Cooling with stones

[flamminggimp]

Hi all, slow Friday afternoon at work and have been staring at a rock on my desk for the last half hour and have been thinking for cooling down after a boil could I put some stones in the freezer and then drop them into the wort to cool it. The opposite of heating up stones to cook with. I guess there will a chance that the stones may split but I reckon would cool the wort down pretty well. Hmmmm Bring on beer o clock

[6470zzy]

I have heard of boiling with rocks but not cooling, I think that I'll stick to my copper immersion cooler

[OldSpeckledBadger]

It sounds like a great way to introduce an infection.

[dave-o]

Yeah, i'd be worrying about sterility.

[KevP]

Lets hope beer o'clock came quickly and erased that idea from his head!!

[Eric]

The specific heat of beer is about five times that of stone and specific gravity about one third, meaning for equal volumes of stone and beer, the temperature drop of the beer would, I think, be about 30% of their temperature difference.
i.e. with the beer at 80C and an equal volume of stones at -10C, assuming no other heat loss or input, the temperature at equalisation would be 50C such that you would need more stones than beer to have enough cooling. Also conductivity of stone is poorer than either copper or water so the process would likely take longer.
Despite all this, it has appeal considering the amount of work to run cooling water to my boiler.

[Dr. Dextrin]

You working on a Stones Bitter clone then?

[Blackaddler]

I've frozen some treated water into half litre blocks, and added them to the boiler, before now. It didn't really save much time, and letting the heat exchanger do it's job is easier.