Do you pre-heat the container?
Posted by: guideboatguy on Nov-26-12 12:46 PM (EST)
Perhaps you are comparing them to the old models with the glass insert? The specific heat of steel is quite a bit greater than that of glass, so the need to pre-heat the container is greater. Without pre-heating, a good bit of heat is lost just balancing the temperature of the inside layer of the container with that of the liquid you wish to keep hot. It really makes a huge difference if you pre-heat with boiling water.