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Where Will Machine Espresso 1 Year From Now?
How Does Machine Espresso Work?

Machine espresso employs precise pressure and mind-blowing filter technology to create the perfect cup of coffee. What exactly is it?

Espresso is produced by pushing hot water at high pressure through finely ground coffee. The process is similar to that of making drip coffee. However the pressure is the primary difference.

The Group Head


As the name implies the group head is where you place your portafilter while brewing espresso. It disperses water in the portafilter and regulates the pressure of the extraction. There are many different types of group heads each with their own advantages and disadvantages. Some are focused on temperature stability, whereas others on pre-infusion capabilities, while others are designed to control the lever. There are some that contain a variety of features, like the E61, which is considered the most popular choice among baristas due to its capacity to provide multiple benefits in one package.

As you can see in the above photo the group head is equipped with several notches. You place your portafilter in these notches and then turn the head around to secure it. There is also a rubber gasket which is located inside the notches and helps to create the 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 even extraction.

The group head is not just able to allow you to place your portafilter easily, but it also maintains the temperature at a constant level. This is done by cycling hot water around the portafilter, and through the brew-basket, making sure that the temperature is constant to extract the coffee. This is important because just a few degrees could make the difference between good and great espresso.

The Pump

In contrast to 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 to extract espresso. This pressure builds up by drawing tap water from a reservoir and pumping it through a heat exchanger prior to being shot through the ground coffee in the group head.

Pumps are typically less expensive than piston-driven models, and they tend to last longer, but both types of machines may become damaged due to excessive use and poor cleaning. They also make mechanically complex and can lead to a high price tag on even the simplest models.

Some espresso machines eliminate the pump entirely and use steam pressure to brew espresso. The drawback of this is that the same boiler that produces steam also increases the temperature of the water to the point of boiling which could lead to excessive extraction. These machines also have to constantly rebuild their pressure in between cups. This takes energy and time.

A majority of espresso machines use a vibration or rotary pump, with a vibrating model using a vibrating disc to create the pressure and an rotary model that pushes hot water through the grounds under high speed. Both machines can make great espresso, but rotary machines are more quiet, durable and less likely to break.

The Boiler

The boiler is the one that heats the water to the right temperature for extraction. The steam that is created is then directed to the portafilter, which is the container that holds the espresso coffee grounds. It is then poured into the cup. The steam generates enough pressure to push the grounds of the coffee through. This results in a layer of crema on top. This is one of the main characteristics of a good espresso.

There are three types of espresso makers. They differ in the type of pump they use and how hot the espresso is. There are different ways in which the brew could be controlled, as well as the size of the cup that the machine can produce.

www.coffeee.uk were steam type. They had one boiler to create both steam and brew, however the pressure they were able to produce was very low - just two bars of atmospheric pressure at most. This led to the coffee tasting burnt and bitter. The modern espresso machine was invented by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso machine is a semiautomatic one with an electric pump. When people think of espresso machines, they imagine these machines. Semi-automatic machines require you to grind and tamp the beans on your own while the pump controls the water flow and pressure. This is an excellent solution that combines human control with mechanized reliability.

The Filter

Typically, espresso machines employ a filter to separate out the grounds of coffee as they move through the hot water. The filter is also a vital component of the machine's temp control, since it stops overheating.

It also helps with flavor, as it lets you enjoy a longer bloom phase. This helps the beans let their nuances out and provides the chance for better extraction.

It is important to keep in mind that even the most efficient filter can produce a bad cup of coffee. The quality of the beans and the extraction, are still crucial.

This is where the magic happens, it's what makes an espresso really taste good. The grouphead (also known as the brewhead) is where you put the portafilter - the thingy used to place the coffee grounds into, when making espresso.

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

In recent years, espresso machines driven by compressed air-pump are becoming increasingly popular. They utilize an air compressor to push hot water through the grounds and are significantly more portable than electric steam-driven machines.

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