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M Q

wrote:

Doug Miller wrote:

... The objective is to remove heat from the can of beer as rapidly
as possible, and that will happen when the beer is immersed in a bath of
icewater. Not when it's immersed in a pile of ice.

I tend to agree.

And the reason for that is that water is a better conductor of heat than ice,

Water has a 0.596 W/mC conductance, vs 2.26 for ice. But it's hard to keep
the can completely in contact with ice, and that way, the heat transfer from
the ice is limited to the can surface. If the can is in a large well-stirred
bath of ice and water, the ice will have lots of heat transfer area to water,
and the can surface will be very close to the temp it would be if the entire
can surface were in contact with ice.

Nick

Actually, the conductance of the ice is irrelevant. What is important
for removing heat is the phase change happening at the surface of the ice.
If you could keep the ice in perfect contact all around with the beer can,
you would not need the mel****er (and there would be no room for it).
As the ice is melting and changing shape, you cannot keep it in contact.

So now the question is: is it better to fill that gap with air or mel****er?

The advantage of water: it is a better conductor of heat than air (although I
suspect that the greater effect is due to convention rather than conductance).

A disadvantage of water might occur if you are trying to lower the temperature
below 32F using a salt. In that case you would be using some of your cooling
power to lower the temperature of earlier mel****er. Also, the mel****er
would also better conduct heat from the walls of the vessel holding the mix.
Best to just drain the excess mel****er.