9 . What Your Parents Teach You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso makes use of precise pressure and mind-blowing filter technology to create the perfect cup of coffee. But how exactly does it work?

Espresso is created by forcing hot water under pressure through finely ground coffee. The process is similar to that of making drip coffee. However the pressure is the major difference.

The Head of the Group

The group head is the portafilter you put in when making espresso. It is responsible for dispersing water into the portafilter before controlling the pressure that results from the extraction. There are numerous kinds of group heads each with their own advantages and disadvantages. Some are focused on temperature stability, others on pre-infusion capabilities, while others are designed to control the lever. Some are a combination, such as the E61. This is a favorite among baristas due to the fact that it has multiple advantages in one package.

As you can see in the photo above The group head features several notches to put your portafilter, then twist it with your hands to lock it in. A gasket made of rubber is placed within the notches to make a seal when you insert your portafilter. The notches on the head allow for an exact location of the portafilter which is essential for an efficient extraction.

The group head not only allows the portafilter to be inserted easily however, it also keeps the temperature at a constant level. This is accomplished by cycling hot water around the portafilter and through the brew-basket, ensuring the temperature is always right for extraction. This is important because even a small espresso machine difference in temperature can make the difference between a excellent and great espresso.

The Pump

In contrast to piston machines that are manually operated, which use a lever to pressurize water, the rotary espresso machines use motorized pumps to supply the nine atmospheric bars of pressure that are required to extract espresso. The pressure is created by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are generally more affordable and last longer than piston-driven machines. However, both types of machines can degrade due to overuse and insufficient cleaning. Pumps are also more complex mechanically, which can raise the price of even the simpler models.

Some espresso machines use steam pressure instead of a pump to brew espresso. The drawback of this is that the boiler that produces steam also increases the temperature of the water to boiling which can cause over-extraction. In addition, these machines frequently have to rebuild their pressure between cups, which requires time and energy.

A majority of espresso machines use a vibration or rotary pump, with a vibrating model using a vibrating disc that generates the pressure and an rotary model that pushes hot water through the grounds at high speed. Both types of machines are capable of producing excellent espresso, but the rotary models are quieter and more durable than vibration pumps.

The Boiler

The boiler is the part that heats the water to the optimal temperature to extract. The resultant steam then reaches the portafilter, which contains the ground espresso coffee and is then pumped into the cup. The steam creates enough pressure to push the grounds of the coffee through. This results in a layer of crema that is then poured over. This is the hallmark of a great espresso.

There are three kinds of espresso makers, which differ in the kind of pump they use and how hot the coffee is. There are many ways to control the strength of the brew and the size of the cup that can be produced by the machine.

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

The most popular espresso machine is a semiautomatic that has an electric pump. These are the images people have when they think of an espresso machine. Semi-automatic machines require you to grind and tamp the beans yourself The pump, however, regulates the water flow and pressure. This is a fantastic combination of human control and mechanized reliability.

The Filter

Espresso machines typically use a filter that separates the grounds of coffee from hot water. The filter is also a vital component of the machine's temp control, as it helps prevent overheating.

A filter also helps with flavor since it allows for an extended flowering time. This helps the beans to release their flavors and provides an opportunity for better extraction.

However, it is important to keep in mind that even a great filter can make a terrible cup of coffee, as the quality of the beans and extraction is still vital.

It's here that the magic happens. This is what makes espresso machine uk taste so delicious. The grouphead (also called the brewhead) is where you put the portafilter - the thingy that you use to put the coffee grounds into, when making espresso.

Steam-driven best espresso machine under 200 machines make use of hot water that is heated inside an airtight container to create steam. The steam then pushes hot water through grounds of the coffee under pressure. These kinds of machines are generally less expensive and simpler to maintain than pumps-driven models. However, they are not as efficient in their ability to create the ideal conditions for brewing since they are only operating at 1-1.5 bars of pressure. The perfect shot requires 9-10 bars.

In recent years, compressed air-driven espresso machines have become more popular. They utilize an air compressor to push hot water through grounds and are much more portable than electric steam-driven machines.