Comments on: Frozen Jello.

Question: Frozen Jello.

five fresh fish — Thu, 23 Feb 2006 17:07:25 -0800

Imponderables: Many (most?) liquids ("things"?) will crystallize when cooled slowly. Why not Jello™?

Further to the question, cold-quenching or flash-freezing reduces crystallization. Does Jello do anything interesting if frozen using liquid nitrogen? Could one nail it to a tree?

By: aubilenon

aubilenon — Thu, 23 Feb 2006 17:27:55 -0800

I don't think regular jello has a crystal structure. If you freeze it for real, like putting it in a freezer, I'm pretty sure that the water in it WILL form ice crystals and it will become a proper solid.

Try it yourself!

By: puke & cry

puke & cry — Thu, 23 Feb 2006 17:30:23 -0800

I can vouch for that.

By: ikkyu2

ikkyu2 — Thu, 23 Feb 2006 17:36:06 -0800

I think one of the problems is that a lot of folks are taught about the three states of matter: gas, liquid, solid - as if that were all there is.

Pure compounds can exist as gases, liquids, or solids, and they phase transform. During the transformation from liquid to solid, most - but not all - compounds crystallize. Water crystallizes, forming ice.

However, there are amorphous phases - black carbon is amorphous carbon; diamond is crystal carbon. Window glass is amorphous silicon dioxide; rock crystal (quartz) is crystalline silicon dioxide.

When compounds mix, even more bizarre states of matter are possible, such as gels, sols, solutions, aerosols, colloids, aerogels, and who knows what else. Jello, unsurprisingly, is a 'gel' - water packed into a protein matrix, in this specific case.

Hopefully the above jargon terms would help you in Googling or Wikipedia-ing for more knowledge. (I have no idea what happens when you dip Jello in liquid nitrogen, by the way.)

By: Megafly

Megafly — Thu, 23 Feb 2006 18:17:09 -0800

Of course Jello can freeze, and the ice crystals then melt when you thaw it out and make an runny mess.

I know this from experience when I was to impatient to wait for the Jello to cool in the fridge.

By: PurplePorpoise

PurplePorpoise — Thu, 23 Feb 2006 20:19:49 -0800

Jello isn't a fluid.

Jello is a matrix of polymerized long-string proteins with a high water content.

You can flash-freeze jello in lN₂ and it'll get brittle. Defrost it and it'll turn into goop (the protein polymer gets denatured).

Lyophylizing (slowly dropping temperature while applying a vacuum) jello-like substances is kinda cool. It kinda shrinks and deforms a bit but you end up with a (very) brittle chunk of, "foam" (although there aren't any holes).

By: neda

neda — Thu, 23 Feb 2006 20:48:01 -0800

You're talking about already gelled Jello, right? Or do you mean un-gelled jello shots you've impatiently stuck in the freezer? If it's just-mixed powder & boiling water you're talking about, it's not yet a gel, it's a sol. Sticking set jello in the freezer is something different that sticking still-setting jello in the freezer.

If you've just poured in the boiling water, and you stick your jello pan in liquid nitrogen instead of the fridge like you should, the water won't yet be trapped in the gelatin matrix, and that untrapped water can freeze (like the mess megafly had to deal with). Normally in the jello setting process, the disordered gelatin strands in the hot water form an unordered network of proteins (with water trapped inside the pockets) as the solution cools.

If it's already set jello, I wouldn't know, but it looks like purpleporpoise does.

a tangential note: gel colloids inhibit freezing crystallization of stuff you put them in (which is one of the reason gums are added to commercial ice cream and frozen desserts--though gums are sugar branches, not peptides like in gelatin).

By: state fxn

state fxn — Fri, 24 Feb 2006 00:37:10 -0800

Purpleporpoise: how and where did you manage to lyophylize jello?

By: mumeishi

mumeishi — Fri, 24 Feb 2006 07:50:08 -0800

Excuse the interruption, but this discussion, particularly the answers, are fascinating. Was talking with someone last week about sodium acetate heat packs, supercooled non-crystallized water, and all that. Been a while since college -- this is making me miss it.

By: PurplePorpoise

PurplePorpoise — Fri, 24 Feb 2006 10:18:59 -0800

state fxn - I was working in a place that researched antibiotics and they had an old machine for lyophylizing stuff. Office party, beer, jello - one thing led to another.

mumeishi - there's a hypothesis (admittedly semi-crackpot) that the "vacuum" of space is a supercooled liquid and that there's the possibility (given a high enough energy/whatever concentration somewhere) that the whole shebang will crystalize.

By: five fresh fish

five fresh fish — Fri, 24 Feb 2006 10:38:51 -0800

The lyophylizing bit is keenly interesting. I have access to a bell jar and vacuum pump.

Raspberry-flavoured Aerogel, here we come!

By: PurplePorpoise

PurplePorpoise — Fri, 24 Feb 2006 10:40:12 -0800

It's very brittle.