9 . What 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 coffee we love. How exactly does it work?

In order to make espresso, hot water is pushed under pressure through finely ground coffee. The process is similar to making drip coffee. However it is the pressure that makes the main difference.

The Group Head

The name implies the group head is where you put your portafilter in when brewing espresso. It disperses water in the portafilter, and regulates the pressure during the extraction. There are various kinds of group heads each with its particular advantages and drawbacks. Some are designed for the stability of temperature while some are designed to handle pre-infusion. Others are built to control the lever. There are also some that have a combination of features, like the E61 one, which is the most popular choice among baristas due to its ability to offer multiple perks in one package.

As you can see in the photo above, the group head has several notches to put your portafilter, then twist it with your hands to lock it in. There is also a gasket of rubber in the notches and helps to create an airtight seal after inserting your portafilter into the machine. The notches on the head permit an exact placement of the portafilter, which is necessary for an even extraction.

The group head not only allows you to place your portafilter easily but also maintains the same temperature. It does this by circulating hot water through the brew basket and around the portafilter to ensure that it's always at the correct temperature for extraction. It is important to note that even a tiny variation can mean the difference between a decent and a great espresso.

The Pump

Contrary to manual piston machines which rely on a lever to pressurize water, Rotary espresso maker machines rely on motorized pumps that provide the nine atmospheric bars of pressure required to extract espresso. The pressure is created by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are generally cheaper and last longer than piston-driven machines. However, both types of machines are susceptible to degrading due to overuse and poor cleaning. Pumps are also more complex mechanically, which could increase the price of even the simpler models.

Some espresso machines eliminate the pump entirely and use steam pressure to brew espresso. The drawback is that the boiler that produces steam also raises the temperature of water to boiling which can cause over-extraction. They also have to continuously rebuild their pressure between cups. This requires energy and time.

Many espresso machines utilize the rotary or vibration pump, with a vibration model using a rotating disc to create pressure, and the rotary model pushing hot water through the grounds under high speed. Both types of machines can produce an excellent espresso, however the rotary models are quieter and more durable than vibration pumps.

The Boiler

The boiler is the one that heats the water to a temperature that is ideal for extraction. The steam created will eventually reach the portafilter, which contains the espresso coffee grounds. It is then pumped into the cup. The steam causes enough pressure to push the grounds of the coffee through. This results in a whipped-up the top of the espresso. This is a sign of a good espresso.

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

The first espresso machines were steam-type. They utilized only one boiler to make both steam and brew, however the pressure they were able to create was minimal - two bars of atmospheric pressure, at most. The coffee tasted bitter and burned. The modern espresso machine was designed by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso machine uk machine is a semiautomatic model with an electric pump. These are the things people think of when they think of an espresso machine. With a semi-automatic machine, you have to grind the beans and then tamp them yourself but the pump provides regulated water flow and pressure. This is a perfect combination of human control and mechanized consistency.

The Filter

Espresso machines typically have a filter that separates the grounds of the coffee from the hot water. The filter is also an essential component of the machine's temp control, since it stops overheating.

A filter can also help with flavor, as it permits the beans to flower for a longer period of time. This allows beans to let their nuances out and provides an opportunity to improve extraction.

It is important to keep in mind that even the finest 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 happens. This is the reason why espresso tastes so good. The grouphead (also called the brewhead) is where you put the portafilter - the thingy that you put the grounds of your coffee into while making buy espresso machines.

Steam-driven espresso machines use hot water heated in an airtight container to make steam. The steam then pushes hot water through grounds of coffee at high pressure. These kinds of machines tend to be cheaper and easier to maintain than pumps-driven models. However, they are not as efficient in their ability to provide the perfect brewing conditions as they only operate at 1-1.5 bars of pressure. However, the perfect shot requires 9-10 bars.

In recent years, compressed-air-pump-driven espresso machines have been gaining popularity. They use an air-compressor to push hot water through the ground. They are also more mobile than steam-driven electric espresso machines.