The Biggest Problem With Machine Espresso And How You Can Resolve It

How Does Machine Espresso Work?

The machine espresso uses precise pressure and filtering system that is awe-inspiring to make the coffee you love. But how exactly does it work?

Espresso is made by forcing hot water at high pressure through finely ground coffee. The process is similar to that of making drip coffee. However the pressure is the main difference.

The Head of the Group

The group head is the portafilter is inserted when you are making espresso. It disperses water in the portafilter, and regulates the pressure of the extraction. There are several different types of group heads, each with their own advantages and disadvantages. Some focus on temperature stability, whereas others on pre-infusion capabilities, and still others are designed to control the lever. There are some that include a mix of features, such as the E61 that is to be the most popular among baristas because of its ability to offer multiple perks in one package.

As you can see in the above image the group head is made up of numerous notches that you can place your portafilter and then twist it manually to secure it. There is also a gasket made of rubber that resides inside the notches and helps to create an airtight seal when you insert your portafilter into the machine. The notches permit an exact placement of the portafilter. This is crucial to ensure a consistent extraction.

The group head not only allows you to insert your portafilter easily but also maintains an even temperature. This is done by cycling hot water around the portafilter, and through the brew-basket, ensuring the temperature is always right for extraction. This is important, as just a few degrees could make the difference between a good and great espresso.

The Pump

In contrast to manual piston machines which use a lever to pressurize water, rotary espresso machines rely on motorized pumps to supply the nine atmospheric bars of pressure needed to extract espresso. This pressure is built up by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are generally less expensive and last for longer than piston-driven machines. However, both kinds of machines can deteriorate because of excessive use and poor cleaning. They also increase the complexity of mechanical systems which can result in the cost of even the simplest models.

Some espresso machines do away with the pump completely and instead utilize steam pressure to make espresso. The disadvantage of this is that the boiler that produces steam also increases the temperature of the water to the point of boiling and can result in over-extraction. They also have to constantly rebuild their pressure between cups. This requires energy and time.

A majority of espresso machines use the rotary or vibration pump, with a vibrating model using a vibrating disc to create the pressure, and the rotary model pushing hot water through the grounds under high speed. Both types of machines can make a great espresso, however the rotary models are quieter and more durable than vibration pumps.

The Boiler

The boiler is the component that heats the water to the ideal temperature to extract. The steam produced is then directed to the portafilter, which contains the espresso coffee grounds. It is then funneled into the cup. In this process, the steam creates pressure to push through the grounds of the coffee. This results in a crema on machines coffee top of the espresso. This is the hallmark of a good espresso.

There are three kinds of espresso makers, which differ in the type of pump they use and the degree of heat that the coffee is. There are also different ways that the brew may be controlled as well as the size of the cup that the machine is capable of making.

The first espresso machines were steam-based. They used one boiler to create both brew and steam, but the pressure they could produce was very low - just two bars of atmospheric pressure at the most. This led to the coffee tasting bitter and burnt. This is the reason Milanese makers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.

The most commonly used espresso maker is a semi-automatic machine with an electric pump. When people think of espresso machines, they envision these machines. If you have a semi-automatic machine you must grind the beans and then tamp them yourself but the pump controls the flow of water and pressure. This is a perfect solution that combines human control with mechanised reliability.

The Filter

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

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

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

This is where the magic happens, and it's what makes an espresso really taste good. The grouphead, also referred to as the brew head, is where the portafilter (the device you put the coffee ground into) is placed when making espresso.

In the steam-driven espresso machine hot water is heated in an airtight tank to produce steam, which then pushes the hot water through the grounds with high pressure. These kinds of machines tend to be less expensive and simpler to maintain than pump-driven models. However, they are not as efficient in their capacity to create the ideal brewing conditions, since they are only operating at 1-1.5 bars of pressure. The perfect shot requires 9-10 bars.

In recent times, espresso machines powered by a compressed air compressor have become increasingly popular. They use an air compressor to push hot water through the grounds and are much more portable than electric steam-driven machines.