The pump machine has made things much easier for espresso
lovers. Electric steam machines didn't make enough crema,
but electric piston machines could get a little unwieldy.
The pump machine uses a pump that pulls water from
a reservoir and returns it into a tank that heats the
water. Two separate thermostats control brew temperature
and frothing temperature. After the boiler heats the
water to brewing temperature and the brew button is
pressed, the pump activates and water gets pushed through
the boiler, then through the grounds in the brew head.
In order to froth milk, the steam button is pressed
and the unit also heats the water in the boiler, but
to a hotter temperature than brewing temperature. After
steam is produced, a valve can be opened, releasing
some of the steam through the wand.
The first pump machines operated with a boiler. The
boiler, however, can take up to ten minutes to heat
up. The next series of pump machines included a heating
system which could heat the water in a matter of minutes.
Today's pump machines usually take between fifty to
ninety seconds to heat up, and many use super-fast heating
systems called thermal blocks or thermal coils. Others
still use small boilers.
Traditionalists and espresso "purists" prefer
the quality of espresso produced by a boiler machine
than that produced by a thermal coil or block. However,
for the average consumer, the difference in flavor is
nearly undetectable.
Semi-Automatic
The semi-automatic pump machine is one of the most
popular home espresso machines available. It is called
semi-automatic because after flipping a switch, the
pump does the work that the hand used to in the electric
piston machines. The pump will continue pumping water
through to the brew head. Flipping the switch again
will make the pump stop pumping water. (See image 3)
Automatic
The automatic pump machine is very similar to the semi-automatic,
with the following distinction. In the case of the semi-automatic,
a button is pushed once to start the pump for brewing,
once to stop the pump for brewing. In the case of the
automatic, however, a button is pressed to activate
the pump and the machine will stop after a preset amount
of time. (See image 4)
Super Automatic
The super automatic pump machine, perfected by Jura-Capresso
and Saeco, is the same as the automatic except it has
the added feature of grinding the coffee beans (unless
powder is deposited directly into the unit), disposing
of the grounds, and even cleaning, rinsing, and descaling
itself. The super automatics often have many other added
features like strength settings, temperature settings,
digital displays, coffee powder quantity settings, water
amount settings, grind size selections, and others.
(See image 5)
Advantages
--There is much less user error with these push button-based
machines compared to electric piston machines.
--The super automatic pump machines are less messy
than others.
--Proper pressure is always achieved in quality pump
machines, which means simple brewing and usually easy
frothing.
Disadvantages
--Like some owners of manual transmission automobiles,
there are those who prefer the control of electric piston
machines or semi-automatics to automatics or super automatics.
--Most automatics and super automatics have a plastic
hull, which is less sturdy and more easily damaged than
metal machines.
--Super automatic machines are often very pricy, starting
at $450.00 and extending into the several thousands.
