Originally Posted By: tanstaafl.
Originally Posted By: TigerJimmy
It probably evaporates out the top.
Uhhhh... no. I blocked the top and the water level still dropped.

A bit more research shows that the water does indeed migrate through the porous terracotta clay of the carafe where it evaporates, cooling the outer surface of the pot which in turn allows heat to flow by conduction from the inside of the carafe.

tanstaafl.


Yeah, ceramic is porous of course, but I would have thought the glaze was not.