How Does Machine Espresso Work?

The machine espresso is made using precision pressure, and filtering technology that is amazing to make the coffee you enjoy. What exactly does it work?

To make an espresso, hot water is forced under high 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

The group head is the portafilter you place in the espresso maker when making it. It disperses water in the portafilter, and then regulates the pressure of extraction. There are numerous kinds of group heads each with their own advantages and drawbacks. Some are focused on temperature stability, whereas others on pre-infusion capabilities, while others are designed to control the lever. There are some that have a combination of features, such as the E61, which is considered the most popular choice among baristas due to its ability to offer multiple perks in one package.

As you can see in the image above The group head features many notches in which you can place your portafilter and then twist it by hand to secure it. There is also a gasket made from rubber in the notches and helps create an airtight seal after inserting your portafilter into the machine. The notches on the head allow for an exact position of the portafilter which is necessary for an efficient extraction.

In addition to allowing you to easily insert your portafilter, the group head is responsible to maintain an even temperature. It does this by cycling hot water through the brew container and around the portafilter, making sure that it is always at the correct temperature to extract. This is important, as just a few degrees could make the difference between good and great espresso.

The Pump

In contrast to manual piston machines which rely on a lever that pressurize water, the rotary espresso machines use motorized pumps to deliver the nine atmospheric bars of pressure necessary to extract espresso. The pressure is created by drawing tap water from a reservoir, and pumping it through a heat exchanger before being shot through the ground coffee inside the group head.

Pumps are generally cheaper and last longer than piston-driven machines. However, both types of machines can degrade because of excessive use and poor cleaning. They also add mechanical complexity that can lead to costly prices for even the most basic models.

Certain espresso machines can eliminate the pump completely and instead make use of steam pressure to make espresso. This can cause over-extraction because the boiler that produces steam also heats the water until it comes to a boil. Additionally these machines are often required to restore their pressure between cups, which takes time and energy.

Many espresso machines use a rotary or vibration pump. A vibration model uses a vibrating disk to generate pressure, while the Rotary model pushes hot coffee through the ground at a high speed. Both machines can make great espresso, but rotary machines are more stable, quieter and less likely to break.

The Boiler

The boiler is the part that heats water to an optimal temperature for extraction. The steam that is created reaches the portafilter, which contains the Italian espresso machine coffee grounds. It is then funneled into the cup. During this process the steam is able to create enough pressure to push the coffee grounds through. This creates a layer crema on top. This is a sign of a good espresso.

There are three distinct types of espresso machines, each having distinct pumps and brew temperature. There are many ways to control the brew as well as the size of the cup that can be produced by the machine.

The first espresso machines were steam-type. They used one boiler to create both steam and brew however, the pressure they could produce was very low - just two bars of atmospheric pressure at the most. The coffee tasted bitter and burnt. This is why the Milanese producers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most commonly used espresso coffee machines uk maker is a semi-automatic one that has an electric pump. When people think of espresso machines, they imagine these machines. With a semi-automatic machine, you grind the beans and tamp them by hand. However, the pump controls the flow of water and pressure. This is a great solution that combines human control with mechanized reliability.

The Filter

Espresso machines usually have filters that separate the grounds of the coffee from the hot water. The filter is also a crucial component of the temperature control system since it helps prevent the machine from overheating.

It also aids in flavor as a filter allows for a more prolonged bloom phase. This allows the beans to let their nuances out, and allows for a better extraction.

It is important to remember that even the most efficient filter can produce a bad cup of coffee. The quality of the beans, and the extraction process, are still crucial.

It's in this area that the magic occurs. This is what makes espresso taste so delicious. The grouphead (also called the brewhead) is where you place the portafilter, which is the thingy used to place the grounds of your best coffee espresso machine into when 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 at a high pressure. These types of machines are typically cheaper and easier to maintain than pumps-driven models. However, they are limited in their ability to create the perfect 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 machines have been gaining popularity. They utilize an air compressor to push hot water into the grounds and Italian Espresso Machine are much more portable than electric steam-driven machines.