How Does Machine Espresso Work?

Machine espresso uses precision pressure and incredible filter technology to produce the perfect cup of coffee. What exactly is it?

Espresso is created by forcing hot water under pressure through finely-ground coffee. The process is similar to that of making drip coffee. However the pressure is the primary difference.

The Head of the Group

As the name suggests, the group head is the place you put your portafilter in when brewing espresso. It disperses water in the portafilter, and regulates the pressure during the extraction. There are various kinds of group head each with its particular advantages and disadvantages. Some are focused on temperature stability, while others on pre-infusion options, and others are designed to control the lever. There are some that come with a range of features, such as the E61, which is the classic choice among many baristas due to its capacity to offer multiple perks in a single package.

As you can see from the image above, the group head is fitted with a variety of notches. It is possible to place your portafilter in these notches, then twist the head to lock it. A gasket made of rubber is positioned inside the notches to help create a seal when you insert your portafilter. The notches permit the precise placement of the portafilter. This is vital for an efficient extraction.

The group head does not just allow you to put in your portafilter easily however, it also keeps a constant temperature. This is accomplished by cycling hot water around the portafilter, and through the brew-basket to ensure that the temperature is at the right level to extract the coffee. This is vital, because even a few degrees can make the difference between excellent and great espresso.

The Pump

The motorized pumps used in espresso machines that rotate provide the nine atmospheric bar pressure needed to extract espresso. This is different from manual piston machines that use levers. This pressure is built up 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 deteriorate because of excessive use and insufficient cleaning. Pumps are also more complex mechanically, which can increase prices of even simplest models.

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

A majority of espresso machines use the rotary or vibration pump, which is a vibration model using a rotating disc that generates the pressure, and an rotary model that pushes hot water through the grounds under high speed. Both machines can make excellent espresso, however rotary machines are quieter, more durable and less likely to break down.

The Boiler

The boiler is the element that heats water to the ideal temperature to extract. The steam that is produced is then directed to the portafilter, which contains the espresso coffee grounds. It is then poured into the cup. The steam is able to create enough pressure to push the coffee grounds through. This results in a whipped-up the top of the espresso. This is one of the hallmarks of a great espresso.

There are three types of espresso makers, and they differ in the type of pump they employ and how hot the brew is. There are various ways to control the brew as well as the size of cup that can be produced by the machine.

The first espresso machines were steam-types. The first espresso machines were steam types. The coffee tasted bitter and burnt. The modern espresso machine was created by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most well-known espresso maker is a semi-automatic machine with an electric pump. When people think of espresso machines, they picture these machines. With a semi-automatic espresso machine, you grind the beans and then tamp them by hand. The pump controls the flow of water and pressure. This is an excellent solution that combines human control with mechanised reliability.

The Filter

Typically, espresso machines use filters to separate the grounds of coffee as they move through the hot water. The filter is also an essential part of the temperature control system since it helps prevent the machine from overheating.

It also aids in flavor, as a filter lets you enjoy a longer bloom time. This allows beans to release their nuances and gives the chance for better extraction.

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

It's in this area that the magic occurs. This is what makes espresso taste so delicious. The grouphead (also known as the brewhead) is where you place the portafilter, the device that you use to put the grounds of your coffee into while making espresso.

Steam-driven espresso machines use hot water that is heated in an airtight container to create steam. The steam then pushes hot water into the grounds of the coffee espresso machines under pressure. These types of machines are typically less expensive and easier to maintain than pump-driven models. However, they are limited in their capacity to create the ideal conditions for brewing since they operate at 1-1.5 bars of pressure. The perfect shot requires 9-10 bars.

In recent years, compressed air-driven espresso coffee maker machines have become more popular. They use an air compressor to force the hot water through the grounds, and are far more portable than steam-driven electric machines.