How Does Machine Espresso Work?

The machine espresso makes use of precise pressure, as well as a filter technology that is mind-blowing to make the coffee you love. What exactly is it?

Espresso is created by forcing hot water at high pressure through finely-ground coffee. The process is similar to making drip coffee however the main difference lies in the pressure.

The Head of the Group

The group head is the portafilter that you place in the espresso maker when making it. It is responsible for dispersing the water into the portafilter and controlling the pressure that results from the extraction. There are numerous kinds of group heads, each with its own advantages and disadvantages. Some are specifically designed for stability of temperature while others are designed to handle pre-infusion. Others are built to control the lever. Some contain a variety of features, such as the E61, which is considered the standard choice for many baristas for its ability to provide multiple benefits in one package.

As you can see in the above image, the group head has many notches in which you can place your portafilter and twist it by hand to lock it in. There is also a gasket of rubber that is a part of the notches and helps create a seal when you insert your portafilter into the machine. The notches on the head allow for an exact placement of the portafilter, which is crucial for an efficient extraction.

In addition to allowing you easily insert your portafilter, the group head is also responsible to maintain an even temperature. This is done by cycling hot water around the portafilter, and through the brew-basket to ensure that the temperature is at the right level for extraction. It is crucial to keep in mind that even a slight difference can make the difference between a good and a great espresso.

The Pump

In contrast to piston machines that are manually operated, that use a lever to pressurize water, Rotary espresso machines rely on motorized pumps to provide the nine atmospheric bars of pressure required for espresso extraction. 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, although both types of machines may become damaged due to excessive use and poor cleaning. Pumps are also more complicated mechanically, which can increase the price of even the simpler models.

Some espresso coffee machines for sale machines remove the pump completely and instead use steam pressure to brew espresso. The disadvantage of this is that the boiler that produces steam also raises the temperature of the water until it reaches boiling and can result in excessive extraction. Additionally the machines often have to rebuild their pressure between cups, which requires time and energy.

Many espresso machines utilize either a rotary or vibration pump, with a vibrating model that uses a vibrating disc to create the pressure, and an rotary model that pushes hot water through the grounds under high speed. Both types of machines can make a great espresso, but rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is what will heat the water to the ideal temperature for extraction. The resultant steam then reaches the portafilter which holds ground professional espresso machine beans and is then pumped into the cup. In this process, the steam creates pressure that pushes through the grounds of the coffee machines espresso. This results in a whipped-up top of the espresso. This is one of the main characteristics of a good espresso.

There are three kinds of espresso makers. They differ in the type of pump they use and how hot the brew is. There are also different ways in which the brew could be controlled, as well as the dimensions of the cup the maker can create.

The first espresso machines were steam-types. The earliest espresso machines were steam types. The coffee tasted bitter and burnt. The modern espresso machine was designed by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso maker is a semi-automatic machine with an electric pump. These are the images people have when they think of an espresso maker. With a semi-automatic machine, you have to grind the beans and then tamp them by hand. However, the pump regulates the flow of water and pressure. This is an excellent compromise between human touch and the mechanized quality.

The Filter

Typically, espresso machines employ filters to separate the grounds of the coffee as they go through the hot water. The filter is also a crucial element of the temperature control system as it keeps the machine from overheating.

A filter also improves flavor, as it permits a longer flowering period. This helps the beans release their flavor and gives an opportunity for a better extraction.

It is important to remember that even the best cheap espresso machine filter can make a bad cup of coffee. The quality of the beans, and the extraction process, remain crucial.

It's in this area that the magic occurs. This is what makes espresso taste so delicious. The grouphead, often referred to as the brew head, is the place where the portafilter (the device you put the coffee grounds into) is placed when you're making espresso.

Steam-driven espresso machines use hot water that is heated in an airtight vessel to create steam. The steam then pushes hot water through grounds of coffee at high pressure. They are less expensive and are easier for the user to maintain than pumps-driven models. They are however limited to create the perfect conditions for brewing, as they operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

In recent years, compressed air-driven espresso machines have become more popular. They use an air compressor to push the hot water through the grounds and are much more portable than steam-driven electric machines.