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It's The Ugly Reality About Machine Espresso
How Does espresso coffee machines ?

The machine espresso makes use of precision pressure, and a filter technology that is awe-inspiring to create the coffee you enjoy. How does it work exactly?

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 Head of the Group

The group head is the portafilter you insert when brewing espresso. It disperses water into the portafilter, and controls the pressure of the extraction. There are several different types of group head, each with their particular advantages and drawbacks. Some are designed to provide temperature stability while others are built to handle pre-infusion. Others are built to control the lever. Some include a combination such as the E61. This is a popular choice among baristas due to the fact that it has multiple advantages in one package.

As you can see in the image above, the group head has several notches where you place your portafilter before twisting it manually to lock it in. A rubber gasket is located in the notches to make a seal when you insert your portafilter. The notches permit precise placement of the portafilter. This is essential for an accurate extraction.

The group head not only lets you to insert your portafilter easily however it also keeps an even temperature. It does this by cycling hot water through the brew basket and around the portafilter, ensuring that it is always at the right temperature for extraction. This is crucial, since even a few degrees can mean the difference between excellent and great espresso.

The Pump

Contrary to manual piston machines that use a lever to pressurize water, rotating espresso machines rely upon motorized pumps that provide the nine atmospheric bars of pressure needed for espresso extraction. This pressure builds up by removing tap water from a reservoir, and pumping it through a heat exchanger prior to being shot through the ground coffee in the group head.

Pumps are generally less expensive than piston-driven models, and they tend to last longer, although both types of machines could become damaged due to excessive use and poor cleaning. They also make mechanically complex that can lead to costly prices for even the simplest models.

Certain espresso machines do away with the pump completely and instead use steam pressure to brew espresso. The drawback of this is that the boiler that produces steam also increases the temperature of the water to boiling and can result in excessive extraction. In addition these machines are often required to restore their pressure between cups, which requires time and energy.


A majority of espresso machines utilize either a vibration or rotary pump. A vibration model makes use of an oscillating disk to create pressure, while a rotating model pushes hot water through the ground at high speed. Both types of machine can make excellent espresso, but rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler will heat the water to a temperature that is ideal for extraction. The resulting steam is then transferred to the portafilter which holds ground espresso beans and is then pumped into the cup. The steam causes enough pressure to push the grounds of the coffee through. This produces a layer of crema that is then poured over. This is the hallmark of a good espresso.

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

The first espresso machines were steam-type. They had one boiler to create both brew and steam, 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 designed by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.

The most well-known espresso maker is a semiautomatic machine with an electric pump. These are the things people think of when they think of an espresso maker. Semi-automatic machines require you to grind and tamp the beans on your own, but the pump regulates the water flow and pressure. This is a fantastic solution that combines human control with mechanised reliability.

The Filter

Typically, espresso machines use filters to separate the grounds of coffee when they pass through the hot water. The filter is also a vital element of the temperature control system, since it helps prevent the machine from overheating.

It also helps with flavor, as a filter allows for a longer bloom time. This allows the beans to release their flavors and provides an opportunity for better extraction.

However it is crucial to remember that even a high-quality filter could result in a bad cup of coffee, since 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 (also known as the brewhead) is where you put the portafilter, which is the thingy used to place the grounds of your coffee 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 into the grounds of coffee under high pressure. They are less expensive and are easier for the user to maintain than pumps-driven models. However, they are not as efficient in their ability to provide the ideal brewing conditions, since they are only operating at 1-1.5 bars of pressure. The perfect shot requires 9-10 bars.

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

Read More: https://chang-spears.federatedjournals.com/10-no-fuss-methods-to-figuring-out-your-best-espresso-machine-1724293551