How to Choose a Tea Cup: Porcelain, Bone China, Double-Walled Glass, Clay and Steel

Porcelain has been the material of choice for tea for centuries. Made from very fine kaolin, or china clay, and fired close to its melting point, it comes out thin, smooth, almost translucent and essentially non-porous, and its glaze does not react with tea.

Firing is what separates the clays. Our 2016 teacup essay gives earthenware as fired at 950 to 1,100°C and stoneware at 1,160 to 1,300°C, while porcelain is “typically fired at 2,300 degrees” Fahrenheit, around 1,260°C. Porcelain is hard to work because its clay lacks the plasticity of the others, and it “cracks and deforms easily in firing since the ideal density is achieved very close to the melting point.” The reward is a cup that is “thin, almost translucent, delicate and smooth.”

Bone china

Bone china adds bone ash to the clay and became the dominant material in English teaware; our essay credits its invention to Spode. Spode worked in Stoke-on-Trent, “a historic center of English ceramic production where the likes of Wedgwood, Spode, and Minton established their factories in the late eighteenth century,” as the art historian Romita Ray wrote for us.

Shape and the tasters’ choice

A porcelain tea cup feels fine on the lip and suits every tea, and porcelain is still what professional tasters use. Traditional porcelain cups are narrow at the base and widen toward the top, a shape that balances keeping the tea warm with opening up its aroma.

Our own porcelain has included the Heritage Holiday Tea Set of 2015, “handcrafted in porcelain,” with a teapot with a copper handle and four teacups, and the Jubilee Set of 2016, “a five-piece bone china tea set for two.” Our Heritage cup held 150 ml, the size a teapot “cup” is reckoned by.

Glass is non-porous, very smooth and easy to clean, and borosilicate glass, which adds boric oxide to the usual ingredients, is tough and handles heat well. Its real pleasure is that you can see the tea: “the transparency of the glass shows both the color of the liquor and the unfolding of the leaf.” Peter Keen, writing for us, noted that it is “generally the same borosilicate that laboratory test tubes are made of,” and free of any plastic or metal taste.

How the double wall works

A double-walled tea cup is a cup within a cup, separated by a layer of air: the inner wall keeps the tea hot while the outer one stays cool to the touch. As we said when we first sold them: “No condensation. No coasters needed!” Of our Cyril cup and saucer we wrote that “being double-walled in design, it keeps the liquor hot for a long time and doesn’t burn your fingers too.”

Our Valencia Glass Teacup is double-walled borosilicate and works for hot and iced tea alike. Our spec sheet rates it from 0°C to 100°C.

Sizes we have sold

Glass cups come small. Our Duple Glass Teacup held 200 ml and our clear borosilicate Bolus Cup and Saucer 250 ml, while the Seidel infuser mug holds 300 ml. Measure your favorite cup before you weigh the leaf: about 2 to 2.5 g suits 250 ml, so a 200 ml cup wants a little less.

Treat a double-walled cup gently: its two thin walls are sealed around the air gap, so set it down softly and keep it clear of knocks against taps and counter edges. It also will not warm on a tea warmer, because the same air gap keeps the warmer’s heat out; see Teapots, infusers and tea makers.

The biggest difference between porcelain and glass is not heat but the lip. Our tea essay summed it up as “SS for porcelain, Sit and Sip, and GG for glass, Glug and Go.” A thin porcelain rim lets the tea glide onto your tongue and invites you to slow down; a thick rim makes you take a bigger gulp, which is fine for a bold breakfast tea but hides the detail in a delicate one. The suggestion: a porcelain cup at home, and a double-walled glass with a built-in infuser for the office or travel.

The essay explains why: “The thinner the lip, the more you naturally let the tea glide onto your tongue,” while “the thick material of glass and stoneware retains the heat well, but it creates an autonomic reflex to take a big gulp of the tea.” Try it with the same Darjeeling in two cups and you will taste the difference.

And the saucer?

The saucer once had a job of its own. Peter Keen’s samovar story shows an 1860s St. Petersburg photograph by William Carrick of two carriers in a tea room; one is drinking from his saucer, “a habit among some of the working class in England and Ireland and prevalent in Russia for an obvious reason: cooling the hot tea quickly.”

Our writer Anik Basu found the habit in an unexpected place: Rabindranath Tagore poured his tea into his saucer at a tea in Japan in 1916 to 1917, though Anik doubts there is any Indian tradition of saucering.

Clay covers a wide range. Earthenware is fired at lower temperatures and, unglazed, stays porous. Stoneware is fired hotter, is dense and heavy, holds heat well and makes most everyday mugs; its thick lip makes it a natural “Glug and Go” cup for strong milky tea. Our essay adds that because stoneware holds heat so well, it can crack under a sudden change of temperature, so do not pour boiling water into a cold stoneware mug straight from the fridge.

The kulhad

In India, clay means the kulhad, the small clay cup of the chai stall, also called a khullar or, in Kolkata, a matir bhaar. It belongs to chai culture rather than to fine-tea tasting. Kolkata, our founder wrote, is known for “its love for tea, matir bhaar & adda.”

The street kulhad is unglazed and used once. Our own kulhads were different: the Indus Kulhad (200 ml) and the Terra Mug (300 ml) were “handmade earthenware… hand-glazed & wood-fired ceramic,” made especially for us by master potters, a long-lasting version of what were “originally disposable mud pots.” Being handmade, each one had “some patches and spots on it and dissimilar finishes.” The glaze is what matters for taste: a glazed kulhad behaves like any glazed cup, while an unglazed one takes on the flavor of whatever it holds.

A potter in Kutch

For a gentle story of a clay cup of tea, read Pottering with Clay, about the Kutch master potter Ismail Siddiq. When Aditi De met him in February 1981, the National Award-winning potter, then 72, handed her “a warm khullar, a little clay cup of tea” while he fixed a handle to a cup with clay slip. “I am the only potter for a cluster of 20 villages near Bhuj in Kutch,” he told her. “Four times a year, the farmers come and take my pots… In return, they give me grain or goats.”

Stainless steel tumblers are common in India and nearly unbreakable, but steel carries heat to your lips quickly, so the rim can feel too hot to sip. Plastic is light and cheap, but tea connoisseurs do not recommend it for hot drinks.

Steel is a different matter for brewing tools. A steel teapot “impresses tea with a metallic taste,” Adeline Teoh found, but a steel infuser spends only a few minutes in the cup and comes out clean. That is why our infusers and the Ideal Teaspoon are stainless steel.

The greener choice

There is a greener reason to choose well, too. We have long encouraged “100% borosilicate glass teapots, makers and cups, stainless steel infusers, and earthenware accessories in place of inferior quality material like plastic,” and loose leaf instead of teabags.

On Earth Day 2021 we pledged to cut our own plastic use by 80% by 2024, and asked tea drinkers to “use eco-friendly teawares such as borosilicate & stainless steel.” By November 2021 everything we shipped except teaware was wrapped in honeycomb paper instead of bubble wrap, and on Earth Day 2024 we reported that the pledge had been met.