How Does Machine Espresso Work?

The machine espresso makes use of precise pressure, as well as a filtering technology that is amazing to create the coffee you enjoy. But how exactly does it work?

Espresso is created by forcing hot water under high pressure through finely-ground coffee. The process is similar to making drip coffee but the key difference is in the pressure.

The Group Head

The name implies, the group head is where you put your portafilter in when making home espresso machine. It is responsible for dispersing the water into the portafilter and controlling the pressure of the resulting extraction. There are numerous kinds of group heads each with their own advantages and disadvantages. Some are designed for stability of temperature while others are specifically designed to handle pre-infusion. Some are designed to control the lever. There are even some that include a mix of features, like the E61 that is to be the most popular among baristas because of its ability to offer multiple perks in a single package.

As you can see in the picture above, the group head is equipped with several notches. The portafilter is placed inside these notches, and then twist the head to secure it. There is also a gasket of rubber in the notches and helps to create the seal when you insert your portafilter into the machine. The notches on the head allow for a precise placement of the portafilter, which is crucial for a consistent extraction.

In addition to allowing you to easily connect your portafilter, best bean to cup espresso Machine the group head is also responsible to ensure that the temperature remains even. This is accomplished by cycling hot water around the portafilter, and through the brew-basket, making sure that the temperature is constant to extract the coffee. This is crucial, since even a small difference in temperature can be the difference between a good and excellent espresso.

The Pump

Contrary to manual piston machines which use a lever to pressurize water, rotary espresso machines rely on motorized pumps to provide the nine atmospheric bars of pressure needed to extract espresso. The pressure is created by drawing tap water from a reservoir, and pumping it through a heat exchanger prior to it is shot through the ground coffee in the group head.

Pumps tend to be cheaper than piston-driven models, and they tend to last longer, best Bean To cup espresso machine but both types of machines can get damaged through overuse and lack of cleaning. Pumps are also more complicated mechanically, which could increase the cost of even simpler models.

Certain espresso machines eliminate the pump completely and use steam pressure to brew espresso. The drawback of this is that the same boiler that produces steam also raises the temperature of water to boiling which could lead to over-extraction. The machines also need to constantly rebuild their pressure in between cups. This requires energy and time.

Many espresso machines utilize an rotary or vibrating pump, with a vibrating model using a vibrating disc to create pressure, and rotating models that push hot water through the grounds under high speed. Both types of machine can make excellent espresso, however the rotary pumps are quieter, and more durable than vibration pumps.

The Boiler

The boiler is the component that heats water to an optimal temperature for extraction. The steam produced gets to the portafilter which is a container for espresso grounds. It is then pumped into the cup. The steam creates pressure that pushes through the grounds of the coffee. This creates a foam on top of the espresso. This is one of the main characteristics of a good espresso.

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

The earliest espresso machines were steam type. They employed only one boiler to make steam and brew, however the pressure they were able best Bean to cup espresso machine produce was very low - just two bars of atmospheric pressure at most. This resulted in the coffee tasting burnt and bitter. This is why the Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni developed the modern espresso machine.

The most well-known retro espresso maker machine is a semiautomatic one with an electric pump. When people think of travel espresso maker machines, they picture these machines. If you have a semi-automatic machine you must grind the beans and tamp them by hand. The pump regulates the flow of water and pressure. This is a fantastic combination of human control and mechanised consistency.

The Filter

Typically, espresso machines utilize filters to separate the grounds of the coffee as they go through the hot water. The filter is also a vital part of the temperature control system, as it keeps the machine from overheating.

A filter also helps with flavor as it allows for a longer flowering period. This allows beans to let their nuances out and provides an opportunity for a better extraction.

However it is crucial to remember that even a top filter could result in a bad cup of coffee, because the quality of the beans and extraction are vital.

This is where the magic happens. It's what makes an espresso really taste good. The grouphead (also called the brewhead) is where you put the portafilter, the thingy used to place the coffee grounds into, when making espresso.

Steam-driven espresso machines make use of hot water that is heated in an airtight vessel to create steam. The steam then pushes hot water through the grounds of coffee under high pressure. These kinds of machines are typically cheaper and easier to maintain than pump-driven models. They are however limited to create the perfect brewing conditions as they only operate with 1-1.5 bar of pressure. The ideal shot requires 9-10 bars.

In recent years, compressed air pump-driven espresso machines have become more popular. They use an air-compressor to push hot water through the ground and are much more mobile than electric steam-driven espresso machines.