How Does Machine Espresso Work?

The machine espresso machine with milk frother uses precision pressure, and filter technology that is awe-inspiring to make the coffee you enjoy. What exactly is it?

In order to make professional espresso machine For home, hot water is pushed under pressure through finely ground coffee. The process is similar to that of making drip coffee. However, the pressure is the primary difference.

The Head of the Group

As the name implies, the group head is the place you insert your portafilter when brewing espresso. It is responsible for dispersing the water into the portafilter and then controlling the pressure of the resulting extraction. There are various kinds of group head each with its distinct advantages and disadvantages. Some are specifically designed for stability in temperature, while others are built to handle pre-infusion. Others are made to control the lever. Some include a combination such as the E61. This is a preferred choice for baristas because it offers multiple benefits in a single package.

As you can see in the above photo the group head comes with numerous notches that you can put your portafilter, then twist it manually to secure it. A gasket made of rubber is positioned inside the notches to help create a seal when you insert your portafilter. The notches on the head allow for a precise location of the portafilter which is vital for an efficient extraction.

Aside from allowing you to easily insert your portafilter, the group head is also responsible for maintaining a consistent temperature. This is accomplished by cycling hot water around the portafilter, and through the brew-basket, ensuring the temperature is always right to extract the coffee. It is crucial to keep in mind that even a few degree deviation can make the difference between a decent and a excellent espresso.

The Pump

The motorized pumps used in espresso machines rotary provide nine atmospheric bar pressure needed to extract espresso. This is different from manually operated piston machines that employ a lever. This pressure is generated by pumping water through a heat-exchanger and then through the ground coffee.

Pumps tend to be cheaper than piston-driven models, and they tend to last longer, although both types of machine can become damaged due to excessive use and poor cleaning. They also make mechanically complex which can result in an expensive price for even the most basic models.

Some espresso machines do away with the pump entirely and utilize steam pressure to make espresso. The downside is that the same boiler that produces steam also increases the temperature of the water to the point of boiling which could lead to over-extraction. The machines must also continually rebuild their pressure between cups. This requires energy and time.

Many espresso machines make use of the rotary or vibration pump. A vibration model utilizes a rotating disk to generate pressure, while the Rotary model pushes hot coffee through the ground at a high speed. Both models can make excellent espresso, but the rotary models are quieter and more durable than vibration pumps.

The Boiler

The boiler is what makes the water warm to the ideal temperature for extraction. The steam created will eventually reach the portafilter, which is the container that holds the espresso coffee grounds. The steam is then channeled into the cup. During this process, the steam creates pressure to push through the coffee grounds. This produces a layer of crema that is then poured over. This is one of the hallmarks of a great espresso.

There are three distinct types of espresso machines, each with a different type of pump and brew temperature. There are a variety of ways to control the brew and the size of the cup that can be produced by the machine.

The first espresso machines were steam type. They utilized one boiler to make steam and brew, however, the pressure they could create was minimal - two bars of atmospheric pressure at most. This resulted in the coffee tasting burnt and bitter. This is the reason Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most popular espresso machine is a semiautomatic with an electric pump. These are what people imagine when they imagine an espresso machine. Semi-automatic machines require you bean to cup espresso machine grind and tamp the beans yourself The pump, however, regulates the flow of water 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 coffee grounds as they pass through the hot water. The filter is also an essential part of the temperature control system, because it stops the machine from overheating.

It also aids in flavor, since a filter lets you enjoy a longer bloom phase. This lets the beans release their nuances, and improves extraction.

It is important to remember that even the most efficient filter can result in a bad cup of coffee. The quality of the beans and the extraction process are still very important.

It's here that the magic occurs. This is what makes espresso taste so good. The grouphead (also called the brewhead) is where you put the portafilter, the thingy used to place the grounds of your coffee into when making espresso.

Steam-driven espresso machines make use of hot water that is heated in an airtight container to produce steam. The steam then pushes hot water through the coffee grounds under high pressure. These kinds of machines are usually less expensive and simpler to maintain than pumps-driven models. They are however limited to create the perfect brewing conditions as they only operate with 1-1.5 bar of pressure. The ideal shot requires 9-10 bars.

In recent years, compressed air-driven espresso machines have become more popular. They utilize an air compressor to push hot water across the best ground coffee for espresso machine and are much more mobile than steam-driven electric espresso machines.