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10 Machine Espresso-Related Meetups You Should Attend
How Does Machine Espresso Work?

The machine espresso utilizes precision pressure, and a filter technology that is awe-inspiring to create the coffee you enjoy. How does it work exactly?

Espresso is made by pushing hot water under pressure through finely-ground coffee. The process is similar to making drip coffee. However, the pressure is the main difference.

The Head of the Group

As the name suggests, the group head is where you place your portafilter when making espresso. It is responsible for dispersing water into the portafilter and then controlling the pressure that results from the extraction. There are a variety of types of group head, each with their distinct advantages and drawbacks. Some are designed for temperature stability while others are built to handle pre-infusion. Others are built to control the lever. There are also some that include a mix of features, like the E61, which is considered the classic choice among many baristas for its ability to offer multiple benefits in one package.

As you can see in the above image the group head is made up of numerous notches that you can place your portafilter and then twist it by hand to lock it in. A rubber gasket is located inside the notches, which helps create a seal as you insert your portafilter. The notches on the head allow for an exact location of the portafilter which is crucial for an efficient extraction.

In addition to allowing you to effortlessly insert your portafilter the group head is responsible for maintaining a consistent temperature. It does this by circulating hot water through the brew basket and around the portafilter, making sure that it's always at the right temperature for extraction. This is important, as just a few degrees could mean the difference between excellent and great espresso.

The Pump

Contrary to manual piston machines that use a lever to pressurize water, rotary espresso machines rely on motorized pumps to supply the nine atmospheric bars of pressure necessary for espresso extraction. This pressure is generated by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are generally less expensive than piston-driven machines, and tend to last longer, however both types of machines could degrade with overuse and insufficient cleaning. They also add mechanical complexity that can lead to the cost of even the simplest models.

Some espresso machines use steam pressure instead of a pump to brew espresso. This can lead to over-extraction as the boiler that produces steam also causes the water to boil. In addition these machines typically have to rebuild their pressure between cups, which takes time and energy.

Many espresso machines utilize either a rotary or vibration pump, with a vibration model that uses a vibrating disc to generate the pressure, and a rotary model pushing hot water through the grounds at high speed. Both types of machine are capable of producing excellent espresso, however rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the one that makes the water warm to the right temperature to extract. The steam that is produced is then directed to the portafilter, which holds the espresso grounds. It is then poured into the cup. In this process, the steam creates pressure to push through the coffee grounds. This creates a foam on top of the espresso. This is one of the hallmarks of a good espresso.

There are three different types of espresso machines, each having a different type of pump and the temperature of the brew. There are different ways to control the amount of brew, as well as the size of the cup that can be made by the machine.

read on were steam-type. home espresso machine were steam-type machines. This led to the coffee tasting bitter and burnt. This is the reason why Milanese producers Luigi Bezzerra and Desiderio Pavoni developed the modern espresso machine.

The most popular espresso machine is a semiautomatic that has an electric pump. These are the images people have when they think of an espresso machine. Semi-automatic machines require you to grind and tamp the beans by yourself however the pump controls the flow of water and pressure. This is a perfect solution that combines human control with mechanised accuracy.

The Filter

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

Filters also aid in flavor since it allows for a longer flowering period. This allows the beans to release their flavor and improves extraction.

However, it is important to keep in mind that even a good filter can make a terrible cup of coffee as the quality of the beans and extraction are crucial.

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


In a steam-driven espresso machine, hot water is heated in an airtight tank to create steam, which then pushes the hot water through the grounds under high pressure. These types of machines tend to be cheaper and easier to maintain than pumps-driven models. They are however limited for creating 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, espresso machines driven by a compressed air pump have become increasingly popular. They make use of an air compressor to push hot water through the ground. They are also more mobile than electric steam-driven espresso machines.

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