How Does Machine Espresso Work?

Machine espresso employs precise pressure and amazing filter technology to make the perfect cup of coffee espresso machine. How does it work exactly?

To make an espresso hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee but the major difference is in the pressure.

The Group Head

The name implies the group head is where you place your portafilter while making espresso. It distributes water into the portafilter and regulates the pressure during the extraction. There are many different types of group heads each with their own advantages and drawbacks. Some are focused on temperature stability, some on pre-infusion options, and others are designed to control the lever. Some are a combination, such as the E61. This is a very popular choice for baristas due to the fact that it has multiple benefits in one package.

As you can see in the image above, the group head has numerous notches that you can place your portafilter and then twist it manually to secure it. There is also a gasket of rubber in the notches to help create an airtight seal after inserting your portafilter into the machine. The notches on the head allow for an exact placement of the portafilter, which is essential for a consistent extraction.

The group head does not just allow you to put in 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, ensuring the temperature is always right to extract the coffee. This is crucial, since just a few degrees could be the difference between a good and excellent espresso.

The Pump

In contrast to manual piston machines which rely on a lever that pressurize water, rotating espresso machines rely upon motorized pumps to provide the nine atmospheric bars of pressure necessary for espresso extraction. The pressure is created by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are generally cheaper and last longer than piston-driven machines. However, both kinds of machines can deteriorate due to overuse and poor cleaning. Pumps are also more complicated mechanically, and can add to the cost of even the simplest models.

Certain espresso machines do away with the pump entirely and utilize steam pressure to make espresso. This could lead to over-extraction since the dual boiler espresso machine that produces steam also heats the water until it comes to a boil. These machines also have to continuously rebuild their pressure between cups. This requires energy and time.

A large majority of espresso machines employ either a vibration or rotary pump. A vibration model employs the vibrating disk to create pressure, while the circular model pushes hot liquid through the ground at high speed. Both types of machine are capable of producing excellent espresso, but Rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the one that is used to heat the water to the right temperature to extract. The resulting steam is then transferred to the portafilter that contains the ground espresso and is then funneled down into the cup. During this process the steam generates enough pressure to push the coffee grounds through. This produces a layer of crema on top. This is a sign of a great espresso.

There are three types of espresso makers, and they differ in the type of pump they use and how hot the brew is. There are also different ways in which the brew could be controlled and the dimensions of the cup the maker can create.

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 makers Luigi Bezzerra and Desiderio Pavoni developed the modern espresso machine.

The most commonly used espresso maker is a semi-automatic one that has an electric pump. When people think of espresso machines, they think of these machines. With a semi-automatic espresso machine, you need to grind the beans and tamp them yourself but the pump is able to regulate the flow of water and pressure. This is an excellent solution that combines human control with mechanized accuracy.

The Filter

Typically, espresso machines utilize filters that separate the grounds of coffee when they pass through the hot water. The filter is also a vital part of the machine’s temperature control, as it prevents overheating.

It also enhances flavor, since a filter can allow for a longer bloom phase. This lets the beans let their nuances out, and allows for a better extraction.

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

This is where the magic happens. It’s what makes espresso taste good. The grouphead, sometimes referred to as the brew head, is the place where the portafilter (the thingy you put the ground coffee in) is placed when you’re making espresso.

In an espresso machine that is driven by steam, hot water is heated in an airtight tank to create steam. This is then pushed through the grounds at a high pressure. These types of machines are typically less expensive and simpler to maintain than pump-driven models. However, they are not as efficient in their ability to provide the perfect conditions for brewing, since they are only operating at 1-1.5 bars of pressure. The perfect shot requires 9-10 bar.

In recent years, compressed air-driven espresso machines have become more popular. They utilize an air compressor to force hot water into the ground, and are more mobile than electric steam-driven best budget espresso machine machines.