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14 Cartoons On Machine Espresso That'll Brighten Your Day
How Does Machine Espresso Work?

Machine espresso makes use of precise pressure and incredible filter technology to produce the delicious coffee we enjoy. How 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 pressure is the main difference.

The Group Head

The name implies, the group head is where you put your portafilter in when brewing espresso. It is responsible for dispersing water into the portafilter and controlling the pressure of the resulting extraction. There are many different types of group heads each with its own advantages and drawbacks. Some focus on temperature stability, whereas others on pre-infusion capabilities, while others are designed to control the lever. Some have a combination, such as the E61. This is a preferred choice for baristas as it provides a variety of benefits in a single package.

As you can see in the photo above the head of the group is fitted with a variety of notches. You can place your portafilter in these notches, then twist the head to secure it. A rubber gasket is located inside the notches to help create a seal when you insert your portafilter. The notches allow for an exact placement of the portafilter. This is essential for an accurate extraction.

The group head not only lets the portafilter to be inserted easily however it also keeps the same temperature. This is accomplished by cycling hot water around the portafilter, and through the brew-basket, making sure the temperature is always right for extraction. It is important to realize that even a few degree deviation can make the difference between a good and a excellent espresso.

The Pump

The motorized pumps in rotary espresso machines supply the nine atmospheric bars of pressure required for espresso extraction. This is different from manually operated piston machines that employ a lever. The pressure is created by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are typically less expensive than piston-driven models, and they tend to last longer, although both types of machines can be damaged by excessive use and inadequate cleaning. They also make mechanically complex, which can result in costly prices for even the simplest models.


Certain espresso machines utilize steam pressure instead of a pump to make espresso. This could lead to over-extraction since the boiler that makes steam also causes the water to boil. In addition, these machines frequently have to rebuild their pressure between cups, which takes time and energy.

A large majority of espresso machines employ either a vibration or rotary pump. A vibration model employs a vibrating disk to generate pressure, whereas a rotary model pushes hot water through the ground at a fast speed. Both machines produce great espresso, but rotary machines are quieter, more durable and less likely to break.

coffeee.uk is the part which heats the water to the ideal temperature for extraction. The resultant steam then reaches the portafilter containing the ground espresso coffee and gets funnelled down into the cup. The steam generates enough pressure to push the grounds of coffee through. This creates a crema on the top of the espresso. This is a hallmark of a great espresso.

There are three kinds of espresso makers, which differ in the kind of pump they use and the degree of heat that the espresso is. There are a variety of ways to control the brew and the size of cup that can be produced by the machine.

The first espresso machines were steam-types. They used a single boiler to make both steam and brew however, the pressure they could create was minimal - two bars of atmospheric pressure at the most. This resulted in the coffee tasting burnt and bitter. This is why the Milanese makers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.

The most commonly used espresso machine is a semiautomatic that has an electric pump. These are the things people think of when they imagine an espresso machine. With 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 an excellent compromise between human touch and mechanized accuracy.

The Filter

Typically, espresso machines use a filter to separate out the grounds of the coffee as they go through the hot water. The filter is also a vital part of the machine's temperature control, as it prevents overheating.

It also enhances flavor, since a filter lets you enjoy a longer bloom phase. This lets the beans release their flavors, and improves extraction.

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

It's here that the magic happens. This is what makes espresso taste so delicious. The grouphead, sometimes referred to as the brew head, is where the portafilter (the thing you put the ground coffee into) is placed when you're making espresso.

In a steam-driven espresso machine hot water is heated in an airtight tank to create steam, which is then pushed through the grounds with high pressure. These types of machines are generally cheaper and easier to maintain than pumps-driven models. However, they are limited in their ability to produce the perfect brewing conditions because they operate at 1-1.5 bars of pressure. The perfect shot requires 9-10 bars.

In recent years, espresso machines driven by compressed air-pump have become increasingly popular. They make use of an air compressor to force hot water into the ground, and are more mobile than steam-driven electric espresso machines.