This collection of illustrated
definitions will clarify the specific functions of
espresso machine parts and enhance your barista
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. Espresso machines usually
come with a single-shot and a double-shot
A double shot of espresso will only take 25-30 seconds to fill
two 1 oz. cups. If one brews for a longer period, a bitter
flavor will end up in the espresso.
espresso machine between each shot is important in order
to keep it running smoothly. Using a brush to clean the
group head and the steam wand will ensure the best flavor
in your cup.
A built-in grinder will crush and tear only the required amount
of coffee beans to prepare the immediately desired brewed
coffee. It consists of two revolving disks milling the beans to
a consistent ground size. Resulting coffee has maximum
freshness and aroma.
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.
Depending on the
brewing process, crema is a layer of pale to reddish
brown foam that forms on top of the well-brewed espresso
Available in the form of powder, pods or descaling solutions,
this chemical product should be used every 6 months to remove
mineral deposits such as lime scale from the tank, boiler and
pipes of the espresso machine.
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.
This sensor automatically sends a signal that interrupts the
water flow when the preset amount of coffee has been
Especially in the
brewing chamber, the gasket is a rubber ring that
prevents hot water, steam and coffee grounds from
overflowing, and keeps the pressure constant during the
This chamber is where the coffee grounds are actually being
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
a Water Line
A typical espresso
machine requires the user to manually fill a water tank
as the first step of preparing an espresso. However, with
a higher-end model, it is possible to directly hook it
onto a water line, thus eliminating the need to fill the
reservoir and the risk of burning the element in case the
machine runs out of water.
This term refers to a
2 oz. shot of espresso in the same cup.
Also called a steam wand, this pipe usually found on the side
of the espresso machine is used to alter milk by raising its
temperature and introducing tiny air bubbles, thus creating a
thick, foamy froth to top a cappuccino or a latte.
A handle on
one end and a cupped shape on the other, it holds the
basket in place during the brewing process and allows
easy manipulation for sealing the brewing chamber as well
as littering used coffee grounds.
Brewing espresso relies on two important factors: hot water and
pressure. Energy must be converted to heat water and build that
pressure, and the source of this energy is called the power
source. It can be electrical or external, such as gas or wood,
depending on the type of espresso maker.
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.
device mechanically builds the pressure (8-10 bars)
required to force hot water through coffee grounds,
instead of depending on steam pressure which might result
in brewing at a higher than ideal temperature.
Opposed to a
long shot, a ristretto designates a short, one ounce shot
This is the process through which
coffee grounds are compressed within the basket prior to
brewing. The tamper is the tool used for tamping, and typically
requires 30 pounds of pressure for the perfect
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. If one uses natural
spring water to prepare espresso, the natural minerals in it
might actually contribute to the espresso’s flavor, eliminating
the need for a filter.
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.