How Does Machine Espresso Work?

Machine espresso utilizes precise pressure and mind-blowing filter technology to create the perfect cup of coffee. What exactly is it that makes it work?

Espresso is made by pushing hot water under pressure through finely ground coffee. The process is similar to that of making drip coffee. However it is the pressure that makes the main difference.

The Head of the Group

The group head is the portafilter that you insert when brewing cheap espresso machine. It distributes water into the portafilter and regulates the pressure during the extraction. There are several different types of group heads each with its own advantages and drawbacks. Some are focused on temperature stability, some on pre-infusion options, and others are designed to control the lever. There are also some that have a combination of features, such as the E61, which is considered the standard choice for many baristas due to its capacity to offer multiple perks in a single package.

As you can see in the above image the group head is made up of many notches in which you can place your portafilter before twisting it by hand to secure it. There is also a rubber gasket which is located inside the notches and helps create an airtight seal when you insert your portafilter into the machine. The notches allow for precise placement of the portafilter. This is essential for an even extraction.

Apart from allowing you easily place your portafilter in, the group head is responsible to ensure that the temperature remains even. This is achieved by cycling hot water around the portafilter and through the brew-basket, ensuring that the temperature is always at the right level to extract the coffee. It is important to remember that even a slight differences can make the distinction between a great and a excellent espresso.

The Pump

The motorized pumps used in rotary espresso machines supply the nine atmospheric bar pressure needed to extract espresso. This differs from manually operated piston machines that employ a lever. The pressure is created by drawing 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 typically more affordable and last longer than piston-driven machines. However, both kinds of machines can deteriorate due to excessive use and poor cleaning. They also create mechanical complexity which can result in the cost of even the most basic models.

Some espresso machines do away with the pump completely and use steam pressure to brew espresso. The downside is that the boiler that produces steam also raises the temperature of water until it reaches boiling which could lead to excessive extraction. These machines also have to constantly rebuild their pressure between cups. This takes energy and time.

Many espresso machines utilize either a rotary or vibration pump, with a vibration model using a rotating disc to create the pressure, and a rotary model pushing hot water through the grounds at high speed. Both machines can produce excellent espresso, however rotary machines are more quiet, durable and less likely to break.

The Boiler

The boiler is the part which heats the water to the ideal temperature for Machine espresso extraction. The steam created will eventually reach the portafilter, which holds the espresso machine sale grounds. It is then pumped into the cup. The steam creates enough pressure to push the grounds of the coffee through. This creates a layer crema that is then poured over. This is the hallmark of a great espresso.

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

The first espresso machines were steam-types. They used only one boiler to make both steam and brew however the pressure they were able to produce was very low - just two bars of atmospheric pressure at the most. This resulted in the coffee tasting bitter and burnt. The modern espresso machine was created by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most common espresso maker is a semiautomatic machine with an electric pump. This is what people envision when they imagine an espresso machine. Semi-automatic machines require you to grind and Machine espresso tamp the beans by yourself The pump, however, regulates the water flow and pressure. This is an excellent compromise between human touch and the mechanized quality.

The Filter

Espresso machines typically have a filter that separates the coffee grounds from the hot water. The filter is also an important part of the temperature control system as it prevents the machine from overheating.

It also improves flavor, as a filter allows for a longer bloom time. This allows the beans to release their flavors, and also allows for better extraction.

It is important to remember that even the best filter could result in a poor 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 good. The grouphead, also referred to as the brew head, is the place where the portafilter (the thingy you put the ground coffee in) is placed when you're making espresso.

Steam-driven espresso machines use hot water heated in an airtight container to create steam. The steam then pushes hot water through the grounds of coffee under high pressure. These kinds of machines tend to be cheaper and easier to maintain than pump-driven models. However, they are limited in their ability to create the perfect brewing conditions as they only operate at 1-1.5 bars of pressure. However, the perfect shot requires 9-10 bars.

In recent years, compressed air pump-driven espresso machines have been gaining popularity. They use an air compressor to push hot water into the grounds and are much more portable than steam-driven electric machines.