How Does Machine Espresso Work?

The machine espresso utilizes precise pressure, as well as a filtering system that is awe-inspiring to make the coffee espresso machine you enjoy. What exactly is it that makes it work?

To make an espresso, hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee, but the key difference is in the pressure.

The Group Head

The group head is the portafilter that you place in the espresso maker when making it. It disperses water into the portafilter, and regulates the pressure of the extraction. There are several different types of group head each with its unique advantages and disadvantages. Some are designed to provide the stability of temperature while some are designed to handle pre-infusion. Some are designed to control the lever. There are even some that include a mix of features, such as the E61 that is the classic choice among many baristas for its ability to offer multiple perks in a single package.

As you can see from the above photo the group head is fitted with several notches. The portafilter is placed in these notches, then twist the head to lock it. There is also a rubber gasket that is a part of the notches and helps to create an airtight seal after inserting your portafilter into the machine. The notches permit precise placement of your portafilter. This is essential for a consistent extraction.

Aside from allowing you to effortlessly insert your portafilter the group head is also responsible to ensure that the temperature remains even. It does this by cycling hot water through the brew pan and around the portafilter to ensure that it’s always at the right temperature for extraction. This is important, as just a few degrees could make the difference between excellent and great espresso.

The Pump

Motorized pumps in rotary espresso machines provide the nine atmospheric bar pressure that is required to extract espresso. This differs from manual piston machines that rely on a lever. This pressure is generated by pumping water through a heat exchanger and then through the ground coffee.

Pumps are typically cheaper and last longer than piston-driven machines. However, both kinds of machines may degrade due to overuse and poor cleaning. Pumps are also more complicated mechanically, and can add to prices of even simple models.

Some espresso machines make use of steam pressure instead of a pump in order to brew espresso. The disadvantage of this is that the boiler that produces steam also increases the temperature of water to boiling which can cause over-extraction. In addition the machines often have to restore their pressure between cups, which requires time and energy.

Many espresso machines utilize a vibration or rotary pump, which has a vibration model that uses a vibrating disc to create pressure, and an rotary model that pushes hot water through the grounds at high speed. Both machines produce great barista espresso coffee machine however rotary machines tend to be more stable, quieter and less likely to break.

The Boiler

The boiler is the component which heats the water to the ideal temperature to extract. The steam that is created reaches the portafilter, which is a container for espresso grounds. The steam is then channeled into the cup. During this process the steam causes enough pressure to push the grounds of the coffee through. This results in a crema on top of the espresso. This is one of the hallmarks of a good espresso.

There are three kinds of espresso machines, each having different types of pumps and the temperature of the brew. There are various ways to control the brew as well as the size of the cup that can be made by the machine.

The first espresso machines were steam-types. They used one boiler to create both steam and brew but the pressure they could generate was low – only two bars of atmospheric pressure at most. The coffee tasted bitter and burned. This is why Milanese makers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most commonly used espresso maker is a semi-automatic one that has an electric pump. When people think of espresso machines, they envision these machines. With a semi-automatic machine you have to grind the beans and then tamp them by hand, but the pump provides regulated water flow and pressure. This is an excellent solution that combines human control with mechanized reliability.

The Filter

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

A filter also improves flavor because it allows for a longer flowering phase. This lets the beans release their nuances, and also allows for better extraction.

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

This is where the magic happens, and it’s what makes espresso taste great. The grouphead (also called the brewhead) is where you put the portafilter – the thingy that you put the grounds of your coffee into while making espresso.

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

In recent years, espresso machine with frother (click the up coming article) machines powered by compressed air-pump have become increasingly popular. They make use of an air compressor to push hot water across the ground and are much more mobile than electric steam-driven espresso makers machines.