Espresso Coffee Maker
An espresso coffee maker is used to produce the
traditionally Italian coffee beverage called espresso. The skill
required in making the finest espresso is considered to be a craft.
The act of preparing a shot of espresso is also termed ‘pulling a
shot’, because old lever-style espresso machines required pulling a
long handle to produce a shot. To pull a shot of espresso, a metal
filter-basket is filled with either 7-10 grams or 12-18 grams of
ground coffee for a single shot (30mL) or double shot (60mL),
respectively. When the brew process begins, pressurized water at
around 90°C is forced into the group head and through the ground
coffee in the port-a-filter. High-quality espresso machines control
the temperature of the brew water within a few degrees of the
ideal.
This process produces a rich, almost syrupy
beverage by extracting and emulsifying the oils in the ground
coffee. An ideal double shot of espresso should take 25-30 seconds
to arrive, timed from when the machine's pump is first turned on.
Varying the fineness of the grind, the amount of pressure used to
tamp the grinds, or the pump pressure itself can be used to bring
the extraction time into this ideal zone.
Various types of espresso coffee makers can
be:
Semi-automatic espresso coffee maker: Although
semi automatics have an electric pump that produces the appropriate
pressure for brewing, they still require quite a bit of user
control. This is especially true if you’ll be brewing with ground
coffee, but some models also offer the option of brewing with
prepackaged espresso pods. These machines are available in 2
styles: semi-automatic, with which you start and stop the brewing
process manually, and fully automatic, which have brewing buttons
that can be programmed to yield a specific amount of espresso.
Automatic espresso coffee makers: Automatic
espresso machines are similar to semi-automatic except that they
have a flow meter installed inline with the group-head. When the
programmed amount of water has flowed through the flow meter, the
pump is automatically turned off and brew pressure released through
a three way solenoid valve.
Super Automatic espresso coffee maker: Super
automatic machines do it all and do it with style. You need to
press just one button and a super automatic grinds whole beans
inside the machine, tamps down the grounds, brews a delectable
shot, and holds the waste in an internal container for later
disposal. Basically, these machines operate by automatically
grinding the coffee, tamping it, and extracting in much the same
way an automatic espresso machine does. The difference is they are
fully self-contained; all you do is fill the bean hopper and water
reservoir. (Some machines are now fully plumbed, so water is drawn
into the machine, eliminating the need for a water reservoir.)
After brewing, the machine will automatically
dispose of the spent puck. The process of making the espresso is
done by a brewer. Many of these machines have coffee dosing, water
flow, and shot-temperature adjustability. Additionally, many models
now feature automated milk-frothing devices. These models are
becoming increasingly popular for home use. There are quite a range
of super automatics available, but they will all complete the
processes mentioned above – the differences come down to the
programmable features and other options each machine has.
Manual espresso coffee maker machines: Manual
espresso machines require more user control than those mentioned
above. Pressing the lever on a manual machine creates the necessary
pressure for brewing and forces hot water through your
port-a-filter full of grounds. With a manual machine, you have
maximum control over the final product.
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