The espresso machine was first invented for commercial use in coffee-houses and cafe-bars. However, as domestic demand grew, manufacturers responded with semi-automatic espresso machines.

Semi-automatic machines gained quick popularity as they were so easy to use. The user still controls the beginning and the end of the brewing process, but the machine develops the water pressure. There are several versions of the semi-automatic espresso machine in which the portafilter makes the difference. Thus,

• The commercial-style portafilter, at 58 mm in diameter, has the same dimensions used on 'presumer machines', a kind of hybrid between home and professional use>. With this portafilter, the quality of the espresso cup depends on coffee-grinding and tamp. You also need to buy a tamper.
• pressurized style portafilter (49mm to 54 mm diameter) itself creates the necessary resistance for the water to pressurize the coffee bed, and is not so dependent on grind size and tamp.

The semi-automatic espresso machine features a heat-exchanger boiler with two thermostats and a switch knob, which allows the operator to control coffee extraction and steaming. Although time is required to switch between the two operations, a good barista possesses enough techniques to reduce the waiting time. The ultimate models also include secondary heating elements inside the boiler which automatically reduce the waiting times.

A characteristic feature of commercial espresso machines is automatic refill, which not available with home-use machines.

The brands

The Capresso Espresso Machine, model 'Pro' has a 40 oz. water reservoir and is one of the best budget choices you can make. Price ranges between $150 and $250. It also features a FrothXpress attachment (32 oz. cold milk container);

Capresso 112SBK Capresso EspressoPro Coffee Center - 112SBK/ Stainless Steel-Lined ThermoBlock Heating/ Two Regular Sieves And One Pod Sieve Included/ 18 Bar Power Pump/ Self-Locking Filter Holder/ 40 Oz. Removable Water Container With Self-Closing Valve/ FrothXpress Attachment/ Separate High-Speed Hot Water Setting/ Striking Art-Nouveau Design

Gaggia Classic Espresso Machine --- The semi automatic model 'Classic' ($500) features the standard 58mm portafilter, temperature stability grouphead, a fast warm-up boiler and rapid recovery times.

Francis Francis Espresso Machine --- featured in several episodes of "Sex And The City" (probably due to its fashionable styling)--- is available at a price perhaps only a movie star can afford: around $800.

FrancisFrancis! X1 Espresso Maker, Red FrancisFrancis! X1 Espresso Maker, Red. The X1 was Italian Architect Lucca Trazzi's first espresso coffee machine. Presented in 1995 and sold in 28 countries, the magazine WIRED described its design as retro-futuristic. Sturdy and easy to use, the X1 also uses Easy Serving Espresso (ESE) pre-ground single servings of coffee sealed in filter paper. The hot water dispenser for tea and the steam nozzle for heating milk for cappuccinos are also very easy to use. All bodies for the X1 in colors are made of metal treated by cataforesis (rustproofing). Includes an instructional DVD, User's Guide, and a complimentary tin of Illy e.s.e. servings. Dimensions: Width 26 cm - Depth 25 cm - Height 33 cm - Water Reservoir 1.5 - Weight 7 Kg Manufacturer No.: 01111

The Rancilio Silvia Espresso Machine is a semi-professional model which made a considerable impact on the web, see the following blog to have a little fun. The Rancilio Coffee Grinder Rocky is its best counterpart. The Rancilio Sivia is priced at around $500.

Rancilio SILVIA Espresso Machine/ Cappucino Maker Stainless Steel "Silvia is a Rancilio's semiprofessional machine. It offer excellent service to your customers and high quality beverages, qualities for which, since 1927, the Rancilio company has been known and appreciated around the world. Iron supporting frame. Body and control panel in satin stainless steel. Equipment: 1 filter holder, 1-cup filter, 2-cup filter, measuring spoon, coffee press."

Saeco Espresso Machine "Classico" model($300) comes with pressurized portafilter, a Saeco patented system, and a 80 oz. water reservoir. This feature means you can brew 40 cappuccinos before refilling.

Saeco Espresso Classico, Black Saeco Espresso Classico, Black. Espresso Classico conbines the original classic all metal body with the Rapid-Steam feature, a remarkable invention that makes life easier. As in commercial technology, it reduces the waiting time between frothing and brewing to zero! There is no need to change the boiler temperature and it completely reduces the handling. Easy and fast to make perfect espresso, cappuccino, and lattes time after time. Featuring a 15-bar pump, a pod adaptable pressurized filter holder for use with ground coffee or pods, a cup warming surface, the exclusive Pannarello milk frothing device and a removable 80 oz. water tank. The Bonus Starter Kit comes with 12 espresso pods, 1 hard cover "Espresso, Cappuccino & Co." book, 2 espresso cups and saucers and instruction video. Everything you need to enjoy your first cup! Please Note: Expedited Shipping and Gift Wrapping are not available on this item. Dimensions: 8 Manufacturer No.: 30054

Solis Espresso Machine - Model 'Crema SL 70' ($375) has one of the biggest boilers in its class.

Solis SL70 Solis Crema SL 70 Semiautomatic Traditional Pump Driven Espresso Machine SL70 Free Shipping! Solis SL70 Free Shipping! Solis Crema SL 70 Semiautomatic Traditional Pump Driven Espresso Machine SL70

Other semi-automatic machines which are less frequently reviewed are: Expobar, Krups, La Pavoni, Isomac, Napresso, Pasquini and Salvatore.