Tempering: Pre-Warming Tea Mugs / Cups / Gaiwans?

I would think that it’s all the more important to temper the materials with low temperature resistance to avoid heat shock (glass especially), but alot of the newer ones made with borosilicate can hold up better to sudden heat than older lime glass models.

Tempering depends on my mood, brewing vessel, and tea. I usually don’t temper thermoses, but I’ll do sometimes for ceramic and glass. Sometimes the tempering is just the beginning of a relaxing tea time.