Basket
Coffee grounds are held in place during the brewing process by a metallic basket with tiny holes in its bottom from which the liquid escapes the brewing chamber.
Brewing Time
A double shot of espresso will only take 25-30 seconds to fill two 1 oz. cups. If brewed for longer, the espresso will end up with a bitter flavor.
Built-in Grinder
A built-in grinder will crush and tear only the exact required amount of coffee beans to prepare your freshly brewed coffee. Its two revolving disks mill the beans to a consistent ground size. The resulting coffee has maximum freshness and aroma.
Boiler Single/Double
A single boiler heats water for both the brewing and the steaming processes. Because they don’t occur at the same temperature, one has to allow time for the boiler to heat some more between the shot being pulled and the milk being frothed. A double boiler has separate reservoirs, each at the appropriate temperature, enabling simultaneously pulling a shot and frothing milk.
Crema
Depending on the brewing process, crema is a layer of pale to reddish brown foam that forms on top of the well-brewed espresso shot.
Doser
A doser automatically measures and releases the right amount of coffee grounds for a pre-determined shot of espresso: 7-9 grams for a single shot, 14-18 grams for a double shot.
Gasket
The gasket is a rubber ring, especially in the brewing chamber that prevents hot water, steam and coffee grounds from overflowing, and keeps the pressure constant during the brewing process.
Group Head
This chamber is where the coffee grounds are actually brewed. It is pressurized and sealed when the basket is put in place. The espresso comes out through a double-faceted fixture allowing a double shot to be simultaneously poured into two cups.
Long
This term refers to a 2 oz. shot of espresso in the same cup.
Preset
This feature lets a person pre-determine, through a user-friendly interface, the quantity of coffee desired, such as a single or double shot of espresso, a cappuccino or a latte.
Ristretto
As opposed to a long shot, a ristretto designates a short, 1 oz. shot of espresso.
Water Filter
In higher end espresso machines, a mechanical or a charcoal filter is integrated to remove unwanted components from tap water before the brewing takes place.
Water Temperature
The ideal water temperature for brewing espresso is around 92.5 Celsius. If water is too hot, it will burn the coffee grounds; if it is too cold, it won’t be able to extract all the beans’ aroma, resulting in a weak taste.