How Does Machine Espresso Work?

The machine espresso is made using precise pressure, as well as a filter technology that is mind-blowing to make the coffee you love. How exactly does it work?

espresso coffee machine is made by pushing hot water under high pressure through finely-ground coffee. The process is similar to making drip coffee, however the main difference lies in the pressure.

The Head of the Group

The group head is the portafilter that you place in the espresso maker when making it. It is responsible for dispersing the water into the portafilter and controlling the pressure that results from the extraction. There are a variety of group heads, each with its own advantages and drawbacks. Some are focused on temperature stability, whereas others on pre-infusion capabilities, while others are designed to control the lever. There are also some that include a mix of features, such as the E61, which is to be the most popular among baristas for its ability to offer multiple benefits in a single package.

As you can see from the photo above, the group head is equipped with several notches. You place your portafilter inside these notches, and then twist the head to lock it. A gasket of rubber is situated inside the notches to help create a seal as you insert your portafilter. The notches permit precise placement of your portafilter. This is essential for an efficient extraction.

In addition to allowing you to easily place your portafilter in, the group head is also responsible for maintaining an even temperature. It does this by circulating hot water through the brew container and around the portafilter, making sure that it is always at the right temperature for extraction. This is important, as just a few degrees could make the difference between good and excellent espresso.

The Pump

Contrary to manual piston machines which use a lever to pressurize water, rotating espresso machines rely upon motorized pumps to provide the nine atmospheric bars of pressure needed to extract espresso. The pressure is built 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. However, both types of machines can become damaged due to excessive use and poor cleaning. They also create mechanical complexity which can result in the cost of even the simplest models.

Some Authentic Italian Espresso Maker with Magnet Valve machines use steam pressure instead of a pump for brewing espresso. The drawback of this is that the same boiler that produces steam also increases the temperature of the water to boiling which can cause over-extraction. They also have to constantly rebuild their pressure between cups. This takes energy and time.

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

The Boiler

The boiler is the part which heats the water to the optimal temperature for extraction. The steam that is produced reaches the portafilter that contains the ground espresso coffee and is then pumped down into the cup. During this process, steam causes pressure to push through the grounds of the coffee. This creates a layer crema that is then poured over. This is one of the main characteristics of a good espresso.

There are three types of espresso makers, which differ in the type of pump they use and how hot the espresso is. There are a variety of ways in which the brew could be controlled and the dimensions of the cup the machine can make.

The first espresso machines were steam-type. They employed one boiler to create both steam and brew however, the pressure they could generate was low - only two bars of atmospheric pressure maximum. The coffee tasted bitter and burnt. This is why Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.

The most common espresso machine is a semiautomatic that has an electric pump. When people think of espresso machines, they picture these machines. With a semi-automatic espresso machine, you must grind the beans and tamp them yourself but the pump is able to regulate the flow of water and pressure. This is a great compromise between human control and mechanised accuracy.

The Filter

Typically, espresso machines use filters that separate the grounds of coffee when they pass through the hot water. The filter is also a vital part of the temperature control system, because it stops the machine from overheating.

A filter also helps with flavor, as it permits an extended flowering time. This lets the beans release their nuances, and also allows for better extraction.

However it is crucial to keep in mind that even a great filter could result in a bad cup of coffee, because the quality of the beans and extraction are essential.

It's in this area that the magic occurs. This is the reason why espresso tastes so delicious. The grouphead, often called the brew head, is where the portafilter (the container you place the ground coffee into) sits when you're making espresso.

In a steam-driven PHILIPS Black Espresso Machine - 4 Specialty Coffees (Suggested Looking at) machine, hot water is heated in an airtight container to create steam. Steam is then pushed through the grounds under high pressure. These kinds of machines tend to be less expensive and easier to maintain than pumps-driven models. However, they are limited in their ability to provide the perfect brewing conditions since they operate at 1-1.5 bars of pressure. The perfect shot requires 9-10 bars.

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