In the lab one of the cool things is to take a 100 mL pyrex tall-form (Berzelius) beaker about half full of DI water and set it on top of a little slab of dry i

In the lab one of the cool things is to take a 100 mL pyrex tall-form (Berzelius) beaker about half full of DI water and set it on top of a little slab of dry ice which is at the bottom of a small bowl. Then pack some crushed dry ice around the beaker and the water starts to freeze quite quickly from the outside in. When the frozen water is about 5mm thick, remove the beaker, pour out the liquid water and return the beaker to the dry ice nest until it's quite a bit colder. The ice in the beaker continues to shrink and can then be removed from the beaker "mold" as a shot glass made of ice. Caution: do not handle it with bare hands, nor consume any contents at this point until it is no longer very far below 0. Best to allow these ice glasses to "warm up" to a comfortable temperature in an ordinary freezer before use. It will then withstand pre-chilled liquor for a number of minutes after serving.