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The 9 Things Your Parents Taught You About Machine Espresso
How Does Machine Espresso Work?

Machine espresso uses precision pressure and mind-blowing filter technology to create the delicious coffee we enjoy. What exactly is it?

To make espresso hot water is pushed under pressure through finely ground coffee. The process is similar to making drip coffee, but the difference is in the pressure.

The Group Head

The name implies, the group head is where you place your portafilter while brewing espresso. It disperses water in the portafilter and regulates the pressure during the extraction. There are many different types of group heads, each with its own advantages and drawbacks. Some are focused on temperature stability, while others on pre-infusion capabilities, while others are designed to control the lever. Some come with a combination of both, such as the E61. This is a preferred choice for baristas since it provides multiple benefits in one package.

As you can see in the above image The group head features several notches to place your portafilter before twisting it with your hands to secure it. There is also a rubber gasket in the notches and helps to create the seal when you insert your portafilter into the machine. The notches on the head allow for an exact positioning of the portafilter which is crucial to ensure an even extraction.

Apart from allowing you effortlessly insert your portafilter the group head is also responsible to maintain an even temperature. It does this by cycling hot water through the brew container and around the portafilter, ensuring that it's always at the correct temperature to extract. This is important because even a small difference in temperature can mean the difference between good and excellent espresso.

The Pump

The motorized pumps that are used in espresso machines that rotate provide the nine atmospheric bar pressure needed for espresso extraction. This differs from manual piston machines that use levers. The pressure builds by removing tap water from a reservoir and pumping it through a heat exchanger before being pumped through the ground coffee in the group head.

Pumps tend to be less expensive and last for longer than piston-driven machines. However, both kinds of machines can degrade due to overuse and inadequate cleaning. Pumps are also more complicated mechanically, which can increase the cost of even simpler models.

Some espresso machines make use of steam pressure instead of a pump for brewing espresso. coffeee can lead to over-extraction as the boiler that makes steam also heats the water until it comes to a boil. Additionally the machines often have to restore their pressure between cups, which takes time and energy.


Many espresso machines utilize the rotary or vibration pump, with a vibrating model using a vibrating disc that generates the pressure and an rotary model that pushes hot water through the grounds at high speed. Both machines produce great espresso however rotary machines tend to be more quiet, durable and less likely to break down.

The Boiler

The boiler is what heats the water to the perfect temperature to extract. The steam created will eventually reach the portafilter, which contains the espresso coffee grounds. It is then funneled into the cup. During this process the steam generates enough pressure to push the coffee grounds through. This creates a crema on the top of the espresso. This is one of the hallmarks of a good espresso.

There are three types of espresso makers, which differ in the type of pump they use and the degree of heat that the brew is. There are a variety of ways that the brew may be controlled as well as the dimensions of the cup the machine can make.

The first espresso machines were steam-types. They had a single boiler to make both steam and brew, but the pressure they could produce was not very high - two bars of atmospheric pressure maximum. The coffee tasted bitter and burned. The modern espresso machine was created by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.

The most common espresso machine is a semiautomatic with an electric pump. These are the things people think of when they think of an espresso machine. If you have a semi-automatic machine you need to grind the beans and tamp them by hand, but the pump is able to regulate the flow of water and pressure. This is an excellent combination of human control and mechanized consistency.

The Filter

Espresso machines usually have a filter that separates the grounds of the coffee from hot water. The filter is also an essential part of the machine's temperature control, since it helps to prevent overheating.

It also improves flavor as a filter can allow for a longer bloom time. This allows beans to release their flavor and gives an opportunity for better extraction.

However, it is important to keep in mind that even a high-quality filter can produce a bad cup of coffee, as the quality of the beans and extraction is vital.

This is where the magic happens, it's what makes an espresso really taste great. The grouphead, often called the brewhead, is where the portafilter (the device you put the ground coffee into) sits when you're making espresso.

Steam-driven espresso machines use hot water that is heated in an airtight container to make steam. The steam then pushes hot water through grounds of the coffee under pressure. These types of machines tend to be less expensive and easier to maintain than pumps-driven models. However, they are not as efficient in their ability to create the ideal conditions for brewing as they only operate at 1-1.5 bars of pressure. However, the perfect shot requires 9-10 bars.

In recent years, espresso machines driven by compressed air-pump have become increasingly popular. They use an air-compressor to push hot water across the ground. They are also more mobile than steam-driven electric espresso machines.

Website: https://www.coffeee.uk/categories/espresso-coffee-machines