How Do I Explain Machine Espresso To A Five-Year-Old How Does Machine Espresso Work?

Machine espresso makes use of precise pressure and mind-blowing filter technology to make the coffee we love. What exactly does it work?

To make an 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

The group head is the portafilter you put in when making espresso. It is responsible for dispersing the water into the portafilter before controlling the pressure of the extraction. There are numerous kinds of group heads each with its own advantages and disadvantages. Some are specifically designed for the stability of temperature while some are built to handle pre-infusion. Some are designed to control the lever. Some include a combination like the E61. This is a popular choice among baristas since it provides multiple benefits in a single package.

As you can see in the photo above the group head is made up of many notches in which you can put your portafilter, then twist it manually to secure it. There is also a gasket made from rubber which is located inside the notches and helps to create an airtight seal when you insert your portafilter into the machine. The notches permit an exact placement of the portafilter. This is crucial for an even extraction.

The group head does not just allow you to place your portafilter easily, but it also maintains the same temperature. This is achieved by cycling hot water around the portafilter, and through the brew basin, ensuring that the temperature is always at the right level for extraction. This is crucial, since just a few degrees could be the difference between a good and excellent espresso.

The Pump

The motorized pumps in espresso machines rotary provide nine atmospheric bar pressure required for espresso extraction. This differs from manual piston machines which use a lever. This pressure builds up by removing tap water from a reservoir, and pumping it through a heat exchanger prior to being pumped through the ground coffee inside the group head.

Pumps tend to be less expensive than piston-driven machines, and tend to last longer. However, both types of machines could be damaged by excessive use and inadequate cleaning. They also add mechanical complexity that can lead to the cost of even the simplest models.

Some espresso machines use steam pressure instead of a pump to make espresso. The drawback of this is that the same boiler that produces steam also raises the temperature of the water until it reaches boiling and can result in excessive extraction. The machines must also constantly rebuild their pressure in between cups. This takes energy and time.

Many espresso machines make use of an rotary or a vibration pump. A vibration model makes use of the vibrating disk to create pressure, while the Rotary model pushes hot coffee through the ground at a rapid speed. Both types of machines can make a great espresso, however the rotary models are quieter and more durable than vibration pumps.

The Boiler


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

There are three distinct types of espresso machines, each with distinct pumps and the temperature of the brew. There are also different ways that the brew may be controlled, as well as the size of the cup that the machine can produce.

The earliest espresso machines were steam-based. They utilized only one boiler to make steam and brew, however, the pressure they could produce was very low - just two bars of atmospheric pressure at most. The coffee tasted bitter and burnt. The modern espresso machine was developed by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most well-known espresso maker is a semi-automatic device with an electric pump. When people think of espresso machines, they picture these machines. With a semi-automatic espresso machine, you must grind the beans and then tamp them by hand. The pump is able to regulate the flow of water and pressure. This is a fantastic combination of human control and mechanized reliability.

The Filter

Espresso machines typically use a filter that separates the coffee grounds from the hot water. The filter is also a vital part of the machine's temperature control, since it helps to prevent overheating.

It also improves flavor as a filter allows for a longer bloom phase. espresso coffee machine allows the beans to let their nuances out and provides an opportunity for better extraction.

However, it is important to remember that even a good filter can result in a poor 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 good. The grouphead (also called the brewhead) is where you put the portafilter, the thingy that you put the grounds of your coffee into while making espresso.

In the steam-driven espresso machine hot water is heated in an airtight container to create steam. Steam then pushes the hot water through the grounds with high pressure. These types of machines are typically less expensive and easier to maintain than pumps-driven models. They are however limited in their ability to create the ideal conditions for brewing since they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

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