How Does Machine Espresso Work?

The machine espresso uses precise pressure, as well as a filtering system that is awe-inspiring to create the coffee you enjoy. What exactly is it?

Espresso is made by forcing hot water under pressure through finely ground coffee. The process is similar to making drip coffee but the major difference is in the pressure.

The Group Head

The group head is the portafilter that you insert when brewing espresso. It distributes water into the portafilter, and regulates the pressure during the extraction. There are various kinds of group head, each with their own advantages and drawbacks. Some are focused on temperature stability, while others on pre-infusion capabilities, while others are designed to control the lever. There are some that have a combination of features, like the E61, which is the most popular choice among baristas due to its capacity to provide multiple benefits in a single package.

As you can see in the photo above the group head is made up of numerous notches that you can place your portafilter and then twist it by hand to secure it. There is also a gasket made of rubber in the notches and helps to create a seal when you insert your portafilter into the machine. The notches allow for precise placement of your portafilter. This is essential for an efficient extraction.

Apart from allowing you easily place your portafilter in, the group head is responsible to ensure that the temperature remains even. It does this by circulating hot water through the brew pan and around the portafilter, ensuring that it is always at the right temperature for extraction. It is important to remember that even a slight differences can make the distinction between a great and a excellent cheap espresso machine.

The Pump

The motorized pumps that are used in espresso machines rotary provide nine atmospheric bar pressure that is required to extract espresso. This is different from manual piston machines that use levers. This pressure builds up by removing tap water from a reservoir and pumping it through a heat exchanger before being pushed through the ground coffee inside the group head.

Pumps are generally cheaper and last longer than piston-driven machines. However, both types of machines are susceptible to degrading due to excessive use and poor cleaning. They also increase the complexity of mechanical systems and can lead to an expensive price for even the most basic models.

Certain espresso machines eliminate the pump completely and instead utilize steam pressure to make espresso. The drawback is that the boiler that produces steam also raises the temperature of water to the point of boiling and can result in over-extraction. They also have to constantly rebuild their pressure between cups. This takes energy and time.

Many espresso machines use an rotary or a vibration pump. A vibration model employs a vibrating disk to generate pressure, whereas a circular model pushes hot liquid through the ground at a fast speed. Both models can produce an excellent professional espresso machine for home, however the rotary models are quieter and more durable than vibration pumps.

The Boiler

The boiler is the element that heats the water to the ideal temperature for extraction. The steam created gets to the portafilter which contains the espresso coffee grounds. It is then poured into the cup. During this process the steam causes enough pressure to push the grounds of coffee through. This results in a layer of crema that is then poured over. This is a hallmark of a good espresso.

There are three types of espresso makers. They differ in the kind of pump they use and how hot the espresso is. There are many ways to control the brew as well as the size of cup that can be made by the machine.

The first decent espresso machine machines were steam type. The earliest espresso machines were steam types. The coffee tasted bitter and burned. This is why the Milanese makers Luigi Bezzerra and Desiderio Pavoni developed the modern espresso machine.

The most well-known espresso machine is a semiautomatic model with an electric pump. When people think of espresso machines, they picture these machines. If you have a semi-automatic machine you need to grind the beans and then tamp them yourself but the pump regulates the flow of water and pressure. This is a great compromise between the human touch and the mechanized quality.

The Filter

Typically, espresso machines employ a filter to separate out the grounds of the coffee as they go through the hot water. The filter is also an essential element of the temperature control system, because it stops the machine from overheating.

It also improves flavor, as a filter allows for a more prolonged bloom time. This lets the beans release their flavor and also allows for better extraction.

It is important to remember that even the most efficient filter can make a bad cup of coffee. The quality of the beans and the extraction process, remain vital.

It’s in this area that the magic takes place. This is what makes espresso taste so good. The grouphead, often called the brewhead, is where the portafilter (the thingy you put the coffee ground into) sits when you’re making espresso maker.

Steam-driven espresso machines use hot water that is heated inside an airtight container to create steam. The steam then moves hot water through the grounds of coffee at high end espresso machine pressure. These types of machines tend to be less expensive and easier to maintain than pumps-driven models. However, they are not as efficient in their ability to produce the ideal brewing conditions, because they 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 become more popular. They use an air compressor to force hot water into the ground, and are more mobile than electric steam-driven espresso machines.