Commercially used espresso machines can be broadly divided into two kinds: semi-automatic and fully automatic. Fully automatic machines are also termed ‘super-automatic espresso machines’. These machines are fast gaining entry into the commercial as well as the household use.
In a semi-automatic espresso machine, the amount of water used for making coffee can be determined by either the user or the machine. Also, the user has to dispose and dose the coffee grounds. The user also steams the milk using a steam wand.
An automatic espresso machine may offer automatic brewing, in which the machine defines the amount of water to be used. These machines typically have two settings, single and double shot.
Various automatic machines also offer automatic dosing, in which the machine takes in the proper amount of coffee, and discards it after brewing. Coffee is ground, dosed, brewed and discarded automatically in a maker which offers automatic grinding. The bypass doser feature in some machines allows one to use ground coffee and adjustable dosage.
Semi-automatic espresso machines are those used at homes or a small scale office or restaurant. A heat exchanger or distributor is used to heat the brewing water. This is one of the most important differences between automatic espresso machines and good home espresso making machines. The boiler is used for the steam, and is kept at a higher temperature. This also ensures that the steam is available at all times.
While single boiler machines use only one boiler for preparing steam and heating the brewing water, the heat exchanger or extra boiler makes it unnecessary to switch modes while using automatic espresso machines.
After the coffee is brewed, the pressure in the portafilter is automatically released through a valve.
Some companies manufacturing semi and fully automatic espresso making machines are Gensaco, Krups, Pasquini, Brasilia, and Europa.