24 Hours For Improving Machine Espresso How Does compact espresso machine ?

Machine espresso uses precision pressure and incredible filter technology to produce the perfect cup of coffee. 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 that of making drip coffee. However the pressure is the main difference.

The Group Head

As the name implies the group head is where you insert your portafilter when brewing espresso. It distributes water into the portafilter and controls the pressure of the extraction. There are many different kinds of group head each with its unique advantages and disadvantages. Some are designed for stability of temperature while others are built to handle pre-infusion. Others are built to control the lever. Some have a combination, such as the E61. This is a favorite among baristas since it provides multiple advantages in a single package.

As you can see from the photo above the group head is fitted with several notches. The portafilter is placed inside these notches, and then twist the head to lock it. There is also a gasket of rubber in the notches to help create an airtight seal when you insert your portafilter into the machine. The notches permit an exact placement of the portafilter. This is crucial to ensure a consistent extraction.

The group head does not just allow you to place your portafilter easily but also maintains a constant temperature. It does this by cycling hot water through the brew container and around the portafilter, making sure that it is always at the correct temperature to extract. It is important to remember that even a tiny difference can make the difference between a good and a great espresso.

The Pump

In contrast to manual piston machines that use a lever to pressurize water, Rotary espresso machines rely on motorized pumps to provide the nine atmospheric bars of pressure necessary to extract espresso. The pressure builds by drawing tap water from a reservoir, and pumping it through a heat exchanger before being shot through the ground coffee in the group head.

Pumps are typically less expensive and last for longer than piston-driven machines. However, both types of machines are susceptible to degrading because of excessive use and poor cleaning. Pumps are also more complicated mechanically, and can add to the cost of even simple models.

Some espresso machines eliminate the pump completely and employ steam pressure to create espresso. This can lead to over-extraction as the boiler that produces steam also heats the water until it comes to a boil. Additionally, these machines frequently have to restore their pressure between cups, which takes time and energy.

A majority of espresso machines use an rotary or vibrating pump, which has a vibration model using a vibrating disc to create the pressure and a rotary model pushing hot water through the grounds under high speed. Both models are capable of producing excellent espresso, however rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler will heat the water to the right temperature for extraction. The steam that is produced will eventually reach the portafilter, which is a container for espresso grounds. The steam is then channeled into the cup. The steam causes enough pressure to push the grounds of coffee through. This results in a whipped-up the top of the espresso. This is one of the hallmarks of a great espresso.

There are three different types of espresso machines, each with different pumps and brew temperature. There are a variety of ways that the brew may be controlled, as well as the dimensions of the cup the machine can make.

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

The most common espresso maker is a semi-automatic one that has an electric pump. When people think of espresso machines, they imagine these machines. With a semi-automatic machine, you grind the beans and then tamp them by hand. The pump provides regulated water flow and pressure. This is a great compromise between the human touch and the mechanized accuracy.

The Filter

Espresso machines typically use filters that separate the grounds of the coffee from the hot water. The filter is also a vital component of the temperature control system as it prevents the machine from overheating.

A filter also helps with flavor because it allows for a longer flowering period. This allows the beans to release their flavors and provides an opportunity for better extraction.

It is important to remember that even the finest filter can produce a bad cup of coffee. The quality of the beans and the extraction, remain crucial.

It's in this area that the magic takes place. This is what makes espresso taste so good. The grouphead (also known as the brewhead) is where you put the portafilter, the thingy that you use to put the coffee grounds in, when making espresso.


In the steam-driven espresso machine hot water is heated in an airtight container to create steam. Steam then pushes the hot water through the grounds at a high pressure. These types of machines tend to be less expensive and simpler to maintain than pumps-driven models. They are however limited in their ability to create the ideal conditions for brewing since they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

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