How Does Machine Espresso Work?

The machine espresso makes use of precision pressure, and filter technology that is awe-inspiring 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 machines espresso. However, the pressure is the main difference.

The Head of the Group

The name implies the group head is where you place your portafilter when making espresso. It is responsible for dispersing water into the portafilter, and controlling the pressure of the extraction. There are numerous kinds of group heads each with distinct advantages and disadvantages. Some are designed for the stability of temperature while some are designed to handle pre-infusion. Some are designed to control the lever. Some include a mix of features, like the E61 one, which is to be the most popular 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 equipped with several notches. It is possible to place your portafilter in these notches and then twist the head to secure it. There is also a gasket of rubber in the notches to help create an airtight seal when you insert your portafilter into the machine. The notches allow for precise placement of the portafilter. This is crucial to ensure an efficient extraction.

The group head is not just able to allow you to place your portafilter easily but also maintains the same temperature. It does this by cycling hot water through the brew container and around the portafilter, ensuring that it's always at the correct temperature for extraction. It is important to realize that even a small differences can make the distinction between a good and excellent espresso.

The Pump

In contrast to manual piston machines that use a lever to pressurize water, Rotary espresso coffee machine for home machines rely on motorized pumps that provide the nine atmospheric bars of pressure required to extract espresso. The pressure is created by pumping water through a heat exchanger and then through the ground coffee.

Pumps tend to be more affordable and last longer than piston-driven machines. However, both types of machines are susceptible to degrading because of frequent use and poor cleaning. Pumps are also more complex mechanically, and can add to prices of even simplest models.

Some espresso coffee makers machines use steam pressure instead of a pump for brewing espresso. The downside is that the same boiler that produces steam also raises the temperature of the water to the point of boiling which can cause excessive extraction. They also have to continually rebuild their pressure between cups. This takes energy and time.

A majority of espresso machines use either a rotary or vibration pump, which is a vibration model using a vibrating disc to create the pressure, and the rotary model pushing hot water through the grounds under high speed. Both models are capable of producing excellent espresso, however the rotary pumps are quieter, and more durable than vibration pumps.

The Boiler

The boiler heats the water to the right temperature to extract. The resulting steam reaches the portafilter which holds the ground espresso coffee, and is then pumped down into the cup. During this process, the steam creates pressure and pushes through the coffee grounds. This creates a layer crema that is then poured over. This is one of the hallmarks of a great espresso machine with milk frother.

There are three kinds of espresso makers. They differ in the type of pump they use and the degree of heat that the coffee is. There are various ways that the brew can be controlled and the dimensions of the cup the machine can make.

The earliest espresso machines were steam type. The earliest espresso machines were steam-type machines. The coffee tasted bitter and burned. The modern espresso machine was created by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.

The most common espresso machine is a semiautomatic that has an electric espresso maker pump. When people think of espresso machines, they think of these machines. If you have a semi-automatic machine you must grind the beans and then tamp them yourself but the pump regulates the flow of water and pressure. This is an excellent compromise between human control and mechanized accuracy.

The Filter

Espresso machines typically have filters that separate the grounds of the coffee from the hot water. The filter is also a vital component of the machine's temp control, since it stops overheating.

A filter also helps with flavor, as it permits a longer flowering phase. This lets the beans release their flavors, and also allows for better extraction.

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

It's here that the magic takes place. This is what makes espresso taste so good. The grouphead (also called the brewhead) is where you place the portafilter - the thingy used to place the coffee grounds into, while making espresso.

In a steam-driven espresso machine hot water is heated in an airtight container to create steam. This is then pushed through the grounds at a high pressure. They are less expensive and easier to maintain than pumps-driven models. They are however limited to create the ideal conditions for brewing since they only 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 become more popular. They use an air-compressor to push hot water through the ground, and are more mobile than steam-driven electric espresso machines.