How Does Machine Espresso Work?

Machine commercial espresso machine utilizes precise pressure and mind-blowing filter technology to create the perfect cup of coffee. What exactly is it that makes it work?

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 key difference is in the pressure.

The Group Head

The group head is the portafilter is inserted when you are making espresso. It is responsible for dispersing water into the portafilter before controlling the pressure of the resulting extraction. There are a variety of group heads each with distinct advantages and drawbacks. Some focus on temperature stability, whereas others on pre-infusion capabilities, while others are designed to control the lever. Some come with a combination of both, such as the E61. This is a very popular choice for baristas as it provides a variety of advantages in one package.

As you can see in the above image the group head comes with several notches where you place your portafilter and twist it manually to lock it in. There is also a gasket made from rubber that is a part of the notches and helps to create an airtight seal after inserting your portafilter into the machine. The notches on the head permit an exact positioning of the portafilter which is essential for an efficient extraction.

In addition to allowing you to effortlessly insert your portafilter the group head is responsible to ensure that the temperature remains even. It does this by circulating hot water through the brew container and around the portafilter, ensuring that it is always at the correct temperature to extract. It is important to note that even a small deviation can make the difference between a great and a excellent espresso.

The Pump

The motorized pumps that are used in espresso machines that rotate provide the nine atmospheric bar pressure that is 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 tend to be less expensive and last longer than piston-driven machines. However, both types of machines can deteriorate because of excessive use and insufficient cleaning. They also make mechanically complex that can lead to the cost of even the most basic models.

Certain espresso machines can eliminate the pump completely and make use of steam pressure to make espresso. The downside is that the same boiler that produces steam also increases the temperature of water to the point of boiling, which can lead to excessive extraction. Additionally the machines often have to rebuild their pressure between cups, which takes time and energy.

Many espresso machines employ an rotary or vibrating pump, with a vibration model using a rotating disc to create pressure and an rotary model that pushes hot water through the grounds under high speed. Both types of machines can make excellent espresso, however Rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the part that heats water to an ideal temperature to extract. The resulting steam reaches the portafilter, which contains the ground espresso and is then funneled down into the cup. During this process, steam creates pressure and pushes through the coffee grounds. This creates a crema on the top of the espresso. This is a sign of a good espresso.

There are three kinds of espresso makers. They differ in the kind of pump they use and the degree of heat that the brew is. There are a variety of ways that the brew can be controlled as well as the dimensions of the cup the machine can produce.

The first espresso machines were steam-types. They used one boiler to create both steam and brew however, the pressure they could produce was not very high - two bars of atmospheric pressure at most. This resulted in the coffee tasting burnt and bitter. This is why the Milanese producers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most common espresso maker is a semi-automatic device with an electric pump. When people think of espresso machines, they picture these machines. Semi-automatic machines require you to grind and tamp the beans by yourself The pump, however, regulates the water flow and pressure. This is an excellent compromise between human touch and the mechanized quality.

The Filter

Typically, espresso machines utilize filters that separate the grounds of coffee when they pass through the hot water. The filter is also an important component of the temperature control system, because it stops the machine from overheating.

It also enhances flavor, since a filter allows for a longer bloom phase. This allows the beans to release their flavors and provides an opportunity for a better extraction.

However it is crucial to remember that even a great filter could result in a bad cup of coffee, as the quality of the beans and extraction is still important.

It's in this area that the magic happens. This is what makes espresso taste so good. The grouphead (also called the brewhead) is where you place the portafilter, which is the thingy which you put the coffee grounds into, when making espresso.

Steam-driven espresso machines espresso machines make use of hot water heated in an airtight vessel to create steam. The steam then pushes hot water into the grounds of coffee at high pressure. These types of machines are generally less expensive and easier to maintain than pumps-driven models. However, they are not as efficient in their ability to provide the perfect conditions for brewing, as they only operate at 1-1.5 bars of pressure. While 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 through the grounds and are much more portable than steam-driven electric machines.