How Does Machine Espresso Work?

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

To make an espresso, hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee espresso machines however the main difference lies in the pressure.

The Head of the Group

As the name implies, the group head is the place you place your portafilter when making espresso. It disperses the water into the portafilter and controls the pressure of the extraction. There are numerous kinds of group heads, each with its own advantages and drawbacks. Some are focused on temperature stability, while others on pre-infusion capabilities, and still others are designed to control the lever. Some come with a combination of both, like the E61. This is a popular choice among baristas as it provides a variety of benefits in one package.

As you can see in the above photo the group head is made up of numerous notches that you can place your portafilter and twist it by hand to lock it in. There is also a rubber gasket that resides inside the notches and helps to create an airtight seal when you insert your portafilter into the machine. The notches on the head allow for a precise placement of the portafilter, which is essential for a consistent extraction.

The group head is not just able to allow you to place your portafilter easily however, it also keeps the same temperature. It does this by circulating hot water through the brew basket and around the portafilter to ensure that it is always at the correct temperature for extraction. This is vital, because even a small difference in temperature can make the difference between a good and great espresso.

The Pump

The motorized pumps used in espresso machines rotary provide nine atmospheric bar pressure required to extract espresso. This is different from manually operated piston machines that employ a lever. The pressure builds up by drawing tap water from a reservoir, and pumping it through a heat exchanger prior being shot through the ground coffee inside the group head.

Pumps are generally less expensive and last for longer than piston-driven machines. However, both types of machines are susceptible to degrading because of excessive use and insufficient cleaning. Pumps are also more complicated mechanically, which can increase the cost of even the simpler models.

Some espresso machines do away with the pump completely and instead utilize steam pressure to make espresso. This can result in over-extraction because the boiler that makes steam also causes the water to boil. The machines also need to constantly rebuild their pressure between cups. This takes energy and time.

Many buy espresso machines machines employ the rotary or vibration pump, with a vibrating model that uses a vibrating disc that generates the pressure, and an rotary model that pushes hot water through the grounds at high speed. Both machines can produce excellent espresso but rotary machines are more stable, quieter and less likely to break.

The Boiler

The boiler will heat the water to the perfect temperature for extraction. The resultant steam then reaches the portafilter, which contains the ground compact espresso machine coffee and is then funneled down into the cup. The steam creates enough pressure to push the coffee grounds 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 makers, which differ in the type of pump they employ and the degree of heat that the coffee is. There are also different ways in which the brew can be controlled and the dimensions of the cup the machine can produce.

The first espresso machines were steam-types. The first espresso and filter coffee machine machines were steam types. This resulted in the coffee tasting bitter and burnt. This is why Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.

The most well-known espresso maker is a semiautomatic machine with an electric pump. This is what people envision when they imagine an espresso machine. With a semi-automatic machine you have to grind the beans and then tamp them by hand. The pump regulates the flow of water and pressure. This is a perfect solution that combines human control with mechanised reliability.

The Filter

Espresso machines usually have a filter that separates the coffee grounds from the hot water. The filter is also an essential component of the machine's temp control, as it prevents overheating.

It also helps with flavor, since a filter lets you enjoy a longer bloom time. This allows beans to release their flavor and gives an opportunity for better extraction.

However, it is important to keep in mind that even a high-quality filter can produce a bad cup of coffee, since the quality of the beans and extraction is essential.

This is where the magic happens, and it's what makes espresso taste good. The grouphead, sometimes called the brewhead, is where the portafilter (the device you put the coffee ground into) is placed when making espresso.

In an espresso machine that is driven by steam, hot water is heated in an airtight container to produce steam, which then pushes the hot water through the grounds with high pressure. These kinds of machines are typically less expensive and simpler to maintain than pump-driven models. However, they are limited in their ability to create the perfect conditions for brewing, because they operate at 1-1.5 bars of pressure, while the perfect shot requires 9 bar espresso coffee machines for sale machine - Read Much more --10 bars.

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