9 Things Your Parents Taught You About Machine Espresso

How Does Machine Espresso Work?

machine espresso; idea.informer.com website, makes use of precise pressure and mind-blowing filter technology to create the perfect cup of coffee. How exactly does it work?

To make buy espresso makers hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee but the major difference is in the pressure.

The Head of the Group

The group head is the portafilter you insert when brewing espresso. It disperses water in the portafilter, and then regulates the pressure of extraction. There are a variety of group heads each with distinct advantages and drawbacks. Some focus on temperature stability, whereas others on pre-infusion features, and others are designed to control the lever. There are some that come with a range of features, such as the E61, which is considered the standard choice for many baristas due to its capacity to offer multiple perks in one package.

As you can see in the above image The group head features numerous notches that you can put your portafilter, then twist it with your hands to lock it in. There is also a gasket of rubber which is located inside the notches to help create an airtight seal after inserting your portafilter into the machine. The notches on the head permit an exact positioning of the portafilter which is vital to ensure an efficient extraction.

The group head does not just allow the portafilter to be inserted easily however it also keeps an even temperature. It does this by circulating hot water through the brew basket and around the portafilter, making sure that it's always at the right temperature for extraction. It is crucial to keep in mind that even a tiny variation can mean the difference between a good and a excellent espresso.

The Pump

Contrary to manual piston machines that use a lever to pressurize water, rotating espresso machines rely upon motorized pumps to deliver the nine atmospheric bars of pressure required for espresso extraction. The pressure is created 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 generally less expensive than piston-driven machines, and they tend to last longer, but both types of machine can get damaged through overuse and lack of cleaning. Pumps are also more complicated mechanically, which can raise the cost of even simplest models.

Certain espresso machines eliminate the pump completely and instead employ steam pressure to create espresso. This can lead to over-extraction as the boiler that makes steam also causes the water to boil. They also have to continuously rebuild their pressure between cups. This requires energy and time.

Many espresso machines employ the rotary or vibration pump, which is a vibration model using a rotating disc bean to cup espresso machines create the pressure and a rotary model pushing hot water through the grounds under high speed. Both machines can make great espresso however rotary machines tend to be more quiet, durable and less likely to break.

The Boiler

The boiler is the component which heats the water to the optimal temperature for extraction. The steam that is produced will eventually reach the portafilter, which contains the espresso coffee grounds. The steam is then channeled into the cup. The steam creates enough pressure to push the grounds of the coffee through. This creates a foam on top of the espresso. This is one of the main characteristics of a good espresso.

There are three different types of espresso machines, each having a different type of pump and the temperature of the brew. There are various ways to control the strength of the brew and the size of cup that can be made by the machine.

The first espresso machines were steam-type. They used one boiler to create both steam and brew however, the pressure they could produce was very low - just two bars of atmospheric pressure, at most. The coffee tasted bitter and burned. The modern espresso machine was created by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso machine is a semiautomatic one with an electric pump. When people think of espresso machines, they envision these machines. Semi-automatic machines require you to grind and tamp your beans yourself however the pump controls the water flow and pressure. This is a fantastic compromise between human control and mechanised reliability.

The Filter

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

It also helps with flavor, since a filter allows for a more prolonged bloom time. This lets the beans let their nuances out, and also allows for better extraction.

However, it is important to keep in mind that even a high-quality filter could result in a bad cup of coffee, because the quality of the beans and extraction is still vital.

This is where the magic happens, it's what makes espresso taste good. The grouphead (also called the brewhead) is where you put the portafilter, the thingy which you put the coffee grounds into, when making espresso.

Steam-driven espresso machines use hot water that is heated in an airtight vessel to create steam. The steam then moves hot water through the grounds of coffee under high pressure. These machines are cheaper and easier to maintain than pumps-driven models. They are however limited to create the perfect conditions for brewing as they only operate with 1-1.5 bar of pressure. The ideal shot requires 9-10 bars.

In recent times, espresso machines powered by compressed air-pump have become increasingly popular. They utilize an air compressor to force hot water through the grounds and are significantly more portable than steam-driven electric espresso maker machines.