Double-walled glasses

Start with the capacity, because that is where it usually goes wrong. An espresso is 25 to 30 millilitres and looks lost in a large glass, so reach for 6.5 or 8.5 cl instead. A cappuccino sits well at 11 to 15 cl, a regular coffee or a cup of tea at 22 to 30 cl. A latte macchiato with three visibly separated layers needs at least 34 cl, otherwise the milk and the coffee run into each other. The 38 to 40 cl sizes are meant for iced coffee, iced tea and long drinks.

The second question almost everyone asks is about handles. This range includes a 32 cl mug with a handle, but most models do without one, and that is a deliberate choice: the outer wall simply never gets hot enough to need one. If you do want something to hold on to, look at the mug or at an espresso glass that sits on a stainless steel saucer. Finally, pay attention to the wall thickness. Borosilicate glass is thin and remarkably light, and it is precisely that thin wall that makes the floating effect so striking.

Pour hot drinks slowly and keep the stream in the middle rather than against the wall. A double-walled glass copes perfectly well with boiling water, but a concentrated hot stream on a single spot is never wise with thin glass. For tea, fill to a centimetre or two below the rim, so you can still pick the glass up without spilling.

The coffee itself deserves your attention. Pull an espresso straight after grinding, because in a small glass you smell the crema far more strongly than from a thick cup. Build a latte macchiato by pouring in the foamed milk first and then letting the espresso sink slowly through it; the difference in density does the rest. And because these glasses insulate cold drinks just as well, an irish coffee or an espresso tonic works in them too, without the ice melting away immediately.

Borosilicate glass owes its heat resistance to the boron trioxide in the mix: it barely expands when temperatures change, so a crack caused by a sudden switch from cold to hot is rare. Strong in the sense of tempered catering glass, however, it is not. The walls are thin, and a knock against the tap or a spoon dropped into the sink is enough.

They are dishwasher safe on a short glassware cycle, as long as they are not touching each other. If you see moisture between the two walls after washing, water has got in through the small vent hole in the base. Stand the glass upside down somewhere warm and let it dry for a day; it will disappear by itself. Limescale streaks polish away with a lint-free cloth.

If you are looking for single-walled glassware for the same drinks, you are one click away. The coffee glasses form the broad category this page belongs to, and within it the latte macchiato glasses and the cappuccino glasses are sorted separately by size. If you mostly drink tea, take a look at the tea glasses, which include models with a handle. For cleaning narrow, tall glasses the glass brushes are handier than a washing-up brush, because an ordinary brush will not properly reach the bottom of a 40 cl glass.