This type of espresso maker gives the user control over the extraction process by allowing them to manually start and stop the flow of hot water through the portafilter. This differs from fully automatic machines, which automate the entire brewing cycle, and manual lever machines, which require the user to manually generate the pressure. A typical example involves the user grinding coffee beans, tamping the grounds into the portafilter, locking it into the group head, and then activating a switch to initiate the brewing process. Once the desired amount of espresso has been extracted, the user deactivates the switch.
The ability to control the extraction time provides flexibility and allows for experimentation with different brewing parameters to achieve the desired flavor profile. This level of control is prized by coffee enthusiasts who appreciate the nuanced flavors that can be achieved through precise adjustments. Historically, these machines bridged the gap between fully manual lever machines and fully automatic options, offering a balance between ease of use and control over the brewing process. They became popular with home baristas seeking a more hands-on approach to espresso making without the complexity of a fully manual machine.
