It s The Ugly Truth About Machine Espresso

How Does Machine Espresso Work?

Machine espresso uses precision pressure and mind-blowing filter technology to make the perfect cup of coffee. How exactly does it work?

Espresso is made by pushing hot water 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

As the name implies, the group head is the place you place your portafilter when brewing espresso. It disperses water in the portafilter, and regulates the pressure of extraction. There are a variety of group heads, each with its own advantages and drawbacks. Some are specifically designed for temperature stability while others are built to handle pre-infusion. Some are designed to control the lever. Some have a combination, such as the E61. This is a very popular choice for baristas due to the fact that it has multiple benefits in one package.

As you can see in the above photo the group head is fitted with several notches. You can place your portafilter in these notches, then turn the head around to secure it. A rubber gasket is located inside the notches, which helps create a seal when you insert your portafilter. The notches on the head permit an exact placement of the portafilter, which is crucial to ensure a consistent extraction.

The group head not only lets you to put in your portafilter 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 is always at the correct temperature for extraction. This is vital, because even a small difference in temperature can mean the difference between good and great espresso.

The Pump

Unlike manual piston machines, that use a lever to pressurize water, Rotary espresso machines rely on motorized pumps to supply the nine atmospheric bars of pressure needed to extract espresso. The pressure builds up by removing tap water from a reservoir and pumping it through a heat exchanger before being shot through the ground coffee inside the group head.

Pumps tend to be less expensive and last longer than piston-driven machines. However, both types of machines can degrade due to overuse and inadequate cleaning. Pumps are also more complex mechanically, which can raise the price of even the simple models.

Some espresso machines eliminate the pump entirely and employ steam pressure to create espresso. This could lead to over-extraction since the boiler that produces steam also heats the water until it comes to a boil. These machines also have to continuously rebuild their pressure between cups. This requires energy and time.

Many espresso machine with grinder machines make use of either a vibration or rotary pump. A vibration model utilizes a vibrating disk to generate pressure, whereas a rotating model pushes hot water through the ground at a high speed. Both types of machines can make a great espresso, however rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the part that heats the water to the ideal temperature for extraction. The steam created is then directed to the portafilter, which is the container that holds the espresso coffee grounds. The steam is then channeled into the cup. In this process, the steam creates pressure and pushes through the coffee grounds. This results in a layer of crema on top. This is one of the main characteristics of a great espresso.

There are three kinds of home espresso machine makers. They differ in the type of pump they use and the degree of heat that the brew is. There are various ways that the brew can be controlled as well as the size of the cup that the machine can produce.

The first espresso machines were steam-types. They used one boiler to create both steam and brew, however the pressure they were able to produce was not very high - two bars of atmospheric pressure at most. The coffee tasted bitter and burned. This is the reason Milanese producers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most common espresso maker is a semi-automatic device that has an electric pump. These are the images people have when they imagine an espresso coffee makers machine. If you have 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 fantastic compromise between human control and mechanized consistency.

The Filter

Typically, best budget espresso machine (click homepage) machines employ filters to separate the grounds of coffee when they pass through the hot water. The filter is also a vital element of the temperature control system, as it prevents the machine from overheating.

It also improves flavor as a filter can allow for a longer bloom time. This allows beans to release their nuances and gives the chance for better extraction.

However it is crucial to remember that even a top filter could result in a bad cup of coffee, since the quality of the beans and extraction is crucial.

It's in this area that the magic occurs. This is what makes espresso taste so delicious. The grouphead (also called the brewhead) is where you put the portafilter, the thingy that you put the grounds of coffee into when making espresso.

Steam-driven espresso 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 machines are cheaper and easier for the owner to maintain than pumps-driven models. However, they are limited in their ability to create the ideal conditions for brewing since they are only operating 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 become more popular. They use an air compressor to push hot water across the ground and are much more mobile than electric steam-driven espresso coffee machine home machines.