9 Things Your Parents Teach You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso utilizes precise pressure and mind-blowing filter technology to create the delicious coffee we enjoy. What exactly is it?

To make espresso hot water is forced under high pressure through finely best ground coffee for espresso machine coffee. The process is similar to making drip coffee, but the key difference is in the pressure.

The Head of the Group

The group head is the portafilter you place in the espresso maker when making it. It disperses water in the portafilter and regulates the pressure of the extraction. There are several different types of group heads, each with their particular advantages and drawbacks. Some are specifically designed for the stability of temperature while some are specifically designed to handle pre-infusion. Some are designed to control the lever. Some come with a range of features, like the E61, which is considered to be the most popular among baristas due to its ability to offer multiple perks in a single package.

As you can see from the above photo the group head is equipped with several notches. The portafilter is placed inside these notches, and then twist the head to lock it. There is also a gasket made of rubber in the notches to help create the seal when you insert your portafilter into the machine. The notches on the head permit an exact position of the portafilter which is crucial for an even extraction.

The group head not only lets the portafilter to be inserted easily however, it also keeps a constant temperature. It does this by cycling hot water through the brew pan and around the portafilter, making sure that it is always at the correct temperature for extraction. This is important because just a few degrees could mean the difference between excellent 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 provide the nine atmospheric bars of pressure required for espresso extraction. 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 in the group head.

Pumps are typically less expensive and last longer than piston-driven machines. However, both types of machines can degrade due to overuse and inadequate cleaning. Pumps are also more complicated mechanically, which can increase the cost of even simple models.

Some espresso machines employ steam pressure instead of a pump to make espresso. The disadvantage of this is that the boiler that produces steam also raises the temperature of the water until it reaches boiling which can cause excessive extraction. Additionally these machines are often required to restore their pressure between cups, which takes time and energy.

Many espresso machines use the rotary or vibration pump. A vibration model utilizes the vibrating disk to create pressure, whereas the Rotary model pushes hot coffee through the ground at a high speed. Both machines can make great espresso but rotary machines are more stable, quieter and less likely to break.

The Boiler

The boiler is the part that heats water to an ideal temperature for extraction. The steam that is created reaches the portafilter, which is the container that holds the espresso coffee grounds. The steam is then channeled into the cup. In this process, the steam creates pressure that pushes through the grounds of the coffee. This produces a layer of crema that is then poured over. This is a sign of a good espresso.

There are three types of espresso makers, and they differ in the type of pump they employ and the degree of heat that the coffee is. There are many ways to control the amount of brew, as well as the size of the cup that can be made by the machine.

The earliest espresso machines were steam types. They employed only one boiler to make steam and brew, however, the pressure they could generate was low - only two bars of atmospheric pressure, at most. The coffee tasted bitter and burnt. The modern espresso machine was developed by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso maker is a semi-automatic device with an electric pump. When people think of espresso machines, they imagine these machines. Semi-automatic machines require you to grind and tamp your beans yourself The pump, however, regulates the water flow and pressure. This is a fantastic combination of human control and mechanised reliability.

The Filter

Typically, espresso machines have filters to separate the grounds of the coffee as they go through the hot water. The filter is also a vital component of the machine's temp control, since it stops overheating.

A filter also helps with flavor, as it permits a longer flowering period. This helps the beans release their flavors and provides the chance for better extraction.

However it is crucial to keep in mind that even a top filter could result in a bad cup of coffee, since the quality of the beans and extraction is still vital.

This is where the magic happens, it's what makes espresso taste great. The grouphead (also known as the brewhead) is where you place the portafilter, the thingy that you use to put 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 create steam. The steam then pushes hot water through the coffee grounds under high pressure. These machines are cheaper and are easier for the user to maintain than pumps-driven models. However, they are not as efficient in their ability to provide the ideal brewing conditions, as they only operate at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bar.

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