How Does Machine Espresso Work?

The machine espresso uses precision pressure, and filtering technology that is amazing to make the coffee you love. How exactly does it work?

To make espresso, hot water is pushed under pressure through finely ground coffee. The process is similar to making drip coffee, however the main difference lies 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 in the portafilter, and then regulates the pressure during the extraction. There are many different kinds of group head, each with their particular advantages and disadvantages. Some are specifically designed for the stability of temperature while some are built to handle pre-infusion. Others are made to control the lever. Some have a combination of features, like the E61 one, which is the most popular choice among baristas because of its ability to offer multiple benefits in one package.

As you can see from the above photo, the group head is fitted with several notches. It is possible to place your portafilter inside these notches, and then twist the head to secure it. There is also a gasket of rubber that resides inside the notches to help create an airtight seal when you insert your portafilter into the machine. The notches on the head permit a precise positioning of the portafilter which is essential to ensure a consistent extraction.

The group head not only lets you to insert your portafilter easily however it also keeps a constant temperature. It does this by circulating hot water through the brew container and around the portafilter to ensure that it is always at the correct temperature for extraction. This is crucial, since even a small difference in temperature can be 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 differs from manual piston machines that use a lever. The pressure is created by pumping water through a heat exchanger and then through the ground coffee machines espresso.

Pumps are generally less expensive and last for longer than piston-driven machines. However, both types of machines can degrade due to excessive use and poor cleaning. Pumps are also more complex mechanically, which can increase prices of even simplest models.

Certain espresso machines utilize steam pressure instead of a pump for brewing espresso. The drawback is that the same boiler that produces steam also increases the temperature of the water to the point of boiling, which can lead to excessive extraction. The machines also need to constantly rebuild their pressure in between cups. This takes energy and time.

Many espresso machines make use of either a vibration or rotary pump. A vibration model employs an oscillating disk to create pressure, whereas the rotary model pushes hot water through the ground at a high speed. Both types of machine can make a great espresso, however the rotary pumps are quieter, and more durable than vibration pumps.

The Boiler

The boiler is the element that heats the water to the optimal temperature to extract. The steam that is produced reaches the portafilter which holds the ground italian espresso machines and is then pumped down into the cup. The steam generates enough pressure to push the coffee grounds through. This results in a crema on top of the espresso. This is a hallmark of a good espresso.

There are three kinds of espresso makers, which differ in the type of pump they use and the degree of heat that the brew is. There are different ways to control the brew and the size of the cup that can be made by the machine.

The earliest espresso machines were steam types. The first espresso machines were steam-type machines. This resulted in the coffee tasting bitter and burnt. This is why Milanese producers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most common espresso maker is a semi-automatic one with an electric pump. These are the things people think of when they think of an espresso maker. Semi-automatic machines require you to grind and tamp the beans yourself however the pump controls the flow of water and pressure. This is a great compromise between the human touch and the mechanised accuracy.

The Filter

Espresso machines typically have a filter that separates the grounds of coffee from hot water. The filter is also a crucial part of the temperature control system as it prevents the machine from overheating.

It also enhances flavor, as a filter lets you enjoy a longer bloom phase. This allows beans to let their nuances out and provides an opportunity for a better extraction.

However it is crucial to remember that even a top filter can result in a poor cup of coffee, because the quality of the beans and extraction are vital.

It's in this area that the magic occurs. This is the reason why espresso tastes so good. The grouphead (also known as the brewhead) is where you place the portafilter, the thingy that you use to put the coffee grounds in, when making espresso machine black friday.

Steam-driven espresso machines make use of hot water heated in an airtight container to make steam. The steam then moves hot water through the coffee grounds under high pressure. These types of machines are generally less expensive and easier to maintain than pumps-driven models. They are however limited in their ability for creating the ideal conditions for brewing, as they operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

In recent times, espresso machines powered by a compressed air compressor have become increasingly popular. They make use of an air compressor to push hot water through the ground and are much more mobile than steam-driven electric espresso machines.