How Does Machine Espresso Work?

Machine espresso employs precise pressure and mind-blowing filter technology to create the perfect cup of coffee. How does it work exactly?

Espresso is produced by pushing hot water under pressure through finely-ground coffee. The process is similar to making drip coffee, but the difference is in the pressure.

The Head of the Group

As the name suggests, the group head is the place you place your portafilter while making espresso. It is responsible for dispersing the water into the portafilter and controlling the pressure of the extraction. There are numerous kinds of group heads each with distinct advantages and drawbacks. Some are designed to provide stability in temperature, while others are specifically designed to handle pre-infusion. Others are built to control the lever. Some are a combination, such as the E61. This is a preferred choice for baristas due to the fact that it has multiple benefits in a single package.

As you can see in the photo above The group head features numerous notches that you can place your portafilter and twist it with your hands to secure it. There is also a gasket of rubber which is located inside the notches, which helps create the seal when you insert your portafilter into the machine. The notches on the head allow for an exact placement of the portafilter, which is essential for an efficient extraction.

Aside from allowing you to easily insert your portafilter, the group head is responsible for maintaining an even temperature. This is accomplished by cycling hot water around the portafilter, and through the brew-basket, making sure the temperature is always right for extraction. This is vital, because even a few degrees can mean the difference between excellent and great espresso coffee machine.

The Pump

In contrast to piston machines that are manually operated, which rely on a lever to pressurize water, rotary espresso machines rely on motorized pumps to deliver the nine atmospheric bars of pressure required for espresso extraction. This pressure is generated by pumping water through a heat-exchanger and then through the ground coffee.

Pumps tend to be cheaper than piston-driven machines and tend to last longer, but both types of machines could be damaged by excessive use and inadequate cleaning. Pumps are also more complicated mechanically, which can increase the cost of even simplest models.

Certain espresso machines can eliminate the pump entirely and use steam pressure to brew espresso. The disadvantage of this is that the same boiler that produces steam also raises the temperature of water to the point of boiling, which can lead to excessive extraction. Additionally these machines are often required to rebuild their pressure between cups, which requires time and energy.

Many espresso machines make use of a vibration or rotary pump, which is a vibration model that uses a vibrating disc that generates the pressure, and the rotary model pushing hot water through the grounds at high speed. Both machines produce great espresso, but rotary machines are more quiet, durable and less likely to fail.

The Boiler

The boiler is the part that heats water to the optimal temperature to extract. The resulting steam reaches the portafilter which holds the ground espresso coffee and is then funneled down into the cup. During this process, the steam creates pressure that pushes through the coffee grounds. This produces a layer of crema that is then poured over. This is one of the main characteristics of a good espresso.

There are three types of espresso makers. They differ in the kind of pump they use and the degree of heat that the espresso is. There are also different ways that the brew can be controlled and the dimensions of the cup the machine can make.

The earliest espresso machines were steam-based. The earliest espresso machines were steam types. This resulted in the coffee tasting bitter and burnt. The modern espresso machine was designed by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most popular espresso machine is a semiautomatic model with an electric pump. When people think of professional espresso machine machines espresso machines, they envision these machines. With a semi-automatic machine you need to grind the beans and tamp them by hand. However, the pump regulates the flow of water and pressure. This is a great compromise between the human touch and mechanized consistency.

The Filter

Typically, espresso machines utilize filters that separate the grounds of the coffee machine espresso as they go through the hot water. The filter is also an essential component of the temperature control system, as it prevents the machine from overheating.

It also enhances flavor, as it allows for a more prolonged bloom phase. This helps the beans let their nuances out and provides the chance for better extraction.

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

It's here that the magic takes place. This is what makes espresso taste so good. The grouphead, sometimes called the brewhead, is where the portafilter (the thing you put the ground coffee into) is located when you're making espresso.

Steam-driven espresso machines use hot water that is heated inside an airtight vessel to create steam. The steam then pushes hot water through grounds of coffee under high pressure. They are less expensive and easier for the user 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 bar espresso machine-10 bars.

In recent years, espresso machines powered by compressed air-pump are becoming increasingly popular. They use an air compressor to force hot water through grounds and are much more portable than steam-driven electric machines.