freezing big blocks of ice

[michnix]

is there anyone who has some experience with freezing big blocks of ice in a way that they don't crack??
My boss got the idea in his head that he wants some ice sculptures at the buffet- he even bought an ice stand, slightly bowl-shaped with a sink in the middle and two fancy lights on the sides that change colours....
nice idea and all, but nobody in our kitchen has experience with ice sculpting (not to mention spare time to do this)...
so he bought a mould where we just can pour the sculpture (a 1,2m high clef) and freeze it. the problem is, that the ice cracks almost every time- no problems as long as it keeps together, but more often than not the cracks go all the way through the ice and it falls apart when we open the mould....
any suggestions??? We got a tip to cook the water before pouring- but this seems no big help....
thank you for your help
david

[Rivitman]

The water must be kept circulating as it freezes. You need circulation pumps. Ice carvers will often sell blocks to other carvers and chefs wishing to do their own work.

[ALynch]

You need to temper the ice. Let it sit under refrigeration (38-41F) for about 4 hours before you unmold it. Also if it cracks into large pieces you can use bubble gum remover to freeze them back together. This is stuff that comes in aerosol cans that is meant to freeze bubble gum off tables and such. It will freeze the large blocks of ice back together.

Good luck
Let me know if this works

[michnix]

the bubblegum remover idea sounds good- the problem is it cracks while still in the freezer and in this plastic mould...

[ChefMarco]

sound like you have hard water
try the following 1Tablespoon Of salt per 1/2 gal of water mix well and freeze

also try spraying out the mold with cooking spray it will prevent sticking

[michnix]

no, we don't have hard water at all- our dishwashing machine is 20 years old and not a trace of lime... but I'll try the salt anyway... maybe it helps

[kuan]

You're from Norway? Just cut a chunk off a frozen lake.

We used to just buy ours. 40 bucks US each #300 block.

[michnix]

well, I suppose I could take a tour up to the glacier on the other side of the fjord...
buying such stuff is not that easy (cheap), here in the middle of nowhere- 4hours drive from the nearest big city... I don't know if hte big boss wants to invest that much in a lump of ice......