Porcelain
The default material for tea vessels almost everywhere, and the one that changed European drinking habits. Porcelain is vitrified, meaning the body has been fired until it is effectively glass throughout, so it absorbs nothing and gives nothing back. That neutrality is why it is the material a tea is judged in.
What it is
A ceramic fired at roughly 1300 to 1400 degrees Celsius from kaolin clay plus a feldspathic rock the English called petuntse. The result is hard, white, thin enough to be translucent, and resonant when tapped. Stoneware is fired lower, between about 1000 and 1300, and is not always vitrified, so it usually needs a glaze to be watertight. Bone china adds bone ash, which makes it stronger and more translucent still.
What it does to your tea
As close to nothing as any material gets, which is its entire value. A vitrified body has no open pores, so it holds no oils and carries no aroma from the last tea. It also insulates well: ceramics conduct heat roughly a hundred times less readily than metals, and the small air pockets in an ordinary mug body act a little like a padded jacket. A thin porcelain pot cooled by 7 degrees over a four-minute infusion in Francl's measurements, comfortably better than cast iron.
What it suits
Everything, and delicate teas in particular, where anything the vessel contributes is a loss. It is the correct material for comparing two teas, because it is the one that does not have an opinion.
Care and cleaning
Anything. Detergent, dishwasher, scouring within reason. Tannin staining is cosmetic and lifts with bicarbonate of soda. The real weakness is brittleness: porcelain is polycrystalline, so stress has no plane to travel along and the body simply snaps rather than deforming.
What people get wrong
Assuming translucency means fragility in use. A thin porcelain cup is more resistant to thermal shock than most thick earthenware, which is precisely why porcelain took over European tea drinking in the first place: British earthenware crazed and cracked under hot liquid and Chinese porcelain did not. Thomas Tickell was writing poems about it in 1722. The story is usually told as tea creating demand for porcelain, and the ledgers suggest it also ran the other way, with a taste for porcelain encouraging something worth drinking out of it.
Made of this
Sources
- porcelain is fired at roughly 1300 to 1400 °C from kaolin and petuntse, giving a vitreous body resistant to stain and thermal stress; Jingdezhen produced over 3 million pieces a year by the early eighteenth century Ellis, M., Coulton, R. & Mauger, M. (2018). Empire of Tea: The Asian Leaf That Conquered the World. Reaktion Books
- 500 g of water at 100 °C fell to 80 then 76 °C in a 1200 g cast iron pot and to 90 then 82 °C in a 400 g glass pot; a double-walled glass pot held 93 then 89 °C Francl, M. (2024). Steeped: The Chemistry of Tea, chapter 7. Royal Society of Chemistry