9 . What Your Parents Taught You About Machine Espresso

How Does Machine Espresso Work?

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

Espresso is made by pushing 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

As the name implies the group head is where you put your portafilter in when making espresso. It is responsible for dispersing water into the portafilter, and controlling the pressure of the resulting extraction. There are a variety of group heads each with its own advantages and drawbacks. Some are specifically designed for temperature stability while others are built to handle pre-infusion. Others are built to control the lever. There are even some that include a mix of features, such as the E61, which is considered the most popular choice among baristas because of its ability to offer multiple perks in a single package.

As you can see in the above image the group head comes with several notches to put your portafilter, then twist it manually to secure it. There is also a gasket made of rubber in the notches and helps create a seal when you insert your portafilter into the machine. The notches on the head permit a precise position of the portafilter which is vital for a consistent extraction.

The group head not only allows the portafilter to be inserted easily however it also keeps the temperature at a constant level. 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 to extract. It is important to note that even a small variation can mean the difference between a good and a great espresso.

The Pump

The motorized pumps used in espresso machines rotary provide nine atmospheric bars of pressure required to extract espresso. This differs from manual piston machines that rely on levers. The pressure builds up by drawing tap water from a reservoir and pumping it through a heat exchanger prior 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 can deteriorate due to overuse and insufficient cleaning. They also add mechanical complexity that can lead to an expensive price for even the most basic models.

Certain espresso machines utilize steam pressure instead of a pump in order to brew espresso. This could lead to over-extraction since the boiler that produces steam also causes the water to boil. In addition these machines are often required to rebuild their pressure between cups, which takes time and energy.

Many espresso machines use either a vibration or rotary pump. A vibration model employs a rotating disk to generate pressure, while a circular model pushes hot liquid through the ground at a rapid speed. Both machines can produce excellent espresso, but rotary machines are more stable, quieter and less likely to break.

The Boiler

The boiler is the part that heats water to the optimal temperature to extract. The resulting steam is then transferred to the portafilter, which contains the ground espresso and gets funnelled down into the cup. During this process, the steam creates pressure that pushes through the coffee grounds. This produces a layer of crema on top. This is a sign of a great espresso.

There are three kinds of espresso machines, each with a different type of pump and the temperature of the brew. There are different 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-types. The earliest espresso machines were steam-type machines. This led to the coffee tasting bitter and burnt. This is why Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni invented the modern professional espresso maker machine.

The most common espresso maker is a semi-automatic machine that has an electric espresso maker pump. When people think of espresso machines, they envision these machines. Semi-automatic machines require you to grind and tamp the beans by yourself The pump, however, regulates the flow of water and pressure. This is a great combination of human control and mechanised accuracy.

The Filter

Typically, espresso machines have filters that separate the coffee grounds as they pass through the hot water. The filter is also a vital element of the machine's temperature control, since it helps to prevent overheating.

A filter can also help with flavor because it allows for a longer flowering phase. This allows the beans to release their nuances, and improves extraction.

It is important to remember that even the best filter can result in a bad cup of coffee. The quality of the beans, as well as the extraction, are still crucial.

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 coffee grounds in, while making espresso.

In a steam-driven espresso machine hot water is heated in an airtight container to create steam. Steam is then pushed through the grounds at a high pressure. These machines are cheaper and are easier for the user to maintain than pumps-driven models. However, they are limited in their capacity to create the perfect conditions for brewing, as they only operate at 1-1.5 bars of pressure. While the perfect shot requires 9-10 bars.

In recent years, compressed air-driven uk espresso machine machines have become more popular. They use an air compressor to push hot water through the ground. They are also more mobile than electric steam-driven espresso machines.