Anybody looking for a coffee machine for home use will no doubt have been overwhelmed by the large number of coffee makers available to buy. There are many types of coffee makers available from pump coffee machines, automatic coffee makers, bean to cup coffee makers and now even hand held coffee machines.
The best 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 honest about how in depth and technical you wish your home use coffee maker to be, some coffee makers can be a pain to fathom!
It is also necessary to know your budget, the cost of the various coffee machines varies significantly from the small hand held coffee machines - which make great gifts - to the impressive £2000 plus fully automatic espresso makers offered by the likes of Gaggia espresso machines which are suitable for use in busy coffee shops, an unlikely gift even from the most generous.
It is a good idea to look at the reviews and try to understand the functionality of the coffee maker prior to buying one. Here are a few hints, tips and nods towards certain coffee machines.
Steam-driven coffee machines operate by pushing water through the coffee grinds using steam or steam pressure. The first coffee machines were steam types, produced when a common boiler was connected to four group heads so that many types of coffee could be made at the same time. The design is still used today in low-cost consumer coffee machines, as it does not need to contain moving parts. Many cheap steam-driven units are sold in combination with a drip-coffee machine.
Piston-driven coffee machines or lever driven machines 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 send it through the coffee. The act of producing a shot of espresso is colloquially termed pulling a shot, because these lever-style espresso makers 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 user directly pushes the hot water through the grounds. In the spring piston design, the user tensions a spring, which then delivers the pressure for the espresso (usually 8 to 10 bar).
Pump-driven espresso machines are a refinement of the piston coffee maker, which is the most popular make in professional espresso bars. Instead of using manual force, a motor-driven pump provides the force necessary for making espresso. DeLonghi coffee machines are themost popular manufacturers for this type of coffee machine.
Commercial coffee machines or some high spec domestic coffee machines are often attached directly to the water supply on the site; lower spec home coffee machines have built-in water reservoirs.
Some home pump espresso machines typically use a single chamber both for boiling water to brewing temperature, and to heat water for steamed milk. Since the temperature for making espresso is normally less than the temperature for creating steam, the machine requires 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 domestic use, water for brewing is heated in a separate chamber.
Coffee machines which also feature sensors, valves, pumps, and grinders to automate the brewing process generally are called automatic.
Semi-automatic coffee machines are automatic in the sense water is delivered by a pump, opposed to manual force and the remaining pressure in the basket is used up with a three way valve.
Automatic coffee machines add a flowmeter inline with the grouphead. When the pre determined amount of water has flowed through the flowmeter, the pump is automatically switched off and brew pressure dispersed through a three way solenoid valve.
Super-automatic machines operate by automatically grinding the coffee beans, tamping it, and extracting; all an operator needs to do is fill the beans, and if the coffee maker is not plumbed in a water line, add water to a reservoir. Additionally, models contain an automated milk frothing and dispensing device.
Recently air-pressure driven portable coffee makers have come onto the market. A Handpresso is a portable coffee machine . It works by pumping air at very high pressure (16 bar) into an intermediate chamber. Boiling 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 coffee maker is now turned upside down and the pressure from the storage chamber is released into the water container. The high pressure pushes the water through the coffee pod and into a cup, which should be put under the coffee maker. When the required amount of espresso is brewed, the pressure is released from the water container and the infusion process ends.