How Does Machine Espresso Work?

The machine espresso makes use of precise pressure, as well as a filter technology that is mind-blowing to make the coffee you enjoy. How exactly does it work?

To make espresso, hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee. However it is the pressure that makes the main difference.

The Group Head

As the name suggests, the group head is where you place your portafilter while brewing espresso. It is responsible for dispersing water into the portafilter before controlling the pressure that results from the extraction. There are many different types of group heads, each with its own advantages and drawbacks. Some are designed to provide the stability of temperature while some are designed to handle pre-infusion. Others are made to control the lever. Some come with a combination of both, like the E61. This is a preferred choice for baristas due to the fact that it has multiple benefits in a single package.

As you can see in the above photo the group head comes with many notches in which you can put your portafilter, then twist it with your hands to lock it in. There is also a gasket made from rubber that is a part of the notches and helps create the seal when you insert your portafilter into the machine. The notches on the head allow for an exact location of the portafilter which is necessary to ensure an efficient extraction.

In addition to allowing you easily connect your portafilter, the group head is also responsible for maintaining an even temperature. This is achieved by cycling hot water around the portafilter, and through the brew-basket, making sure that the temperature is at the right level to extract the coffee. This is vital, because just a few degrees could mean the difference between excellent and great espresso.

The Pump

In contrast to manual piston machines that use a lever to pressurize water, the rotary espresso machines use motorized pumps to deliver the nine atmospheric bars of pressure necessary to extract espresso. This pressure is generated by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are typically cheaper and last longer than piston-driven machines. However, both types of machines can degrade because of frequent use and poor cleaning. They also increase the complexity of mechanical systems, which can result in a high price tag on even the most basic models.

Some espresso machines remove the pump entirely and utilize steam pressure to make espresso. This can lead to over-extraction as the boiler that produces steam also warms the water to boil. In addition these machines typically have to rebuild their pressure between cups, which requires time and energy.

Many espresso machines use an rotary or a vibration pump. A vibration model employs the vibrating disk to create pressure, whereas the rotary model pushes hot water through the ground at a high speed. Both machines produce great espresso however rotary machines tend to be quieter, more durable and less likely to break.

The Boiler

The boiler is the part that heats water best ground coffee for espresso machine bean to cup espresso machine small machine (research by the staff of Werite) the optimal temperature to extract. The steam that is created gets to the portafilter which is a container for espresso grounds. It is then funneled into the cup. During this process the steam is able to create enough pressure to push the grounds of coffee through. This creates a foam on top of the espresso. This is a sign of a great espresso.

There are three types of espresso makers. They differ in the type of pump they employ and the degree of heat that the brew is. There are different ways that the brew may be controlled and the size of the cup the machine can produce.

The first espresso machines were steam type. They employed one boiler to make both steam and brew however, the pressure they could produce was not very high - two bars of atmospheric pressure, at most. This resulted in the coffee tasting bitter and burnt. This is the reason why Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni developed the modern espresso machine.

The most common espresso maker is a semiautomatic machine with an electric pump. When people think of espresso machines, they picture these machines. Semi-automatic machines require you to grind and tamp the beans yourself, but the pump regulates the flow of water and pressure. This is a great compromise between human control and mechanized reliability.

The Filter

Typically, espresso capsule machine machines utilize filters to separate the grounds of coffee when they pass through the hot water. The filter is also an essential component of the machine's temp control, since it stops overheating.

A filter can also help with flavor because it allows for an extended flowering time. This allows the beans to let their nuances out, and improves extraction.

However it is crucial to remember that even a top filter can result in a poor cup of coffee, since the quality of the beans and extraction are vital.

It's here that the magic takes place. This is the reason why espresso tastes so good. The grouphead (also called the brewhead) is where you place the portafilter, the thingy used to place the coffee grounds into, when making espresso.

Steam-driven espresso machines make use of hot water that is heated inside an airtight vessel to create steam. The steam then moves hot water through the grounds of the coffee under pressure. These types of machines are generally less expensive and simpler to maintain than pumps-driven models. They are however limited in their ability to create the ideal conditions for brewing since they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

In recent years, compressed air-driven espresso machines have been gaining popularity. They utilize an air compressor to force hot water through grounds and are more portable than electric steam-driven machines.