How Does Machine Espresso Work?

Machine commercial espresso machine uses precision pressure and mind-blowing filter technology to create the best coffee espresso machine we love. How exactly does it work?

Espresso is made by forcing hot water at high pressure through finely ground coffee. The process is similar to making drip coffee but the key difference is in the pressure.

The Head of the Group

As the name suggests, the group head is the place you place your portafilter when brewing espresso. It is responsible for dispersing the water into the portafilter and then controlling the pressure of the resulting extraction. There are a variety of types of group heads each with its distinct advantages and disadvantages. Some are focused on temperature stability, some on pre-infusion features, and others are designed to control the lever. There are some that have a combination of features, such as the E61, which is considered the standard choice for many baristas due to its ability to provide multiple benefits in one package.

As you can see in the above image The group head features numerous notches that you can put your portafilter, then twist it by hand to lock it in. There is also a gasket made from rubber that resides inside the notches and helps to create a seal when you insert your portafilter into the machine. The notches on the head allow for an exact placement of the portafilter, which is crucial for a consistent extraction.

The group head does not just allow you to put in your portafilter easily however it also keeps an even temperature. This is achieved by cycling hot water around the portafilter and through the brew-basket, ensuring that the temperature is at the right level for extraction. This is important, as even a small difference in temperature can make the difference between a good and excellent espresso.

The Pump

In contrast to manual piston machines that use a lever to pressurize water, Machine espresso the rotary espresso machines use motorized pumps to provide the nine atmospheric bars of pressure that are required to extract espresso. This pressure is built up by pumping water through a heat-exchanger and then through the ground coffee.

Pumps tend to be less expensive than piston-driven machines, and they tend to last longer, however both types of machines can become damaged due to excessive use and poor cleaning. They also make mechanically complex that can lead to the cost of even the most basic models.

Certain espresso machines eliminate the pump completely and make use of steam pressure to make espresso. The downside is that the same boiler that produces steam also raises the temperature of the water until it reaches boiling which could lead to over-extraction. The machines must also continually rebuild their pressure between cups. This takes energy and time.

Many espresso machines make use of the rotary or vibration pump, which has a vibration model that uses a vibrating disc that generates the pressure and an rotary model that pushes hot water through the grounds at high speed. Both machines can produce excellent espresso but rotary machines are more stable, quieter and less likely to break down.

The Boiler

The boiler is the element that heats water to an ideal temperature for extraction. The steam that is produced reaches the portafilter containing the ground espresso coffee, and is then pumped down into the cup. During this process, the steam causes pressure to push through the coffee grounds. This results in 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 various ways to control the strength of the brew and the size of cup that can be made by the machine.

The first espresso machines were steam type. The first espresso machines were steam types. This resulted in the coffee tasting bitter and burnt. The modern espresso machine was developed by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

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

The Filter

Typically, espresso machines utilize filters that separate the grounds of coffee as they move through the hot water. The filter is also a crucial component of the temperature control system since it helps prevent the machine from overheating.

It also improves flavor, since a filter allows for a more prolonged bloom phase. This lets the beans let their nuances out, and improves extraction.

However it is crucial to remember that even a top filter can produce a bad cup of coffee as the quality of the beans and extraction are important.

This is where the magic happens, and it's what makes an espresso really taste good. The grouphead (also called the brewhead) is where you place the portafilter, the thingy which you put the grounds of your coffee into when making espresso.

In a steam-driven espresso machine, hot water is heated in an airtight tank to create steam. This is then pushed through the grounds with high pressure. These machines are less expensive and easier for the owner to maintain than pumps-driven models. They are however limited to create the perfect brewing conditions as they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

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