13 Things About Machine Espresso You May Not Know

How Does Machine Espresso Work?

The machine espresso uses precise pressure and filtering technology that is amazing to make the coffee you enjoy. How exactly does it work?

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

The Group Head

As the name suggests the group head is where you place your portafilter when brewing espresso. It disperses water into the portafilter, and then regulates the pressure of extraction. There are a variety of types of group head each with its own advantages and disadvantages. Some are specifically designed for stability of temperature while others are designed to handle pre-infusion. Others are made to control the lever. Some have a combination, like the E61. This is a popular choice among baristas since it provides multiple benefits in one package.

As you can see in the image above the group head is made up of several notches to put your portafilter, then twist it manually to lock it in. There is also a gasket of rubber in the notches and helps create an airtight seal after inserting your portafilter into the machine. The notches on the head permit a precise positioning of the portafilter which is essential for a consistent extraction.

Aside from allowing you to effortlessly insert your portafilter the group head is also responsible to maintain an even 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 important to remember that even a slight difference can make the difference between a good and great espresso.

The Pump

The motorized pumps in espresso machines that rotate provide the nine atmospheric bar pressure required to extract espresso. This differs from manual piston machines which use levers. The pressure builds up by drawing tap water from a reservoir and pumping it through a heat exchanger before being pumped through the ground coffee inside the group head.

Pumps are generally less expensive and last longer than piston-driven machines. However, both kinds of machines may degrade due to excessive use and insufficient cleaning. Pumps are also more complicated mechanically, which can increase the cost of even simplest models.

Certain espresso machines do away with the pump completely and make use of steam pressure to make espresso. This could lead to over-extraction since the boiler that produces steam also causes the water to boil. The machines also need to continually rebuild their pressure between cups. This takes energy and time.

A majority of espresso machines utilize a rotary or vibration pump. A vibration model makes use of the vibrating disk to create pressure, while the Rotary model pushes hot coffee through the ground at high end espresso machine speed. Both machines can produce 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 created will eventually reach the portafilter, which is the container that holds the compact espresso machine coffee grounds. It is then pumped into the cup. During this process, the steam causes pressure to push through the grounds of the coffee. This produces a layer of crema on top. This is a hallmark of a great espresso machine with frother.

There are three distinct types of espresso machines, each having distinct pumps and the temperature of the brew. There are many ways to control the brew as well as the size of the cup that can be produced by the machine.

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

The most well-known espresso maker is a semi-automatic one with an electric pump. These are the images people have when they think of an espresso machine. With a semi-automatic machine you grind the beans and then tamp them by hand. However, the pump is able to regulate the flow of water and pressure. This is an excellent combination of human control and mechanised consistency.

The Filter

Espresso machines typically have a filter that separates the grounds of coffee from hot water. The filter is also a vital element of the temperature control system because it stops the machine from overheating.

Filters also aid in flavor as it allows for the beans to flower for a longer period of time. This helps the beans release their flavor and gives an opportunity to improve extraction.

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

It's in this area that the magic occurs. This is what makes espresso taste so good. The grouphead, often called the brew head, is where the portafilter (the thing you put the ground coffee into) is placed when making espresso.

Steam-driven espresso machines make use of hot water heated in an airtight container to create steam. The steam then moves hot water through the grounds of coffee under high pressure. These machines are less expensive and easier to maintain than pumps-driven models. However, they are not as efficient in their capacity to create the ideal brewing conditions, since they operate at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bar.

In recent years, compact espresso machine machines powered by a compressed air compressor have become increasingly popular. They use an air-compressor to force hot water into the ground, and are more mobile than electric steam-driven espresso machines.