How Does Machine Espresso Work?

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

Espresso 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 you place in the espresso maker when making it. It disperses the water into the portafilter, and regulates the pressure of extraction. There are numerous kinds of group heads each with its own advantages and disadvantages. Some are focused on temperature stability, others on pre-infusion capabilities, while others are designed to control the lever. Some come with a range of features, such as the E61 one, which is the standard choice for many baristas due to its ability to offer multiple perks in a single package.

As you can see in the photo above the group head comes with many notches in which you can place your portafilter before twisting it by hand to secure it. A gasket of rubber is situated inside the notches to help create a seal when you insert your portafilter. The notches on the head permit an exact position of the portafilter which is vital to ensure a consistent extraction.

The group head not only allows you to insert your portafilter easily, but it also maintains the same temperature. This is done by cycling hot water around the portafilter and through the brew-basket, making sure the temperature is always right to extract the coffee. This is important because just a few degrees could make the difference between a good and excellent espresso.

The Pump

Contrary to manual piston machines that use a lever to pressurize water, the rotary espresso machines use motorized pumps to deliver the nine atmospheric bars of pressure necessary to extract espresso. This pressure builds up by removing tap water from a reservoir and pumping it through a heat exchanger before being pushed through the ground coffee in the group head.

Pumps tend to be less expensive and last longer than piston-driven machines. However, both types of machines can degrade due to excessive use and insufficient cleaning. They also create mechanical complexity that can lead to costly prices for even the most basic models.

Some espresso machines employ steam pressure instead of a pump in order to brew espresso. The drawback of this is that the same boiler that produces steam also raises the temperature of water to boiling, which can lead to excessive extraction. The machines must also constantly rebuild their pressure in between cups. This takes energy and time.

A large majority of espresso machines employ the rotary or vibration pump. A vibration model makes use of a vibrating disk to generate pressure, while the Rotary model pushes hot coffee through the ground at high speed. Both machines can make great best home espresso machine but rotary machines are more quiet, durable and less likely to break.

The Boiler

The boiler is the one that will heat the water to the ideal temperature for extraction. The steam that is produced reaches the portafilter containing the ground espresso coffee, and is then funneled down into the cup. During this process the steam causes enough pressure to push the grounds of the coffee through. This creates a foam on the top espresso machines of the espresso. 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 how hot the brew is. There are various ways to control the amount of brew, as well as the size of the cup that can be produced by the machine.

The first espresso machines were steam type. The first espresso machines were steam types. The coffee tasted bitter and burnt. This is why Milanese makers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso coffee makers machine.

The most commonly used espresso maker is a semiautomatic machine with an electric pump. These are the images people have when they imagine an espresso machine. With a semi-automatic espresso machine (related webpage), you grind the beans and tamp them by hand. The pump controls the flow of water and pressure. This is a great solution that combines human control with mechanised reliability.

The Filter

Espresso machines typically have a filter that separates the grounds of the coffee from hot water. The filter is also an essential element of the temperature control system, as it keeps the machine from overheating.

It also improves flavor, since a filter can allow for a longer bloom phase. This allows the beans to release their flavors, and allows for a better extraction.

However it is crucial to keep in mind that even a good filter can produce a bad cup of coffee, as the quality of the beans and extraction are crucial.

It's in this area that the magic happens. This is the reason why espresso tastes so delicious. The grouphead (also called the brewhead) is where you place the portafilter, the device used to place the grounds of coffee into while making espresso.

Steam-driven espresso machines use hot water that is heated inside an airtight container to make steam. The steam then moves hot water through the grounds of the coffee under pressure. These kinds of machines are usually less expensive and easier to maintain than pumps-driven models. They are however limited in their ability for creating the ideal conditions for brewing, as they operate with 1-1.5 bar of pressure. The ideal shot requires 9-10 bars.

In recent times, espresso machines powered by a compressed air compressor have become increasingly popular. They use an air compressor to push hot water across the ground and are much more mobile than electric steam-driven espresso machines.