How Does machine espresso -
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Machine espresso utilizes precise pressure and amazing filter technology to make the coffee we love. How exactly does it work?
To make an espresso 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 Group Head
The group head is the portafilter that you put in when making
best home espresso machine. It disperses water in the portafilter and controls the pressure of the extraction. There are many different types of group heads each with their own advantages and drawbacks. Some are focused on temperature stability, while others on pre-infusion features, and others are designed to control the lever. Some come with a combination of both, such as the E61. This is a preferred choice for baristas as it provides a variety of benefits in one package.
As you can see from the above photo the head of the group is equipped with several notches. You place your portafilter in these notches, then twist the head to lock it. There is also a gasket of rubber in the notches to help create the seal when you insert your portafilter into the machine. The notches permit the precise placement of the portafilter. This is vital for an efficient extraction.
The group head not only lets you to insert your portafilter easily, but it also maintains the temperature at a constant level. This is accomplished by cycling hot water around the portafilter and through the brew-basket to ensure that the temperature is always at the right level for extraction. It is important to note that even a tiny variation can mean the difference between a good and great espresso.
The Pump
In contrast to piston machines that are manually operated, which use a lever to pressurize water, Rotary espresso machines rely on motorized pumps to deliver 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 tend to be cheaper and last longer than piston-driven machines. However, both types of machines are susceptible to degrading due to excessive use and poor cleaning. Pumps are also more complicated mechanically, which can increase the cost of even simple models.
Certain espresso machines remove the pump entirely and make use of steam pressure to make espresso. This can lead to over-extraction as the boiler that makes steam also heats the water to boil. The machines must also constantly rebuild their pressure between cups. This takes energy and time.
A majority of espresso machines utilize an rotary or a vibration pump. A vibration model makes use of a rotating disk to generate pressure, whereas the 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 what will heat the water to the perfect temperature to extract. The resultant steam then reaches the portafilter that contains ground espresso beans and is then pumped down into the cup. The steam generates enough pressure to push the coffee grounds through. This creates a crema on the
top espresso machines of the espresso. This is a sign of a good espresso.
There are three kinds of
professional espresso machine makers. They differ in the type of pump they employ and the degree of heat that the espresso is. There are many ways to control the brew as well as the size of the cup that can be made by the machine.
The first espresso machines were steam-based. They used one boiler to create both steam and brew but the pressure they could produce was not very high - two bars of atmospheric pressure, at most. The coffee tasted bitter and burned. The modern espresso machine was designed by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.
The most well-known espresso maker is a semiautomatic machine that has an electric pump. These are the images people have when they think of an espresso machine. With a semi-automatic machine, you must grind the beans and then tamp them by hand, but the pump provides regulated water flow and pressure. This is an excellent compromise between human touch and mechanized accuracy.
The Filter
Typically, espresso machines utilize a filter to separate out the grounds of coffee when they pass through the hot water. The filter is also a vital component of the temperature control system, as it keeps the machine from overheating.
A filter also helps with flavor because it allows for a longer flowering period. This helps the beans let their nuances out and provides an opportunity for a better extraction.
It is important to keep in mind that even the finest filter can produce a bad cup of coffee. The quality of the beans, and the extraction, remain vital.
It's in this area that the magic occurs. This is what makes espresso taste so good. 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 heated in an airtight container to create steam. The steam then pushes hot water into the grounds of coffee under high pressure. These types of machines are usually less expensive and simpler to maintain than pumps-driven models. However, they are not as efficient in their ability to produce the perfect conditions for brewing, since they are only operating at 1-1.5 bars of pressure. While the perfect shot requires 9-10 bar.
In recent years, compressed air-pump-driven espresso machines have been gaining popularity. They make use of an air compressor to push hot water through the
best ground coffee for espresso machine. They are also more mobile than electric steam-driven espresso machines.