A grouphead (or group head) is the receiver for the removable portafilter (or group handle). A typical consumer espresso machine normally has only one grouphead, while popular professional machines, such as those used at commercial coffee shops, can contain anywhere from one to seven. During the process of extracting a shot of espresso, hot water is forced through the grouphead under pressure. The grouphead contains many holes (the shower) that attempt to distribute the pressurised water evenly over the surface of the grinds in the portafilter basket and thereby achieve an even cross sectional flow.
The piston-driven, or lever-driven, machine was developed in Italy in 1945 by Achille Gaggia, founder of espresso machine manufacturer Gaggia. The design generically uses a lever, pumped by the operator, to pressurize hot water and send it through the coffee grinds. The act of producing a shot of espresso is colloquially termed pulling a shot, because these lever-driven espresso machines required pulling a long handle to produce a shot. Lever-driven espresso machines are sometimes called manual espresso machines because of this.
To find espresso machines that perfect the balance between simple design, customizable settings, and delicious espresso, we began by compiling a list of machines recommended by espresso-centric websites like Clive Coffee and Seattle Coffee Gear. We were selective about which brands we chose, skipping the popular Rancilio Silvia Espresso Machine after reading Home-Barista’s lukewarm review of it. We wanted machines that were both well-known and well-regarded. After looking at top sellers from Amazon and Bed Bath & Beyond, we also included the Mr. Coffee Cafe Barista. This addition drew the skepticism of the coffee experts we spoke with, but we couldn’t ignore its 1,700 Amazon reviews.
For many of us, the daily grind can't begin until we've had that first cup of piping hot coffee—so the right brewer is at the top of the list. The most basic coffee makers make at least a decent cup, but a little more money buys conveniences such as programmability, a thermal carafe to keep coffee hot longer, settings that let you adjust brew strength, and more.