9 Lessons Your Parents Taught You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso uses precision pressure and incredible filter technology to produce the delicious coffee we enjoy. How does it work exactly?

To make an espresso, hot water is pushed under pressure through finely ground coffee. The process is similar to that of making drip coffee. However, the pressure is the primary difference.

The Head of the Group

As the name implies the group head is the place you insert your portafilter when brewing italian espresso machine. It distributes water into the portafilter and regulates the pressure during the extraction. There are a variety of types of group heads each with its unique advantages and drawbacks. Some are specifically designed for temperature stability while others are built to handle pre-infusion. Others are made to control the lever. Some have a combination, such as the E61. This is a favorite among baristas due to the fact that it has multiple benefits in one package.

As you can see in the above image the group head comes with several notches to put your portafilter, then twist it by hand to secure it. There is also a gasket of rubber in the notches and helps create the seal when you insert your portafilter into the machine. The notches on the head allow for a precise location of the portafilter which is essential to ensure a consistent extraction.

The group head is not just able to allow the portafilter to be inserted easily however it also keeps an even temperature. It does this by cycling hot water through the brew container and around the portafilter to ensure that it's always at the right temperature for extraction. This is important, as just a few degrees could make 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 which use a lever. This pressure is generated by pumping water through a heat exchanger and then through the ground coffee.

Pumps are typically less expensive and last for longer than piston-driven machines. However, both kinds of machines can deteriorate because of excessive use and inadequate cleaning. They also increase the complexity of mechanical systems, which can result in costly prices for even the simplest models.

Some espresso machines use steam pressure instead of a pump to make espresso. This can lead to over-extraction as the boiler that makes steam also heats the water to boil. These machines also have to constantly rebuild their pressure in between cups. This takes energy and time.

Many espresso machines make use of an rotary or vibrating pump, which is a vibration model using a rotating disc to generate the pressure, and rotating models that push hot water through the grounds at high speed. Both types of machine can make excellent espresso, but the rotary models are quieter and more durable than vibration pumps.

The Boiler

The boiler is the element that heats water to the ideal temperature to extract. The steam that is produced will eventually reach the portafilter, which holds the espresso grounds. It is then poured into the cup. During this process, steam creates pressure that pushes through the grounds of the coffee. This results in a layer of crema on top. This is a sign of a great espresso.

There are three kinds of espresso makers, which differ in the type of pump they use and the degree of heat that the coffee is. There are a variety of ways in which the brew can be controlled, as well as the size of the cup the machine is capable of making.

The earliest espresso machines were steam-based. They employed one boiler to create both brew and steam, however the pressure they were able to produce was very low - just two bars of atmospheric pressure, at most. This led to the coffee tasting bitter and burnt. The modern espresso machine was invented by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso machine is a semiautomatic that has an electric pump. When people think of espresso machines, they imagine these machines. Semi-automatic machines require you to grind and tamp the beans on your own, but the pump regulates the flow of water and pressure. This is a great compromise between the human touch and the mechanised consistency.

The Filter

Espresso machines usually have a filter that separates the grounds of coffee from hot water. The filter is also an important part of the temperature control system, since it helps prevent the machine from overheating.

Filters also aid in flavor since it allows for a longer flowering phase. This helps the beans release their flavors and provides an opportunity for a better extraction.

It is important to remember that even the best bean to cup espresso machine filter can result in a bad cup of coffee. The quality of the beans as well as the extraction, remain vital.

This is where the magic happens. It's what makes an espresso really taste great. The grouphead (also called the brewhead) is where you put the portafilter, which is the thingy which you put the coffee grounds into, while making travel espresso maker.

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

In recent years, compressed air pump-driven espresso machines have been gaining popularity. They utilize an air compressor to push hot water through the ground and are more mobile than electric steam-driven espresso machines.