14 Businesses Doing A Great Job At Machine Espresso How Does Machine Espresso Work?

Machine espresso makes use of precise pressure and incredible filter technology to produce the coffee we love. How 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 major difference.

The Group Head

The group head is the portafilter that you put in when making espresso. It distributes water into the portafilter and regulates the pressure of extraction. There are espresso coffee machine for home of group head, each with their unique advantages and drawbacks. Some are designed for stability of temperature while others are specifically designed to handle pre-infusion. Some are designed to control the lever. Some come with a combination of both, like the E61. This is a very popular choice for baristas because it offers multiple advantages in one package.

As you can see from the picture above the group head is fitted with a variety of notches. You can place your portafilter in these notches and then twist the head to secure it. A rubber gasket is located inside the notches, which helps create a seal while you insert your portafilter. The notches on the head allow for an exact location of the portafilter which is vital to ensure an even extraction.

Apart from allowing you easily connect your portafilter, the group head is also responsible for maintaining a consistent temperature. This is achieved by cycling hot water around the portafilter, and through the brew-basket, making sure the temperature is always right to extract the coffee. This is important, as just a few degrees could be the difference between a good and excellent espresso.

The Pump

Unlike manual piston machines, which rely on a lever that pressurize water, Rotary espresso machines rely on motorized pumps that provide the nine atmospheric bars of pressure required to extract espresso. The pressure is created by drawing tap water from a reservoir and pumping it through a heat exchanger prior to being pumped through the ground coffee in the group head.

Pumps are typically less expensive than piston-driven machines, and they tend to last longer. However, both types of machine can degrade with overuse and insufficient cleaning. They also increase the complexity of mechanical systems, which can result in a high price tag on even the most basic models.

Certain espresso machines utilize steam pressure instead of a pump in order to brew espresso. The downside is that the same boiler that produces steam also raises the temperature of water until it reaches boiling and can result in excessive extraction. Additionally the machines often have to rebuild their pressure between cups, which takes time and energy.

Many espresso machines make use of a rotary or vibration pump. A vibration model uses an oscillating disk to create pressure, whereas the rotary model pushes hot water through the ground at high speed. Both types of machines can make excellent espresso, however the rotary models are quieter and more durable than vibration pumps.

The Boiler

The boiler will heat the water to the perfect temperature to extract. The steam that is produced gets to the portafilter which is the container that holds the espresso coffee grounds. It is then poured into the cup. In this process, the steam creates pressure and pushes through the grounds of the coffee. This produces a layer of crema that is then poured over. This is one of the hallmarks of a good espresso.

There are three distinct types of espresso machines, each with a different type of pump and the temperature of the brew. There are different 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-type. 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 common espresso machine is a semiautomatic that has an electric pump. When people think of espresso machines, they picture these machines. Semi-automatic machines require you to grind and tamp the beans by yourself while the pump controls the flow of water and pressure. This is a great compromise between human control and mechanized consistency.

The Filter

Typically, espresso machines employ filters that separate the grounds of coffee when they pass through the hot water. The filter is also an essential component of the machine's temp control, since it stops overheating.


It also helps with flavor as a filter lets you enjoy a longer bloom time. This lets the beans release their flavors, and allows for better extraction.

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

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

In a steam-driven espresso machine, hot water is heated in an airtight tank to create steam. This then pushes the hot water through the grounds under high pressure. These machines are less expensive and easier to maintain than pumps-driven models. They are however limited in their ability to create the perfect 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 use an air compressor to force hot water into the grounds, and are far more portable than electric steam-driven machines.