How Does Machine Espresso Work?

Machine espresso utilizes precise pressure and mind-blowing filter technology to create the coffee we love. What exactly is it?

To make 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 insert when brewing espresso. It disperses water into the portafilter, and Machine espresso regulates the pressure of the extraction. There are many different kinds of group head each with its own advantages and drawbacks. Some are designed to provide stability of temperature while others are designed to handle pre-infusion. Some are designed to control the lever. Some include a combination like the E61. This is a preferred choice for baristas since it provides multiple advantages in one package.

As you can see from the picture above, the group head is fitted with a variety of notches. You place your portafilter into these notches and twist the head to secure it. A rubber gasket is located within the notches to create a seal while you insert your portafilter. The notches allow for the precise placement of the portafilter. This is crucial to ensure an accurate extraction.

The group head does not just allow you to insert your portafilter easily, but it also maintains an even temperature. It does this by cycling hot water through the brew container and around the portafilter, making sure that it's always at the right temperature for extraction. This is important because just a few degrees could make the difference between a excellent and great espresso.

The Pump

Motorized pumps in rotary espresso machines supply the nine atmospheric bar pressure needed for espresso extraction. This is different from manual piston machines that rely on levers. The pressure is built by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are typically more affordable and last longer than piston-driven machines. However, both kinds of machines can deteriorate because of excessive use and poor cleaning. They also add mechanical complexity which can result in costly prices for even the most basic models.

Certain espresso machines do away with the pump completely and use steam pressure to brew espresso. This can lead to over-extraction as the boiler that produces steam also heats the water until it comes to a boil. These machines also have to constantly rebuild their pressure between cups. This requires energy and time.

A majority of espresso machines use either a rotary or vibration pump, which is a vibration model using a rotating disc that generates the pressure, and Machine Espresso rotating models that push hot water through the grounds at high speed. Both machines can make great espresso but rotary machines are more stable, quieter and less likely to fail.

The Boiler

The boiler is the one that is used to heat thimproves extraction.

However, it is important to remember that even a high-quality filter could result in a bad cup of coffee as the quality of the beans and extraction is essential.

This is where the magic happens, it's the thing that makes espresso taste good. The grouphead (also called the brewhead) is where you place the portafilter, the thingy used to place the grounds of coffee and espresso maker into when making espresso.

In a steam-driven espresso machine, hot water is heated in an airtight container to produce steam, which then pushes the hot water through the grounds at a high pressure. These types of machines tend to be less expensive and easier to maintain than pumps-driven models. However, they are limited in their ability to provide the ideal brewing conditions, as they only operate at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bar.

In recent times, espresso coffee machines uk 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. They are also more mobile than steam-driven electric espresso machines.