Maisie Birdwood

How Does Machine Espresso Work?

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

uk espresso machine is made by forcing hot water under high pressure through finely ground coffee. The process is similar to that of making drip coffee. However the pressure is the primary difference.

The Group Head

As the name implies the group head is the place you place your portafilter while making espresso. It disperses the water into the portafilter, and controls the pressure of the extraction. There are various kinds of group heads, each with their unique advantages and drawbacks. Some are designed to provide stability of temperature while others are specifically designed to handle pre-infusion. Others are made to control the lever. Some come with a combination of both, like the E61. This is a popular choice among baristas since it provides multiple benefits in one package.

As you can see from the picture above the head of the group is equipped with several notches. You can place your portafilter into these notches and turn the head around to secure it. A gasket made of rubber is positioned inside the notches to help create a seal when you insert your portafilter. The notches on the head allow for an exact positioning of the portafilter which is necessary to ensure a consistent extraction.

Apart from allowing you easily insert your portafilter, the group head is also responsible to ensure that the temperature remains even. This is done by cycling hot water around the portafilter and through the brew-basket to ensure that the temperature is always at the right level to extract the coffee. It is important to remember that even a few degree difference can make the difference between a great and a great espresso.

The Pump

Unlike manual piston machines, which use a lever to pressurize water, Rotary espresso machines rely on motorized pumps that provide the nine atmospheric bars of pressure necessary for espresso extraction. This pressure builds up by removing tap water from a reservoir, and pumping it through a heat exchanger before being shot through the ground coffee inside the group head.

Pumps are typically less expensive and last for longer than piston-driven machines. However, both kinds of machines may degrade because of frequent use and poor cleaning. They also increase the complexity of mechanical systems and can lead to costly prices for even the simplest models.

Certain espresso machines do away with the pump entirely and use steam pressure 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 frequently have to rebuild their pressure between cups, which takes time and energy.

A majority of espresso machines utilize the rotary or vibration pump. A vibration model utilizes an oscillating disk to create pressure, while a Rotary model pushes hot coffee through the ground at a high speed. Both types of machines can produce an excellent espresso, but rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler will heat the water to the ideal temperature for extraction. The steam that is created will eventually reach the portafilter, which is a container for retro espresso maker grounds. It is then funneled into the cup. The steam generates enough pressure to push the grounds of the coffee through. This creates a foam on top of the espresso. This is the hallmark of a great espresso.

There are three different types of espresso machines, each with a different type of pump and the temperature of the brew. There are a variety of ways to control the brew as well as the size of the cup that can be made by the machine.

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

The most common espresso machine is a semiautomatic with an electric pump. When people think of professional espresso machine machines, they think of these machines. With a semi-automatic machine, you have to grind the beans and tamp them by hand, but the pump regulates the flow of water and pressure. This is a fantastic combination of human control and mechanized accuracy.

The Filter

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

A filter also improves flavor since it allows for a longer flowering phase. This allows the beans to release their flavor and also allows for better extraction.

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

It's here that the magic occurs. This is the reason why espresso tastes so delicious. The grouphead, sometimes called the brew head, is where the portafilter (the thing you put the coffee ground into) is placed when making espresso.

In a steam-driven discount espresso machines machine, hot water is heated in an airtight tank to produce steam, which then pushes the hot water through the grounds with high pressure. These machines are less expensive and are easier for the user to maintain than pumps-driven models. However, they are limited in their ability to produce the perfect brewing conditions since they operate at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bars.

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