This Is The Ugly Truth About Machine Espresso

How Does Machine Espresso Work?

The machine espresso makes use of precision pressure, and filter technology that is awe-inspiring to make the coffee you enjoy. How does it work exactly?

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 difference is in the pressure.

The Head of the Group

As the name implies, the group head is the place you place your portafilter when making espresso. It disperses the water into the portafilter, and regulates the pressure of extraction. There are several different types of group heads, each with their own advantages and disadvantages. Some are focused on temperature stability, while others on pre-infusion options, and others are designed to control the lever. Some come with a combination of both, like the E61. This is a very popular choice for baristas since it provides multiple advantages in one package.

As you can see in the above image, the group head has several notches where you place your portafilter before twisting it by hand to secure it. A gasket made of rubber is positioned inside the notches to help make a seal when you insert your portafilter. The notches on the head allow for an exact placement of the portafilter, which is essential for an efficient extraction.

The group head not only lets you to insert your portafilter easily however, it also keeps the temperature at a constant level. This is done by cycling hot water around the portafilter and through the brew basin, ensuring the temperature is always right to extract the coffee. It is important to remember that even a few degree difference can make the difference between a good and excellent espresso.

The Pump

In contrast to manual piston machines that use a lever to pressurize water, rotary espresso machines rely on motorized pumps that provide the nine atmospheric bars of pressure required for barista Espresso coffee machine extraction. This pressure builds up by removing tap water from a reservoir and pumping it through a heat exchanger prior to being pushed through the ground coffee machine espresso in the group head.

Pumps are generally less expensive than piston-driven machines, and they tend to last longer. However, both types of machines can get damaged through overuse and lack of cleaning. Pumps are also more complicated mechanically, which can increase the cost of even most basic models.

Some espresso machines can eliminate the pump completely and instead employ steam pressure to create espresso. The downside is that the same boiler that produces steam also raises the temperature of the water to boiling which could lead to over-extraction. These machines also have to constantly rebuild their pressure in between cups. This takes energy and time.

Many espresso machines make use of an rotary or vibrating pump, which is a vibration model that uses a vibrating disc to create pressure, and the rotary model pushing hot water through the grounds at high speed. Both models can make a great espresso, however the rotary pumps are quieter, and more durable than vibration pumps.

The Boiler

The boiler is the one that will heat the water to the ideal temperature for extraction. The resulting steam is then transferred to the portafilter, which contains the ground espresso and is then pumped down into the cup. The steam causes pressure to push through the coffee grounds. This produces a layer of crema that is then poured over. This is a sign of a great espresso.

There are three kinds of espresso makers. They differ in the type of pump they use and the degree of heat that the coffee is. There are many ways to control the strength of the brew and the size of cup that can be made by the machine.

The earliest espresso machines were steam types. They used only one boiler to make both brew and steam, however the pressure they were able to produce was not very high - two bars of atmospheric pressure maximum. This resulted in the coffee for espresso machine tasting burnt and bitter. The modern travel espresso maker machine was designed by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.

The most popular espresso machine is a semiautomatic one with an electric pump. This is what people envision when they think of an espresso machine. Semi-automatic machines require you to grind and tamp your beans yourself however the pump controls the flow of water and pressure. This is a great compromise between the human touch and the mechanised consistency.

The Filter

Espresso machines typically have filters that separate the grounds of the coffee from hot water. The filter is also a vital component of the temperature control system, as it keeps the machine from overheating.

Filters also aid in flavor, as it permits a longer flowering period. This allows beans to release their flavors and provides an opportunity for better extraction.

It is important to remember that even the most efficient filter can make a bad cup of coffee. The quality of the beans and the extraction, remain vital.

It's in this area that the magic takes place. This is the reason why espresso tastes so good. The grouphead, sometimes referred to as the brew head, is the place where the portafilter (the device you put the ground coffee into) sits when you're making espresso.

In a steam-driven espresso machine, hot water is heated in an airtight tank to create steam. Steam then pushes the hot water through the grounds at high pressure. They are less expensive and easier for the owner to maintain than pumps-driven models. However, they are not as efficient in their ability to provide the ideal brewing conditions, since they are only operating at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bar.

In recent years, espresso machines powered by compressed air-pump are becoming increasingly popular. They make use of an air compressor to push hot water across the ground and are much more mobile than steam-driven electric espresso machines espresso machines.