How To Explain Machine Espresso To Your Grandparents

How Does Machine Espresso Work?

The machine espresso is made using precision pressure, and filtering system that is awe-inspiring to create the coffee you love. How does it work exactly?

In order to make espresso hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee. However, the pressure is the major difference.

The Head of the Group

The group head is the portafilter that you put in when making espresso. It disperses water in the portafilter and regulates the pressure during the extraction. There are a variety of group heads, each with its own advantages and drawbacks. Some focus on temperature stability, some on pre-infusion capabilities, and still others are designed to control the lever. Some come with a combination of both, such as the E61. This is a popular choice among baristas since it provides multiple benefits in one package.

As you can see in the image above, the group head is equipped with several notches. You can place your portafilter inside these notches, and then turn the head around to secure it. A gasket made of rubber is positioned within the notches to create a seal as you insert your portafilter. The notches on the head allow for a precise position of the portafilter which is crucial to ensure an even extraction.

The group head does not just allow you to put in your portafilter easily however it also keeps a constant temperature. This is accomplished by cycling hot water around the portafilter and through the brew basin, ensuring the temperature is always right for extraction. This is vital, because even a few degrees can mean the difference between good and great espresso.

The Pump

The motorized pumps used in espresso machines that rotate provide the nine atmospheric bar pressure that is required for espresso extraction. This differs from manual piston machines that rely on a lever. The pressure builds by drawing tap water from a reservoir, and pumping it through a heat exchanger prior it is shot through the ground coffee inside the group head.

Pumps are generally less expensive 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 make mechanically complex and can lead to an expensive price for even the simplest models.

Some espresso machines do away with the pump completely and employ steam pressure to create espresso. The disadvantage of this is that the boiler that produces steam also raises the temperature of water to boiling which can cause excessive extraction. Additionally these machines are often required to restore their pressure between cups, which requires time and energy.

Many Mini Espresso Maker machines utilize either a rotary or vibration pump, with a vibrating model that uses a vibrating disc to generate the pressure and a rotary model pushing hot water through the grounds under high speed. Both machines produce great espresso capsule machine but rotary machines are more quiet, durable and less likely to break down.

The Boiler

The boiler is what will heat the water to the ideal temperature to extract. The steam created reaches the portafilter, which contains the espresso coffee grounds. It is then funneled into the cup. During this process, the steam causes pressure to push through the grounds of the coffee. This results in a layer of crema that is then poured over. This is one of the main characteristics of a great espresso.

There are three types of espresso makers. They differ in the type of pump they use and how hot the brew is. There are different ways to control the brew and the size of cup that can be produced by the machine.

The earliest espresso machines were steam-based. They had one boiler to make steam and brew, but the pressure they could generate was low - only two bars of atmospheric pressure maximum. This led to the coffee tasting burnt and bitter. The modern espresso machine was developed by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.

The most popular espresso maker is a semiautomatic machine with an electric pump. This is what people envision when they think of an espresso machine. With a semi-automatic machine, you have to grind the beans and tamp them by hand, but the pump provides regulated water flow and pressure. This is a great compromise between the human touch and the mechanised consistency.

The Filter

Espresso machines usually use a filter that separates the grounds of the coffee from the hot water. The filter is also an essential component of the machine's temperature control, since it stops overheating.

It also helps with flavor as a filter lets you enjoy a longer bloom phase. This allows the beans to release their nuances and gives an opportunity to improve extraction.

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

This is where the magic happens, and it's what makes an espresso really taste great. The grouphead, often called the brew head, is the place where the portafilter (the container you place the coffee ground into) is placed when making espresso.

In a steam-driven espresso machine hot water is heated in an airtight container to produce steam, which then pushes the hot water through the grounds at a high pressure. These kinds of machines tend to be cheaper and easier to maintain than pump-driven models. However, they are not as efficient in their capacity to create the perfect conditions for brewing, since they operate at 1-1.5 bars of pressure. The perfect shot requires 9-10 bars.

In recent years, compressed air-driven espresso machines have been gaining popularity. They use an air compressor to force the hot water through the grounds, and are far more portable than steam-driven electric machines.