4 ms·
The difference between the types of ice is similar to the difference between graphite and diamond: same atoms, different arrangement and different crystal struc
by lmkg 17y ago
The difference between the types of ice is similar to the difference between graphite and diamond: same atoms, different arrangement and different crystal structures that are thermodynamically favored at different pressures.
Tangentially related: I've heard that if you want to freeze someone with cryogenics, you need to drop the temperature very quickly to far below normal freezing, so that you get a different type of ice crystal. I'm not entirely sure what the difference is (I'm not even sure this is 100% true), but I suspect whatever harm you're avoiding is related to why frozen food doesn't taste as good. If a chemist, biologist, or cryogenist could correct me, I'd love to hear the details.
- DrSprout 17y agoAlton Brown's explanation on Good Eats of how to get good frozen strawberries effectively said that if you freeze them slowly, you get jagged ice crystals which slice membranes and cause them to turn to mush when you defrost. If you do it quickly it creates smaller, smoother crystals that leave the structure intact.
- noilly 17y agoYes- larger crystals + expansion --> puncture and break cell walls --> not good when you're defrosted. Tangentially, this is why ice cream cooled with liquid nitrogen is so smooth
- vl 17y agook, where can I try ice cream cooled with liquid nitrogen?
- Robin_Message 17y agoThe Fat Duck in Bray, run by Heston Blumenthal -- http://www.thefatduck.co.uk/ http://www.thefatduck.co.uk/ Heston is awesome. We just did a series on TV where we made, amongst other things, edible wallpaper as the desert course, so all these celebs were licking the walls...
- blogimus 17y agoHe also explained (on Peachy Keen) that if you add some sugar (being hygroscopic) to the fruit (making a sugar syrup), the sugar will help hold some of the water in the cell walls helping to reduce the size of the ice crystals.
- nooneelse 17y agoOver in the cryogenics discussion groups they don't even like you to use the word "freezing". Bad for PR and all. "Vitrification" is the going term.