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Don't Buy Into These "Trends" About Machine Espresso
How Does Machine Espresso Work?

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

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

The Group Head

The group head is the portafilter is inserted when you are making espresso. It is responsible for dispersing water into the portafilter before controlling the pressure of the resulting extraction. There are a variety of types of group head each with its own advantages and disadvantages. Some are focused on temperature stability, others on pre-infusion capabilities, and still others are designed to control the lever. Some are a combination, such as the E61. This is a popular choice among baristas because it offers multiple benefits in one package.

As you can see from the above photo, the group head has a number of notches. You place your portafilter inside these notches, and then turn the head around to secure it. There is also a rubber gasket that resides inside the notches and helps to create an airtight seal after inserting your portafilter into the machine. The notches on the head allow for a precise positioning of the portafilter which is necessary for an efficient extraction.

In addition to allowing you easily insert 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 to ensure that the temperature is constant to extract the coffee. It is important to note that even a small deviation can make the difference between a good and great espresso.

The Pump

The motorized pumps used in espresso machines that rotate provide the nine atmospheric bars of pressure required for espresso extraction. This is different from manual piston machines which use levers. The pressure is created by pumping water through a heat exchanger and then through the ground coffee.

Pumps tend to be less expensive and last longer than piston-driven machines. However, both types of machines can degrade due to overuse and poor cleaning. They also create mechanical complexity and can lead to the cost of even the most basic models.

Some espresso machines employ steam pressure instead of a pump to brew espresso. This can cause over-extraction because the boiler that produces steam also heats the water until it comes to a boil. The machines must also constantly rebuild their pressure between cups. This requires energy and time.

A majority of espresso machines use either a rotary or vibration pump, which has a vibration model that uses a vibrating disc to create pressure and the rotary model pushing hot water through the grounds at high speed. small espresso machine can make great espresso, but rotary machines are quieter, more durable and less likely to break down.

The Boiler

The boiler is the one that will heat the water to the right temperature for extraction. The steam that is produced is then directed to the portafilter, which contains the espresso coffee grounds. The steam is then channeled into the cup. The steam generates enough pressure to push the coffee grounds through. This results in a layer crema on top. This is one of the hallmarks of a great espresso.

There are three kinds of espresso makers. They differ in the type of pump they use and the degree of heat that the coffee is. There are a variety of ways to control the brew and the size of cup that can be produced by the machine.

The first espresso machines were steam-types. They had a single boiler to make both steam and brew however the pressure they were able to produce was very low - just two bars of atmospheric pressure maximum. This led to the coffee tasting bitter and burnt. The modern espresso machine was designed by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most well-known espresso machine is a semiautomatic model 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 by yourself, but the pump regulates the water flow and pressure. This is a great compromise between the human touch and the mechanised quality.

The Filter

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

It also improves flavor, since a filter can allow for a longer bloom phase. This helps the beans release their flavor and gives an opportunity to improve extraction.

However it is crucial to keep in mind that even a high-quality filter could result in a bad cup of coffee as the quality of the beans and extraction is still essential.


It's here that the magic happens. This is the reason why espresso tastes so delicious. The grouphead, often referred to as the brewhead, is where the portafilter (the thingy you put the coffee ground into) sits when you're making espresso.

In a steam-driven espresso machine hot water is heated in an airtight tank to create steam. This then pushes the hot water through the grounds with high pressure. They are less expensive and are easier for the user to maintain than pumps-driven models. They are however limited to create the perfect conditions for brewing since they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

In recent times, espresso machines powered by a compressed air pump have become increasingly popular. They utilize an air compressor to force hot water through the grounds, and are far more portable than electric steam-driven machines.