10 Facts About Machine Espresso That Will Instantly Put You In An Upbeat Mood How Does Machine Espresso Work?

Machine espresso uses precision pressure and mind-blowing filter technology to create the delicious coffee we enjoy. How exactly does it work?

In order to make espresso hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee. However it is the pressure that makes the main difference.

The Group Head

As the name implies the group head is the place you place your portafilter when making espresso. It is responsible for dispersing water into the portafilter and then controlling the pressure of the extraction. There are many different kinds of group head each with its unique advantages and disadvantages. Some are specifically designed for temperature stability while others are specifically designed to handle pre-infusion. Others are made to control the lever. Some include a combination like the E61. This is a popular choice among baristas since it provides multiple benefits in one package.

As you can see from the above photo, the group head has a number of notches. The portafilter is placed into these notches and twist the head to secure it. There is also a gasket made of rubber in the notches, which helps create a seal when you insert your portafilter into the machine. The notches allow for precise placement of your portafilter. This is crucial to ensure a consistent extraction.

In addition to allowing you to easily place your portafilter in, the group head is also responsible to ensure that the temperature remains even. It does this by circulating hot water through the brew pan and around the portafilter, making sure that it is always at the correct temperature to extract. It is crucial to keep in mind that even a slight difference can make the difference between a decent and a excellent espresso.

The Pump

Unlike manual piston machines, which rely on a lever to pressurize water, the rotary espresso machines use motorized pumps to provide the nine atmospheric bars of pressure that are required for espresso extraction. This pressure builds up by drawing tap water from a reservoir, and pumping it through a heat exchanger prior to it is shot through the ground coffee in the group head.

Pumps are generally more affordable and last longer than piston-driven machines. However, both kinds of machines are susceptible to degrading because of excessive use and inadequate cleaning. Pumps are also more complicated mechanically, and can add to the price of even the most basic models.

Certain espresso machines do away with the pump completely and instead use steam pressure to brew espresso. This could lead to over-extraction since the boiler that produces steam also heats the water until it comes to a boil. The machines also need to continuously rebuild their pressure between cups. This takes energy and time.

A majority of espresso machines utilize the rotary or vibration pump. A vibration model makes use of a rotating disk to generate pressure, while a circular model pushes hot liquid through the ground at high speed. Both types of machines can produce an excellent espresso, but the rotary models are quieter and more durable than vibration pumps.

The Boiler

The boiler makes the water warm to a temperature that is ideal to extract. The resultant steam then reaches the portafilter which holds ground espresso beans and is then pumped down into the cup. During this process the steam generates enough pressure to push the grounds of coffee through. This results in a layer of crema that is then poured over. This is one of the main characteristics of a great espresso.

There are three types of espresso makers. 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 can be controlled and the size of the cup that the machine can produce.


The first espresso machines were steam-based. The earliest espresso machines were steam types. This led to the coffee tasting bitter and burnt. This is why the Milanese producers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most common espresso maker is a semi-automatic device with an electric pump. These are what people imagine when they think of an espresso machine. With a semi-automatic machine you grind the beans and tamp them yourself but the pump provides regulated water flow and pressure. This is a fantastic compromise between human control and mechanised accuracy.

The Filter

Typically, espresso machines employ filters to separate the coffee grounds as they pass through the hot water. The filter is also an essential component of the temperature control system as it prevents the machine from overheating.

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

However it is crucial to keep in mind that even a good filter could result in a bad cup of coffee, as the quality of the beans and extraction is important.

It's here that the magic takes place. This is the reason why espresso tastes so good. The grouphead, sometimes called the brew head, is where the portafilter (the device you put the coffee ground into) is placed when making espresso.

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

In recent years, espresso machines powered by a compressed air compressor have become increasingly popular. They make use of an air compressor to push hot water across the ground, and are more mobile than steam-driven electric espresso machines.