grandpa
老人茶
"Grandpa style" is the casual everyday method common in working-class
China — leaves loose in a glass or thermos, hot water topped up
repeatedly throughout the day. The leaves sink (or float and then sink)
and the cup is sipped slowly, more water added when low. Best with
teas whose leaves resist over-extraction (greens with pulled leaf,
most cooked pu-erh, robust oolongs).