A Look At The Ugly Truth About Machine Espresso

How Does Machine Espresso Work?

The machine espresso uses precision pressure, and filter technology that is mind-blowing to make the coffee you love. How exactly does it work?

Espresso is made by forcing hot water under pressure through finely-ground coffee. The process is similar to making drip coffee. However, the pressure is the primary difference.

The Head of the Group

As the name implies, the group head is where you place your portafilter while making espresso. It is responsible for dispersing water into the portafilter and then controlling the pressure of the extraction. There are a variety of group heads, each with its own advantages and disadvantages. Some are focused on temperature stability, some on pre-infusion options, and others are designed to control the lever. Some are a combination, like the E61. This is a preferred choice for baristas because it offers multiple advantages in a single package.

As you can see in the above image, the group head has many notches in which you can place your portafilter and then twist it manually to secure it. A gasket made of rubber is placed within the notches to make a seal when you insert your portafilter. The notches allow for precise placement of the portafilter. This is essential for an accurate extraction.

The group head is not just able to allow you to put in your portafilter easily, but it also maintains a constant temperature. This is achieved by cycling hot water around the portafilter and through the brew-basket, making sure the temperature is always right for extraction. This is important because just a few degrees could make the difference between excellent and great espresso.

The Pump

The motorized pumps that are used in espresso machines rotary provide nine atmospheric bar pressure required for espresso extraction. This is different from manual piston machines that use levers. The pressure is built by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are generally less expensive and last longer than piston-driven machines. However, both kinds of machines can deteriorate due to excessive use and insufficient cleaning. Pumps are also more complex mechanically, which can raise the cost of even the simple models.

Some espresso machines remove the pump completely and instead employ steam pressure to create espresso. The disadvantage of this is that the same boiler that produces steam also increases the temperature of the water to the point of boiling which can cause over-extraction. In addition the machines often have to restore their pressure between cups, which requires time and energy.

Many espresso machines make use of a vibration or rotary pump, which is a vibration model that uses a vibrating disc to create the pressure and an rotary model that pushes hot water through the grounds under high speed. Both machines can make great espresso however rotary machines tend to be quieter, more durable and less likely to fail.

The Boiler

The boiler is the one that is used to heat the water to the perfect temperature for extraction. The steam that is produced reaches the portafilter, which holds the espresso grounds. It is then pumped into the cup. During this process, steam creates pressure and pushes through the coffee grounds. This results in a crema on top of the espresso. This is one of the hallmarks of a great espresso.

There are three types of espresso machines, each having different pumps and brew temperature. There are various ways to control the brew and the size of the cup that can be produced by the machine.

The first espresso machines were steam-types. They used only one boiler to make both brew and steam, but the pressure they could generate was low - only two bars of atmospheric pressure maximum. The coffee tasted bitter and burnt. The modern espresso machine was designed by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most common espresso maker is a semi-automatic device with an electric pump. These are the things people think of when they think of an espresso maker. With a semi-automatic espresso machine, you have to grind the beans and tamp them by hand. The pump controls the flow of water and pressure. This is an excellent combination of human control and mechanized accuracy.

The Filter

Espresso machines typically have filters that separate the grounds of the coffee from the hot water. The filter is also a vital part of the machine's temperature control, as it helps prevent overheating.

It also improves flavor, since a filter allows for a longer bloom phase. 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 top filter can result in a poor cup of coffee, since the quality of the beans and extraction are vital.

This is where the magic happens, and it's what makes an espresso really taste go od. The grouphead, also referred to as the brew head, is where the portafilter (the container you place the ground coffee into) is located when you're making espresso.

In the steam-driven espresso machine hot water is heated in an airtight tank to create steam. Steam then pushes the hot water through the grounds under high pressure. These machines are cheaper and easier for the owner to maintain than pumps-driven models. They are however limited to create the perfect conditions for brewing as they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

In recent years, compressed-air-pump-driven espresso machines have become more popular. They make use of an air compressor to push hot water through the ground, and are more mobile than electric steam-driven espresso machines.

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Pub: 02 Apr 2024 17:34 UTC
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