10 Tell-Tale Signs You Need To Buy A Machine Espresso

How Does Machine Espresso Work?

The machine espresso is made using precision pressure, and filtering system that is awe-inspiring to create the coffee you love. How exactly does it work?

To make an espresso, hot water is forced under high end espresso machine (browse around here) pressure through finely ground coffee. The process is similar to that of making drip coffee. However the pressure is the main difference.

The Group Head

The group head is the portafilter you put in when making espresso. It is responsible for dispersing the water into the portafilter and controlling the pressure of the resulting extraction. There are many different types of group heads each with distinct advantages and drawbacks. Some are focused on temperature stability, some on pre-infusion options, and others are designed to control the lever. Some include a combination like the E61. This is a very popular choice for baristas since it provides multiple benefits in one package.

As you can see in the photo above, the group head has several notches where you place your portafilter and then twist it manually to secure it. A gasket made of rubber is positioned inside the notches, which helps create a seal while you insert your portafilter. The notches on the head permit an exact position of the portafilter which is vital to ensure a consistent extraction.

The group head not only allows you to place 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. This is crucial, since even a few degrees can make the difference between a good and great espresso.

The Pump

In contrast to manual piston machines which use a lever to pressurize water, rotating espresso machines rely upon motorized pumps that provide the nine atmospheric bars of pressure that are 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 generally less expensive and last longer than piston-driven machines. However, both kinds of machines are susceptible best bean to cup espresso machine degrading due to overuse and insufficient cleaning. They also increase the complexity of mechanical systems and can lead to a high price tag on even the simplest models.

Some espresso machines use steam pressure instead of a pump to make espresso. The drawback of this is that the same boiler that produces steam also raises the temperature of the water to the point of boiling which could lead to over-extraction. Additionally these machines are often required to restore their pressure between cups, which takes time and energy.

Many espresso machines make use of either a vibration or rotary pump. A vibration model utilizes the vibrating disk to create pressure, whereas a Rotary model pushes hot coffee through the ground at a fast speed. Both types of machines can produce an excellent espresso, but the rotary pumps 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 steam that is created reaches the portafilter, which is the container that holds the espresso coffee grounds. It is then funneled into the cup. The steam generates enough pressure to push the grounds of the coffee and espresso machine through. 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. They differ in the kind of pump they use and how hot the coffee and espresso machine is. There are also different ways that the brew can be controlled and the size of the cup that the machine can make.

The first espresso machines were steam types. They utilized only one boiler to make steam and brew, however the pressure they were able to produce was very low - just two bars of atmospheric pressure maximum. The coffee tasted bitter and burned. The modern espresso machine was developed by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso maker is a semi-automatic machine with an electric pump. When people think of espresso machines, they envision these machines. If you have a semi-automatic machine you must grind the beans and then tamp them yourself but the pump controls the flow of water and pressure. This is a great compromise between the human touch and the mechanized accuracy.

The Filter

Typically, espresso machines have filters to separate the grounds of coffee as they move through the hot water. The filter is also an essential element of the machine's temperature control, since it stops overheating.

A filter can also help with flavor as it allows for an extended flowering time. This helps the beans release their nuances and gives an opportunity to improve 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 are important.

It's in this area that the magic takes place. This is what makes espresso taste so good. The grouphead, often called the brewhead, is where the portafilter (the container you place the coffee ground into) is placed when making espresso.

In a steam-driven espresso machine, hot water is heated in an airtight container to produce steam, which then pushes the hot water through the grounds with high pressure. They are less expensive and are easier for the user to maintain than pumps-driven models. However, they are not as efficient in their ability to produce the perfect conditions for brewing, since they operate at 1-1.5 bars of pressure. 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 grounds and are much more portable than steam-driven electric machines.