Gene,
I'll look into that cold block but for a first shot at it I was just
going to coil up some stainless tubing and make two little heat
exchangers, one in hot water at 150F, one in ice water. If it worked
any home winemaker could do it. I was considering just racking through
it, although the pressure differential of a full versus mostly empty
carboy requires consideration. It sounds like a decent experiment
though. I can measure the temperatures of the exchangers, I have the
hardware for that.

Joe