Maisie Birdwood

How Does Machine Espresso Work?

Machine espresso employs precise pressure and amazing filter technology to make the delicious coffee we enjoy. What exactly is it that makes it work?

Espresso is produced by pushing hot water under high pressure through finely ground coffee. The process is similar to making drip coffee but the major difference is in the pressure.

The Head of the Group

As the name suggests, the group head is where you put your portafilter in when making espresso. It disperses the water into the portafilter, and then regulates the pressure of extraction. There are various kinds of group head, each with their unique advantages and drawbacks. Some focus on temperature stability, others on pre-infusion capabilities, while others are designed to control the lever. Some come with a combination of both, like the E61. This is a favorite among baristas because it offers multiple benefits in one package.

As you can see in the photo above the group head is made up of numerous notches that you can put your portafilter, then twist it with your hands to lock it in. There is also a gasket of rubber that resides inside the notches to help create an airtight seal after inserting your portafilter into the machine. The notches on the head permit a precise position of the portafilter which is crucial for a consistent extraction.

The group head is not just able to allow you to insert your portafilter easily however it also keeps the temperature at a constant level. This is achieved by cycling hot water around the portafilter, and through the brew-basket, making sure that the temperature is constant for extraction. This is important because even a small difference in temperature can mean the difference between good and excellent espresso capsule machine.

The Pump

In contrast to manual piston machines which rely on a lever that pressurize water, Rotary espresso machines rely on motorized pumps to supply the nine atmospheric bars of pressure needed to extract espresso. The pressure is built by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are typically less expensive than piston-driven machines, and tend to last longer, but both types of machines may get damaged through overuse and lack of cleaning. They also make mechanically complex which can result in costly prices for even the simplest models.

Certain espresso home machine machines utilize steam pressure instead of a pump for brewing commercial espresso machine. This could lead to over-extraction since the boiler that makes steam also heats the water bean to cup espresso machine boil. In addition the machines often have to rebuild their pressure between cups, which takes time and energy.

Many espresso machines make use of the rotary or vibration pump. A vibration model uses the vibrating disk to create pressure, while a circular model pushes hot liquid through the ground at a rapid speed. Both machines produce great espresso, however rotary machines are more quiet, durable and less likely to break down.

The Boiler

The boiler heats the water to the ideal temperature to extract. The resultant steam then reaches the portafilter, which contains the ground espresso coffee and is then pumped into the cup. The steam causes pressure to push through the grounds of the coffee. This results in a layer crema that is then poured over. This is one of the main characteristics of a good espresso.

There are three types of espresso makers, and they 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 is capable of making.

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

The most popular espresso machine is a semiautomatic with an electric pump. When people think of espresso machines, they think of these machines. With a semi-automatic machine you grind the beans and then tamp them yourself but the pump controls the flow of water and pressure. This is a great solution that combines human control with mechanized reliability.

The Filter

Typically, espresso coffee machine uk machines have filters that separate the grounds of coffee when they pass through the hot water. The filter is also a crucial element of the temperature control system, because it stops the machine from overheating.

A filter also helps with flavor since it allows for a longer flowering period. This allows beans to release their flavor and gives an opportunity to improve extraction.

It is important to keep in mind that even the best filter can produce a bad cup of coffee. The quality of the beans and the extraction, remain vital.

This is where the magic happens, and it's what makes espresso taste good. The grouphead (also called the brewhead) is where you put the portafilter, the device used to place the grounds of coffee into while making espresso.

In an espresso machine that is driven by steam, hot water is heated in an airtight tank to produce steam, which is then pushed through the grounds at high pressure. These types of machines are generally less expensive and simpler to maintain than pump-driven models. However, they are limited in their ability to produce the perfect conditions for brewing, as they only operate at 1-1.5 bars of pressure. The perfect shot requires 9-10 bars.

In recent years, espresso machines powered by compressed air-pump are becoming increasingly popular. They utilize an air compressor to force hot water into the ground, and are more mobile than steam-driven electric espresso maker espresso machines.