How Does Machine Espresso Work?

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

To make espresso, hot water is forced under high 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 place in the espresso maker when making it. It is responsible for dispersing the water into the portafilter before controlling the pressure of the resulting extraction. There are many different types of group heads each with distinct advantages and drawbacks. Some are designed for the stability of temperature while some are specifically designed to handle pre-infusion. Others are made to control the lever. There are also some that come with a range of features, such as the E61 one, which is to be the most popular among baristas due to its ability to provide multiple benefits in one package.

As you can see in the image above the group head is made up of several notches where you put your portafilter, then twist it by hand to secure it. A gasket made of rubber is placed within the notches to make a seal when you insert your portafilter. The notches permit precise placement of the portafilter. This is essential for an even extraction.

Apart from allowing you easily insert your portafilter, the group head is responsible for maintaining a consistent temperature. It does this by circulating hot water through the brew basket, and around the portafilter, ensuring that it is always at the correct temperature to extract. This is vital, because just a few degrees could make the difference between good and excellent espresso.

The Pump

Unlike manual piston machines, which rely on a lever that pressurize water, rotating espresso machines rely upon motorized pumps that provide the nine atmospheric bars of pressure necessary to extract espresso. The pressure builds by removing tap water from a reservoir, and pumping it through a heat exchanger prior to it is shot through the ground coffee inside the group head.

Pumps are generally less expensive and last longer than piston-driven machines. However, both types of machines may degrade due to overuse and insufficient cleaning. Pumps are also more complex mechanically, which can raise the cost of even the simplest models.

Some espresso machines do away with the pump completely and instead employ steam pressure to create espresso. The downside is that the boiler that produces steam also raises the temperature of the water to boiling and can result in over-extraction. Additionally these machines typically have to rebuild their pressure between cups, which requires time and energy.

A majority of espresso machines utilize a rotary or vibration pump. A vibration model employs an oscillating disk to create pressure, whereas the Rotary model pushes hot coffee through the ground at a high speed. Both machines can produce excellent espresso, but rotary machines are quieter, more durable and less likely to break down.

The Boiler

The boiler is what is used to heat the water to a temperature that is ideal to extract. The steam that is produced will eventually reach the portafilter, which contains the espresso coffee machine home coffee grounds. It is then pumped into the cup. The steam is able to create enough pressure to push the coffee grounds through. This creates a crema on top of the espresso. This is one of the hallmarks of a great espresso.

There are three kinds of espresso makers, which differ in the kind of pump they use and how hot the coffee is. There are different ways to control the brew and the size of the cup that can be produced by the machine.

The earliest espresso machines were steam types. The first espresso machine with frother machines were steam types. The coffee tasted bitter and burnt. The modern espresso machine was designed by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most well-known espresso maker [view website] is a semi-automatic device that has an electric pump. This is what people envision when they think of an espresso maker. Semi-automatic machines require you to grind and tamp the beans by yourself however the pump controls the water flow and pressure. This is an excellent compromise between human touch and mechanized quality.

The Filter

Typically, espresso machines have a filter to separate out the grounds of coffee when they pass through the hot water. The filter is also a crucial part of the temperature control system, as it keeps the machine from overheating.

It also enhances flavor as a filter can allow for a longer bloom phase. This allows the beans to release their flavor and also allows for better extraction.

It is important to remember that even the finest filter can make a bad cup of coffee. The quality espresso machine of the beans and the extraction process are still very important.

It's in this area that the magic happens. This is what makes espresso coffee machine home taste so good. The grouphead, often called the brewhead, is where the portafilter (the thing you put the ground coffee in) is placed when you're making espresso.

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 coffee grounds under high pressure. They are less expensive and easier for the owner to maintain than pumps-driven models. They are however limited in their ability to create the ideal conditions for brewing as they only operate with 1-1.5 bar of pressure. The ideal shot requires 9-10 bars.

In recent years, compressed air-pump-driven espresso machines have become more popular. They utilize an air compressor to push the hot water through the grounds and are more portable than steam-driven electric machines.