Sunday, 7 July 2013

Keeping drinks cold at garden parties

Here's an idea I got from Mythbusters, which seems to work:

They say that if you put cans and bottles in a bucket full of ice cubes, although the ice is very cold, only a small part of the surface area of the container is in contact with the ice cubes and the rest is in contact with the air, which has no cooling effect.

So what you do is dissolve salt in water and put the brine in the freezer. It won't freeze solid because of the salt, but you now have sub-zero brine. When you put your cans and bottles into a bucket full of sub-zero brine, the whole of the surface of the container will be chilled.

I wasn't organised enough to put some brine in the freezer beforehand so I just chucked enough salt over the ice cubes to make them melt and - ta da - it seems to work a treat.

(Problem is that super-cooled champagne/cava/prosecco is incredibly easy to drink and the three of us taking part in the experiment got through three bottles in about half an hour. So it's probably better to use this technique for cooling beer and soft drinks.)


Morgan Charles said...

I think those "rapid-ice" cooler sleeves you can get for woine bottles work on the same principle.

Mark Wadsworth said...

MC, quite possibly. This is hardly cutting edge high tech stuff.

The Stigler said...

The rapid-ice sleeves contain some sort of gel with a lower freezing point than water, so when you take it outside, it lasts longer than ice. Plus they chill the whole bottle.

Mark Wadsworth said...

TS, brine has a lower freezing point than water, and you can't make gel or brine or ice any colder than your actual freezer.

Ralph Musgrave said...

Ice cubes have the advantage that an awful lot of heat is need to melt Xkg of ice compared to the amount needed to raise the temperature of Xkg of water (with or without salt in it) from zero degrees to ten degrees C or whatever.

So for a LONG LASTING effect, you’re better off with ice cubes.

As to the warming effect from air, that’s easily dealt with by denying air access to space between cubes: e.g. fill the gaps with water at zero degrees.

So ice cubes plus brain beats water plus salt. And if you insist in having your drink actually BELOW freezing temperature, then make the ice out of water that already has salt in it. That won't freeze till minus 2,4,6 degrees below normal freezing temperature - depending on how much salt you put in the water.

Morgan Charles said...

RM, on the basis that a good conductor of electricity is a good conductor of heat, you could put normal ice cubes into the brine, therefore increasing your reservoir of coolth, plus still being able to use spare ice cubes for putting straight into the G&Ts.