A Vibrant Rant About Machine Espresso

How Does Machine Espresso Work?

The machine espresso makes use of precise pressure and filter technology that is mind-blowing to make the coffee you enjoy. But how exactly does it work?

Espresso is made by forcing hot water at high pressure through finely-ground coffee. The process is similar to that of making drip coffee. However, the pressure is the major difference.

The Group Head

The group head is the portafilter that you put in when making espresso. It disperses the water into the portafilter, and then regulates the pressure of extraction. There are several different types of group heads, each with their particular advantages and disadvantages. Some focus on temperature stability, while others on pre-infusion features, and others are designed to control the lever. There are some that include a mix of features, such as the E61 one, which is the most popular choice among baristas because of its ability to offer multiple perks in one package.

As you can see in the picture above the head of the group is fitted with a variety of notches. You can place your portafilter inside these notches, and then turn the head around to secure it. A gasket made of rubber is positioned inside the notches to help make a seal when you insert your portafilter. The notches on the head allow for an exact position of the portafilter which is vital to ensure an even extraction.

In addition to allowing you effortlessly insert your portafilter the group head is also responsible for maintaining an even temperature. This is achieved by cycling hot water around the portafilter, and through the brew basin, ensuring that the temperature is always at the right level for extraction. This is important, as even a small espresso machine difference in temperature can make the difference between good and excellent espresso.

The Pump

The motorized pumps in espresso machines that rotate provide the nine atmospheric bars of pressure required to extract espresso. This differs from manual piston machines that rely on a lever. This pressure is built up 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, however both types of machines could be damaged by excessive use and inadequate cleaning. Pumps are also more complicated mechanically, and can add to prices of even most basic models.

Certain espresso machines eliminate the pump entirely and employ steam pressure to create espresso. This can result in over-extraction because the boiler that makes steam also warms the water to boil. The machines also need to continuously rebuild their pressure between cups. This takes energy and time.

Many espresso machines use either a vibration or rotary pump. A vibration model employs a vibrating disk best bean to cup espresso machine generate pressure, while a circular model pushes hot liquid through the ground at high speed. Both types of machines 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 created will eventually reach the portafilter, which contains the espresso coffee machine espresso grounds. It is then funneled into the cup. The steam causes enough pressure to push the grounds of the coffee through. This creates a foam on top of the espresso. This is one of the hallmarks of a great espresso coffee makers.

There are three different types of espresso machines, each having distinct pumps and brew temperature. There are a variety of ways in which the brew can be controlled, as well as the size of the cup the machine is capable of making.

The first espresso machines were steam type. They utilized only one boiler to make steam and brew, however the pressure they were able to generate was low - only two bars of atmospheric pressure maximum. The coffee tasted bitter and burnt. The modern espresso machine was invented by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most popular espresso maker is a semi-automatic device that has an electric pump. When people think of espresso machines, they imagine these machines. With a semi-automatic machine, you must grind the beans and tamp them yourself but the pump is able to regulate the flow of water and pressure. This is an excellent compromise between human touch and the mechanized accuracy.

The Filter

best Espresso Machine under 500 machines usually have filters that separate the grounds of the coffee from the hot water. The filter is also a vital component of the temperature control system, because it stops the machine from overheating.

A filter can also help with flavor since it allows for a longer flowering period. This helps the beans release their nuances and gives an opportunity for better extraction.

It is important to remember that even the most efficient filter can result in a bad cup of coffee. The quality of the beans and the extraction process remain vital.

It's here that the magic takes place. This is what makes espresso taste so delicious. The grouphead, sometimes called the brewhead, is where the portafilter (the container you place the coffee grounds into) is placed when you're making espresso.

In an espresso machine that is driven by steam, hot water is heated in an airtight container to create steam. This then pushes the hot water through the grounds under high pressure. They are less expensive and are easier for the user to maintain than pumps-driven models. They are however limited in their ability for creating the ideal conditions for brewing as they only operate with 1-1.5 bar of pressure. The ideal shot requires 9-10 bars.

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