I just tried a small Xiao tuocha bowl from my local tea shoppe. As it came apart it released little bubbles of trapped air almost like a tiny fountain of champagne. I'd guess 50% volume was trapped air. There was a beautiful red plume of color like a volcanic eruption as the tuocha broke apart. I had to swirl the pot to complete the infusion. The pot was so red it was almost black. It so dropped the water level I thought I had a leak but comparatively little leaf in the pot. Mine tasted like the shoeleather fishy version. I'm about ready to do some holiday shopping in Chinatown. Hopefully the cakes will be as plentiful as our fruity kind.
Jim