The No. #1 Question That Everyone In Machine Espresso Should Know How To Answer How Does Machine Espresso Work?

The machine espresso makes use of precise pressure, as well as a filtering system that is awe-inspiring to make the coffee you love. What exactly does it work?

Espresso is produced by pushing hot water under pressure through finely ground coffee. The process is similar to making drip coffee however the main difference lies in the pressure.

The Head of the Group

The name implies the group head is the place you put your portafilter in when brewing espresso. It is responsible for dispersing water into the portafilter and then controlling the pressure of the extraction. There are several different types of group head, each with their particular advantages and disadvantages. Some are focused on temperature stability, while others on pre-infusion capabilities, and still others are designed to control the lever. Some come with a combination of both, such as the E61. This is a popular choice among baristas since it provides multiple benefits in one package.

As you can see from the image above the head of the group is fitted with a variety of notches. It is possible to place your portafilter inside these notches, and then turn the head around to secure it. There is also a gasket of rubber in the notches and helps create the seal when you insert your portafilter into the machine. The notches on the head permit an exact positioning of the portafilter which is crucial for an efficient extraction.

The group head does not just allow you to place your portafilter easily but also maintains a constant temperature. It does this by cycling hot water through the brew basket, and around the portafilter, making sure that it is always at the correct temperature for extraction. It is important to note that even a tiny variation can mean the difference between a decent and a great espresso.

The Pump

In contrast to piston machines that are manually operated, which use a lever to pressurize water, rotary espresso machines rely on motorized pumps that provide the nine atmospheric bars of pressure needed for espresso extraction. best espresso machine builds up by removing tap water from a reservoir, and pumping it through a heat exchanger before it is shot through the ground coffee in the group head.

Pumps tend to be less expensive than piston-driven models, and they tend to last longer, although both types of machine can get damaged through overuse and lack of cleaning. They also add mechanical complexity and can lead to an expensive price for even the most basic models.

Some espresso machines can eliminate the pump completely and utilize steam pressure to make espresso. This could lead to over-extraction since the boiler that produces steam also causes the water to boil. Additionally the machines often have to rebuild their pressure between cups, which takes time and energy.

Many espresso machines utilize either a rotary or vibration pump, which has a vibration model that uses a vibrating disc that generates the pressure and a rotary model pushing hot water through the grounds under high speed. Both machines produce great espresso, but rotary machines are more stable, quieter and less likely to break down.

The Boiler

The boiler is the one that heats the water to the perfect temperature to extract. The resulting steam reaches the portafilter that contains the ground espresso coffee and is then pumped into the cup. During this process, the steam creates pressure and pushes through the coffee grounds. This produces a layer of crema on top. This is one of the hallmarks of a great espresso.

There are three types of espresso makers, which differ in the kind of pump they use and the degree of heat that the coffee is. There are different ways in which the brew can be controlled as well as the size of the cup that the machine can make.


The first espresso machines were steam-types. They utilized only one boiler to make steam and brew, but the pressure they could create was minimal - two bars of atmospheric pressure at the most. The coffee tasted bitter and burned. This is the reason why Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most commonly used espresso maker is a semiautomatic machine that has an electric pump. When people think of espresso machines, they imagine these machines. With a semi-automatic machine, you must grind the beans and tamp them by hand. However, the pump provides regulated water flow and pressure. This is an excellent compromise between human touch and the mechanized quality.

The Filter

Espresso machines typically use a filter that separates the grounds of coffee from hot water. The filter is also a vital component of the machine's temp control, since it stops overheating.

A filter also helps with flavor as it allows for a longer flowering period. This allows the beans to release their flavors and provides an opportunity for a better extraction.

It is important to remember that even the best filter could result in a poor cup of coffee. The quality of the beans, and the extraction process remain vital.

It's in this area that the magic occurs. This is the reason why espresso tastes so good. The grouphead (also known as the brewhead) is where you put the portafilter - the thingy used to place the grounds of your coffee into when making espresso.

Steam-driven espresso machines use hot water that is heated inside an airtight container to produce steam. The steam then moves hot water through the grounds of coffee at high pressure. These machines are less expensive and easier to maintain than pumps-driven models. They are however limited to create the ideal conditions for brewing as they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

In recent years, compressed air-pump-driven espresso machines have been gaining popularity. They use an air-compressor to force hot water through the ground and are much more mobile than steam-driven electric espresso machines.