10 Machine Espresso-Related Meetups You Should Attend

How Does Machine Espresso Work?

Machine espresso maker barista utilizes precise pressure and mind-blowing filter technology to make the perfect cup of coffee. What exactly does it work?

Espresso is created by forcing hot water at high pressure through finely best ground coffee for espresso machine coffee. The process is similar to making drip coffee, but the difference is in the pressure.

The Head of the Group

The group head is the portafilter you put in when making espresso home machine. It disperses water in the portafilter, and controls the pressure of the extraction. There are several different types of group heads each with its unique advantages and disadvantages. Some focus on temperature stability, others on pre-infusion features, and others are designed to control the lever. Some come with a combination of both, such as the E61. This is a favorite among baristas as it provides a variety of benefits in a single package.

As you can see from the image above, the group head has a number of notches. It is possible to place your portafilter in these notches and then twist the head to lock it. There is also a gasket made from rubber which is located inside the notches and helps create a seal when you insert your portafilter into the machine. The notches on the head permit a precise position of the portafilter which is essential to ensure an even extraction.

The group head does not just allow you to insert your portafilter easily, but it also maintains the temperature at a constant level. This is accomplished by cycling hot water around the portafilter, and through the brew-basket, making sure that the temperature is constant for extraction. This is vital, because even a few degrees can be the difference between a good and great espresso.

The Pump

The motorized pumps in rotary espresso machines provide the nine atmospheric bar pressure required to extract espresso. This differs from manual piston machines that use levers. This pressure is built up by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are generally more affordable and last longer than piston-driven machines. However, both types of machines are susceptible to degrading because of excessive use and insufficient cleaning. They also add mechanical complexity and can lead to an expensive price for even the most basic models.

Some espresso machines use steam pressure instead of a pump to brew espresso. This can cause over-extraction because the boiler that makes steam also heats the water to boil. The machines also need to continually rebuild their pressure between cups. This requires energy and time.

A majority of espresso machines use a vibration or rotary pump, with a vibrating model using a rotating disc to create pressure, and rotating models that push hot water through the grounds under high speed. Both types of machine are capable of producing excellent espresso, however Rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the element that heats the water to the ideal temperature for extraction. The resulting steam is then transferred to the portafilter, which contains the ground espresso and gets funnelled down into the cup. During this process the steam generates enough pressure to push the grounds of the coffee through. This results in a whipped-up the top of the espresso. This is a sign of a good espresso.

There are three types of espresso machines, each with a different type of pump and the temperature of the brew. There are a variety of ways to control the strength of the brew and the size of the cup that can be made by the machine.

The first espresso machines were steam type. The earliest espresso machines were steam-type machines. This led to the coffee tasting burnt and bitter. This is why Milanese makers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most commonly used espresso machine is a semiautomatic with an electric pump. These are the things people think of when they think of an espresso machine. With a semi-automatic machine, you need to grind the beans and tamp them yourself but the pump regulates the flow of water and pressure. This is a great compromise between the human touch and the mechanised accuracy.

The Filter

Typically, espresso machines use filters that separate the grounds of coffee when they pass through the hot water. The filter is also an essential element of the temperature control system, since it helps prevent the machine from overheating.

It also enhances flavor, as a filter allows for a longer bloom time. This allows beans to let their nuances out and provides an opportunity to improve extraction.

It is important to remember that even the finest filter could result in a poor cup of coffee. The quality of the beans, and the extraction process are still crucial.

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

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

In recent years, compressed air pump-driven espresso machines have been gaining popularity. They use an air-compressor to force hot water into the ground, and are more mobile than steam-driven electric espresso machines.