, so I can’t add a bunch of soap to the water or whatever. I can remove the top layer of the ice, so I could possibly add a layer of something as long as it didn’t mix with the rest. Or maybe there’s some pouring technique that I can use? Currently I’m starting with a glass of water and dipping the foil in, but it doesn’t necessarily have to be in that order.
What you need is an edible surfactant. Remember rubbing your fingers on your forehead and then swirling them around in the beer bong so that greasy college face would knock down some of the foam? Maybe spraying some Pam across the top of the water?
Some quick googling says lecithin, alcohol and glycerine may also work for you. But, if it were me, I’d probably sprinkle some pepper on some water, shoot some Pam at it and see what happens…cuz the Pam is the closest to me, but the experiments should be pretty easy.
Also, you could double or triple the leaf to make it a bit more durable (maybe? I’ve never handled it).
ETA, keep in mind that the very heavy gold will probably sink when you break the surface tension. You may be better off finding a way to keep it still. Maybe partially freezing the water, then setting the leaf in. What about somehow finding a way to set a wire/paperclip in water/partial ice, setting the leaf on that, then pulling it back out after?
I’ll have to play with it a bit more–it’s possible that adding more layers would help. It’s hard enough to handle that folding is likely to be tricky. And I have a suspicion that it wouldn’t help much. There is literally no detectable force required to pull the stuff apart. It can hold its own weight because, being so thin, it has no weight, but I doubt I could lift a 1 cm^2 piece of paper on a 1-cm strip. I’d bet that even 10x the thickness would barely make a difference.
Other surfactants could be interesting–in particular alcohol, since this is intended to go in alcoholic beverages. Definitely worth a try. Pam would be interesting if I could remove the oily residue.
How about freezing a layer (of water) completely, adding the foil on top of it, then drizzling in more water on top of that?
If even that’s too much abuse, freeze a layer, add the foil, let it melt a little bit, refreeze?
How is the gold foil packaged/shipped? Could the entire “unit” of whatever be submerged, then the foil unrolled or unsheeted already under water? I can’t imagine that would be less destructive, but I’m running out of ideas.
The clear ice process I use doesn’t really allow for that, though that does give me a new idea–freeze two blocks, then sandwich the foil between them. The thin water layer between them should stay clear. Definitely worth a try.
The foil comes layered in folded paper. I think it must be dusted with cornstarch or something because the foil doesn’t stick to it, whereas it does stick to just about everything else. It may be possible to dip the whole paper strip in and remove it later, but the paper would interfere with the hanging wire and I’m not sure how to deal with that.
Ultrasonics might be worth a try.
If you have access to an ultrasonic cleaner, you could see if the sonic energy would reduce the surface tension without tearing the foil apart.
Ultrasonics–didn’t think of that at all. I do have an ultrasonic cleaner.
I tried some quick experiments and it definitely helped, in that I was able to easily get the initial dip going, and it didn’t immediately pull the strip into the surface. But it jostled things around enough laterally that it eventually ripped apart.
I also just tried some experiments with layering the foil on the ice. This actually works really well! I can get a nice solid strip laid down just by pressing the paper down on the flat ice surface. The paper peels away with no problem. Haven’t yet tried merging it with a separate block, but I don’t anticipate that being difficult.
The short answer is that you need to freeze from the top down. To accomplish this, you insulate all sides of your freezing container except the top. Remove the ice before it has frozen all the way to the bottom–stop it about halfway. If you don’t, the bottom half will trap all the air and other nasty bits (you can cut this part off, but it’s a pain).
Since I needed a custom block size, I used spray expanding foam (for home insulation). I used a plastic cup and sprayed the foam all around it. But if you just need a big block, you can just stick an igloo cooler in your freezer with the lid removed.
Boiled water, distilled water, etc. have no effect at all. Unidirectional freezing is the only household technique that works (there are other industrial processes that work, but aren’t practical in the home).
That’s very interesting because intuitively you would think freezing from the bottom up (by insulating the top and sides leaving the bottom exposed) would give you better results because the air would be “pushed out”.