Anybody searching for a coffee maker will probably have been overwhelmed by the large number of coffee makers available to buy. There are many types of coffee makers available from piston coffee machines, fully automatic coffee makers, bean to cup coffee makers and now even portable coffee machines.
The easiest method for deciding on the correct coffee machine for you is to look at your lifestyle, the type of coffee you like to drink and be truthful about how in depth and technical you wish your coffee machine to be, some home use coffee makers can be a pain to fathom!
It is also necessary to understand your budget, the cost of the various coffee makers varies significantly from the small portable coffee machines - which make great gifts - to the impressive £1500 plus fully automatic espresso makers offered by the likes of Jura coffee machines which are suitable for use in busy coffee houses, an unlikely present even from the most flamboyant.
It is a good idea to read the reviews and try to understand the functionality of the machine prior to purchasing. Here follows a few pointers towards certain coffee makers.
Steam-driven coffee makers operate by forcing water through the coffee using steam or steam pressure. The first espresso machines were steam types, produced when a boiler was piped to four group heads so that multiple types of coffee could be made at the same time. The design is still used today in the cheapest consumer machines, as it does not need to contain moving parts. Many cheap steam-driven machines are offered in combination with a drip-coffee machine.
Piston-driven coffee machines or lever coffee makers were first made in Italy in 1945 by Achille Gaggia, founder of Gaggia espresso machines. The design normally uses a lever, pumped by the operator, to pressurize hot water and pass it through the coffee. The act of producing a shot of espresso is colloquially termed pulling a shot, because these lever-style espresso machines required pulling a long handle to produce a shot
There are two types of lever machines; manual piston and spring piston. With the manual piston, the operator directly pushes the water through the ground coffee. In the spring piston design, the operator works to tension a spring, which then delivers the pressure for the coffee (usually 8 to 10 bar).
Pump-driven coffee machines are a refinement of the piston machine, which has become the most popular design in professional espresso bars. Instead of using manual force, a motor-driven pump makes the force needed for making espresso. DeLonghi coffee machines are themarket leaders for this type of espresso machine.
Commercial coffee machines or some high-end home use coffee machines are often attached directly to the water supply on the site; lower spec home coffee machines have built-in water reservoirs.
Many home pump espresso makers typically use a single chamber both for boiling water to brewing temperature, and to boil water for steamed milk. Since the temperature for brewing espresso is normally less than the temperature for making steam, the machine needs time to make the transition from one mode to the other. Water for brewing can pass through a heat exchanger (taking some heat from the steam, without rising to the same temperature). In some coffee machines, for commercial or home use, water for brewing is heated in a separate chamber.
Espresso machines which also feature sensors, valves, pumps, and grinders to automate the brewing process generally are referred to as automatic.
Semi-automatic coffee machines are automatic as water is delivered by a pump, opposed to manual force and the remaining pressure in the basket is dissipated with a three way valve.
Automatic coffee makers add a flowmeter inline with the grouphead. When the pre-programmed amount of water has flowed through the flowmeter, the pump is automatically switched off and brew pressure let out through a three way solenoid valve.
Super-automatic machines operate by automatically grinding the coffee, tamping it, and extracting; all any user need do is fill up the beans, and if the machine is not plumbed in a water line, add water to a reservoir. Additionally, super automatic models contain an automated milk frothing and dispensing device.
Recently air-pressure driven portable espresso machines have come onto the market. A Handpresso is a hand held coffee machine. It works by pumping air at very high pressure (16 bar) into an intermediate chamber. Hot water is then put into a small reservoir, which can contain hot water for one cup of espresso coffee. Ground coffee is inserted on top of the water reservoir and a portafilter is attached on the top of the water reservoir. The machine is now turned around and the pressure from the intermediate chamber is released into the water container. The high pressure forces the water through the coffee pod and into the cup, which should be put under the machine. When the required amount of espresso is brewed, the pressure is released from the water container and the infusion process stops.