There are some pretty impressive gourmet restaurants out there. At times, the food may be debatable, but the presentation is always impeccable. Great chefs know that a part of the culinary experience lies in the table service. You just don't serve a gourmet meal on disposable plates. And, so it is with fine espresso. But, it's not solely aesthetics; the cup you're extracting into could have a tangible impact on your espresso.
Everything from the shape, size and material of a cup should be taken into account. Though there is no "standard" shape for an espresso cup, most of them tend have to a softly rounded form that is narrow at the bottom and gets progressively wider at the rim. The wider opening at the top is said to enhance crema presentation, while narrow bottom encourages espresso flavor concentration. The shape also allows to the cup to retain heat evenly so that you don't get hot and cold spots within your beverage.
The size of the cup is also critical. A widely respected espresso authority, the World Barista Championship (WBC), states in its Rules and Regulations that espresso must be served in two- to three-ounce (60-90ml) cups with handles. The Gaggia Logo, Rancilio Logo, Pasquini Logo, Illy Almodovar and Julian Schnabel espresso cups are all solid choices that fall within WBC guidelines. Espresso cups are made tiny for a reason. The compact size of the espresso cup is designed to promote heat retention by reducing the surface area exposed to the air. Also, a single shot of espresso is only 1-1.5 fl.oz, while a double shot barely tips the scale at 2-2.5 fl.oz, so the espresso would be lost in a large cup. A 2-ounce cup is perfect for a single shot; if you're brewing a double go for a 3-ounce demitasse.
Espresso-machine manufacturers go through great lengths to ensure heat stability during the brewing process, but once the espresso is extracted, it's up to the cup to prevent heat loss. We always advocate preheating your cups, but you can also guard against premature cooling by paying close attention to the material of your espresso cup. Most demitasses are made of porcelain, as it is an excellent insulator. Though, you should keep in mind that there are different grades of porcelain. Porcelain created using high firing temps is tougher and more durable; most connoisseurs prefer thick porcelain espresso cups like the Bodum Pavina Grip Porcelain, and Gaggia Platinum cups. Also particularly adept at heat preservation are double-walled cups. The contents stay hot while the exterior of the cups remain cool to the touch; if this is appealing to you, check out the Bodum Pavina, Assam or Canteen Glass cups. Of course, glass cups also have the added advantage of allowing you to see and appreciate your espresso.
Next time you're pulling a shot, take a moment to consider the cup! Good espresso deserves to be enjoyed from great cups.