Will Machine Espresso Always Rule The World? How Does Machine Espresso Work?

The machine espresso is made using precision pressure, and a filtering technology that is amazing to create the coffee you love. What exactly does it work?

In order to make espresso, hot water is pushed under pressure through finely ground coffee. The process is similar to that of making drip coffee. However, the pressure is the primary difference.

The Head of the Group


The name implies, the group head is the place you place your portafilter while brewing espresso. It distributes water into the portafilter, and regulates the pressure during 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 features, and others are designed to control the lever. There are even some that come with a range of features, like the E61, which is the most popular choice among baristas due to its ability to offer multiple benefits in a single package.

As you can see from the image above the group head is equipped with several notches. You can place your portafilter in these notches, then twist the head to lock it. There is also a rubber gasket that is a part of the notches and helps to create an airtight seal when you insert your portafilter into the machine. The notches on the head allow for an exact placement of the portafilter, which is necessary to ensure an even extraction.

In addition to allowing you effortlessly insert your portafilter the group head is responsible to ensure that the temperature remains even. This is done by cycling hot water around the portafilter, and through the brew-basket, ensuring that the temperature is constant for extraction. This is important, as just a few degrees could make the difference between a good and excellent espresso.

The Pump

The motorized pumps that are used in espresso machines rotary provide nine atmospheric bars of pressure required to extract espresso. This differs from manual piston machines that use levers. The pressure is created 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, although both types of machine can degrade with overuse and insufficient cleaning. Pumps are also more complex mechanically, and can add to the price of even the simpler models.

Some espresso machines use steam pressure instead of a pump in order to brew espresso. This can result in over-extraction because the boiler that makes steam also causes the water to boil. In addition these machines typically have to rebuild their pressure between cups, which requires time and energy.

Many espresso machines utilize either a rotary or vibration pump, with a vibration model using a vibrating disc to create the pressure, and an rotary model that pushes hot water through the grounds under high speed. Both types of machines are capable of producing excellent espresso, but 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 steam that is produced gets to the portafilter which holds the espresso grounds. The steam is then channeled into the cup. During this process, steam causes pressure to push through the coffee grounds. This results in a layer of crema on top. This is one of the hallmarks of a good espresso.

There are three kinds of espresso makers, which differ in the kind of pump they use and how hot the brew is. There are coffee machines espresso in which the brew could be controlled, as well as the size of the cup that the machine can produce.

The first espresso machines were steam-type. The earliest espresso machines were steam-type machines. This resulted in the coffee tasting bitter and burnt. This is why Milanese producers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most well-known espresso maker is a semiautomatic machine that has an electric pump. This is what people envision when they think of an espresso maker. Semi-automatic machines require you to grind and tamp the beans yourself while the pump controls the flow of water and pressure. This is a great compromise between the human touch and mechanized consistency.

The Filter

Typically, espresso machines use a filter to separate out the grounds of coffee when they pass through the hot water. The filter is also an essential element of the machine's temperature control, since it helps to prevent overheating.

A filter also improves flavor as it allows for a longer flowering phase. This allows beans to let their nuances out and provides an opportunity to improve extraction.

It is important to remember that even the most efficient filter can make a bad cup of coffee. The quality of the beans, as well as the extraction, are still crucial.

It's here that the magic occurs. This is the reason why espresso tastes so delicious. The grouphead, also called the brewhead, is where the portafilter (the device you put the coffee grounds into) sits when you're making espresso.

Steam-driven espresso machines use hot water heated in an airtight container to produce steam. The steam then pushes hot water into the grounds of coffee at high pressure. These machines are cheaper and easier for the user to maintain than pumps-driven models. However, they are limited in their capacity to create the ideal brewing conditions, because they operate at 1-1.5 bars of pressure. While the perfect shot requires 9-10 bar.

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