How Does Machine Espresso Work?

Machine espresso makes use of precise pressure and amazing filter technology to make the perfect cup of coffee. What exactly is it that makes it work?

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

The Head of the Group

As the name implies, the group head is where you put your portafilter in when making travel espresso maker. It disperses water into the portafilter and controls the pressure of the extraction. There are many different types of group heads each with its own advantages and disadvantages. Some are designed for the stability of temperature while some are specifically designed to handle pre-infusion. Others are built to control the lever. Some are a combination, such as the E61. This is a favorite among baristas since it provides multiple benefits in a single package.

As you can see in the photo above the group head is equipped with several notches. The portafilter is placed into these notches and twist the head to secure it. There is also a gasket made from rubber which is located inside the notches and helps to create the seal when you insert your portafilter into the machine. The notches on the head allow for an exact positioning of the portafilter which is vital to ensure an efficient extraction.

In addition to allowing you effortlessly insert your portafilter 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 realize that even a few degree deviation can make the difference between a good and great espresso.

The Pump

Motorized pumps in espresso machines that rotate provide the nine atmospheric bar pressure that is required to extract espresso. This is different from manual piston machines which use a lever. The pressure is built by pumping water through a heat-exchanger and then through the ground coffee.

Pumps tend to be less expensive and last for longer than piston-driven machines. However, both types of machines are susceptible to degrading because of frequent use and inadequate cleaning. Pumps are also more complicated mechanically, and can add to the cost of even the simple models.

Certain espresso machines eliminate the pump entirely and employ steam pressure to create espresso. This can result in over-extraction because the boiler that produces steam also causes the water to boil. They also have to continuously rebuild their pressure between cups. This takes energy and time.

Many espresso machines utilize a vibration or rotary pump, which is a vibration model that uses a vibrating disc that generates the pressure and the rotary model pushing hot water through the grounds under high speed. Both machines can make excellent espresso however rotary machines tend to be quieter, more durable and less likely to break.

The Boiler

The boiler is the component that heats water to an ideal temperature for extraction. The steam that is produced reaches the portafilter, which contains the ground espresso coffee, and is then funneled down into the cup. In this process, the steam creates pressure that pushes through the coffee grounds. This results in a whipped-up top of the espresso. This is a hallmark of a good espresso.

There are three types of espresso makers, which differ in the kind of pump they use and the degree of heat that the espresso is. There are various ways to control the brew and the size of cup that can be made by the machine.

The first espresso machines were steam-type. The first espresso machines were steam types. This resulted in the coffee tasting bitter and burnt. The modern espresso machine was designed by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso machine is a semiautomatic with an electric pump. When people think of espresso machines, they picture these machines. Semi-automatic machines require you to grind and tamp the beans yourself, but the pump regulates the flow of water and pressure. This is a fantastic combination of human control and mechanized reliability.

The Filter

Espresso machines typically use filters that separate the grounds of the coffee from the hot water. The filter is also a vital component of the temperature control system as it keeps the machine from overheating.

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

However, it is important to remember that even a top filter can result in a poor cup of coffee, because the quality of the beans and extraction is crucial.

It's here that the magic takes place. This is the reason why espresso coffee machines for sale tastes so delicious. The grouphead, often called the brew head, is the place where the portafilter (the thingy you put the best coffee espresso machine ground into) is placed when making espresso.

Steam-driven espresso machines use hot water that is heated inside an airtight container to make 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 perfect conditions for brewing since they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

In recent times, espresso machines home machines powered by compressed air-pump are becoming increasingly popular. They make use of an air compressor to force hot water through the ground and are more mobile than steam-driven electric espresso machines.