9 Things Your Parents Taught You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso makes use of precise pressure and amazing filter technology to make the delicious coffee we enjoy. What exactly is it?

In order to make espresso hot water is pushed under pressure through finely ground coffee. The process is similar to making drip coffee, however the main difference lies in the pressure.

The Group Head

As the name suggests the group head is where you place your portafilter while making espresso. It is responsible for dispersing the water into the portafilter and then controlling the pressure of the extraction. There are many different types of group heads each with distinct advantages and drawbacks. Some are specifically designed for stability of temperature while others are designed to handle pre-infusion. Others are made to control the lever. Some include a mix of features, like the E61 that is the most popular choice among baristas for its ability to provide multiple benefits in a single package.

As you can see from the image above, the group head has a number of notches. It is possible to place your portafilter in these notches and then turn the head around to secure it. There is also a rubber gasket that is a part of the notches and helps to create a seal when you insert your portafilter into the machine. The notches on the head permit an exact location of the portafilter which is essential to ensure a consistent extraction.

In addition to allowing you easily connect your portafilter, the group head is responsible to ensure that the temperature remains even. It does this by circulating hot water through the brew basket and around the portafilter, ensuring that it's always at the right temperature for extraction. It is important to note that even a small differences can make the distinction between a good and excellent espresso.

The Pump

The motorized pumps used in espresso machines rotary provide nine atmospheric bar pressure that is required to extract espresso. This is different from manual piston machines which use a lever. This pressure is generated by pumping water through a heat exchanger and then through the ground coffee.

Pumps are typically cheaper and last longer than piston-driven machines. However, both types of machines can degrade due to overuse and inadequate cleaning. They also increase the complexity of mechanical systems that can lead to a high price tag on even the simplest models.

Some espresso machines eliminate the pump completely and instead employ steam pressure to create espresso. This can lead to over-extraction as the boiler that makes steam also warms the water to boil. Additionally, these machines frequently have to restore their pressure between cups, which takes time and energy.

Many espresso machines utilize an rotary or vibrating pump, with a vibration model using a vibrating disc to create pressure and an rotary model that pushes hot water through the grounds at high speed. Both machines produce great retro espresso maker, however rotary machines are more quiet, durable and less likely to fail.

The Boiler

The boiler is the element that heats water to an ideal temperature for extraction. The steam produced will eventually reach the portafilter, which holds the espresso grounds. It is then poured into the cup. The steam creates pressure to push through the coffee grounds. This results in a layer crema on top. This is one of the main characteristics of a good espresso.

There are three kinds of espresso makers. They differ in the kind of pump they use and the degree of heat that the brew is. There are also different ways in which the brew could be controlled, as well as the dimensions of the cup the machine is capable of making.

The first espresso machines were steam-types. They utilized one boiler to make both brew and steam, however the pressure they were able to create was minimal - two bars of atmospheric pressure at the most. This led to the coffee tasting burnt and bitter. This is the reason why Milanese makers Luigi Bezzerra and Desiderio Pavoni developed the modern espresso machine.

The most popular espresso maker is a semi-automatic device that has an electric pump. When people think of espresso machines, they think of these machines. With a semi-automatic espresso machine, you must grind the beans and tamp them yourself but the pump regulates the flow of water and pressure. This is a fantastic solution that combines human control with mechanised accuracy.

The Filter

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

Filters also aid in flavor because it allows for an extended flowering time. This allows the beans to let their nuances out and provides an opportunity to improve extraction.

However it is crucial to keep in mind that even a good filter could result in a bad cup of coffee, since the quality of the beans and extraction is still vital.

This is where the magic happens, it's the thing that makes an espresso really taste good. The grouphead, sometimes referred to as the brew head, is where the portafilter (the thing you put the ground coffee in) sits when you're making espresso.

In a steam-driven espresso 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 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 ideal conditions for brewing because they operate at 1-1.5 bars of pressure. While the perfect shot requires 9-10 bars.

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