A Chinese lidded bowl used for the infusion and drinking of tea and is said to have been invented during the Ming Dynasty when the mode of preparing tea changed from brick to loose leafs. A Gaiwan consists of a bowl, a lid, and a saucer.
Prior to the Ming Dynasty (1368–1644), tea was normally consumed from the vessel in which it was prepared. As described by the tea master Lu Yu, this special bowl had to be large enough to accommodate the implements and actions of tea brewing, though compact enough to be held comfortably in the hands for consumption. The term for this versatile piece of equipment was chawan (tea bowl).
It was during the Ming Dynasty that the innovations in both tea ritual and tea preparation gave rise to the gaiwan.
The gaiwan is particularly suited in the preparation of oolong infusions because of this particular tea's ability to improve by being infused multiple times. The gaiwan is important in tea tasting due to its open and glazed surfaces: the former allows the tea to be viewed while brewing, and the latter prevents altering of the flavour and aroma of the tea during brewing.
A gaiwan consists of a saucer, bowl, and lid. The lid allows the tea to be infused right in the bowl and either be drunk right from the bowl (traditionally using the lid to block the leaves for ease of consumption), or decanted into another container. The gaiwan itself can be made from a variety of materials, including porcelain and glass.
Gaiwans made from Yixing clay or jade are particularly prized by collectors of tea paraphernalia.
Gaiwan is the preferred method for brewing green and white teas as the gaiwan's porcelain absorbs the heat and does not damage the tea. Gaiwans are less suitable for black teas as the large lid allows heat to escape too quickly during the steeping process. They are especially common in the north of China for enjoying scented teas like jasmine tea.