Using a Gaiwan

Because of its simple shape with a wide opening and no undercuts in the interior, the gaiwan is easy to clean and slick to use, once you get used to it. When it holds a small amount of leaves as in conventional tea making approaches, the wide, inverted bell shape facilitates convection of the water inside for optimal infusion effects. Better yet, its openness enables it to hold large amount of leaves, even bulky ones, easily so that those prefer the gongfu approach have it as a staple tool.

Choosing a Gaiwan: Sizes and Shapes

There are quite a range of sizes and shapes. My recommendation is based on functionality and versatility. Disregard my opinion if you want to buy them for fun or collection purposes.

The ergonomics and heat physics of the shape is considered for how the ware can be used both as an effective tea infusion tool as well as a cup to drink from. In addition to the choice of material, there are five main considerations:

Height-Width Ratio

The ratio determines how easy it is for the lid to turn the ball of tealeaves gathered towards the bottom of the gaiwan. The height of the bowl itself should be at most two-thirds of the diameter of the lid when one intends to use it in gongfu tea-making.
Bowl Shape

The tapering of the bowl should be such that the ball of tealeaves can be easily gathered at the bottom for turning and cleaning. The bottom can be angled or round. The tapering also facilitates flow of liquid during decanting or drinking.

Lid Shape

The button of the lid should concave in the centre such that it can be an effective heat dissipater rather than a heat reservoir, or you burn your finger. The dome of the lid should be slight, but not flat, such that enough air is trapped between the liquid and the lid as an insulation layer. Over doming makes it difficult to handle when you need to press the lid down during decanting.
gaiwans with colour overglazes

140 ml gaiwans, porcelain with colour overglazes. This is the standard, and well-proven, shape of gaiwan for gongfu tea-making. Great as a cup as well.

Saucer Shape

The saucer doubles as the handle when the ware is used as a cup. Therefore, the bowl has to be able to sit comfortably and securely in it so that when the hand lifts the saucer there is little rattling of the bowl inside the saucer. Such that it feels safe when the hand tilt the saucer to tilt the bowl for drinking. Therefore, the depth and shape of the concave in the centre is critical. The width of the ring determines how easy it is to lift the bowl by holding it. Too small, the bowl becomes heavy and clumsy to handle; too wide, the saucer hits the chin.

The size of the user’s hand and how comfortable she is able to control the ware is another major consideration. Your confidence of the tool determines the quality of your infusion, as in cooking.

Material thickness
Tall gaiwan with blue glaze

Tall gaiwan with blue glaze. A tall shape is best for use as a cup and for infusing green or black teas employing longer infusion time. This particular design has a ring saucer, an homage to the structure when it was invented, probably in the 9th century

The size is considered together with heat dissipation quality for the ware’s optimum infusion capability. For mould-made gaiwans, which I use normally for economics, I usually go for those with an average thickness of 1.5 mm (side walls of the bowl) and capacity of 140 ml. That is good because the infusion duration I use with these gaiwans is usually between 20 seconds to 3 minutes.

If you use longer infusion time, use a larger, or a thicker one.

I have not done any scientific calculations and recorded experiments with it, but when the thickness goes up to around 2 to 2.5 mm, the heat holds a lot longer. However, the material becomes a bit too hot to handle with ease, and pouring becomes much more clumsy.