10 Meetups About Machine Espresso You Should Attend

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. But how exactly does it work?

Espresso is made by forcing hot water at high pressure through finely-ground coffee. The process is similar to making drip coffee however the main difference lies in the pressure.

The Group Head

The group head is the portafilter that you put in when making espresso. It is responsible for dispersing the water into the portafilter before controlling the pressure that results from the extraction. There are various kinds of group heads, each with their own advantages and disadvantages. Some are designed to provide stability in temperature, while others are specifically designed to handle pre-infusion. Others are made to control the lever. Some come with a combination of both, such as the E61. This is a favorite among baristas because it offers multiple advantages in one package.

As you can see in the image above, the group head has several notches to put your portafilter, then twist it with your hands to lock it in. There is also a gasket of rubber in the notches and helps create an airtight seal after inserting your portafilter into the machine. The notches permit an exact placement of the portafilter. This is essential for an efficient extraction.

Apart from allowing you effortlessly insert your portafilter the group head is responsible for maintaining an even temperature. This is done by cycling hot water around the portafilter and through the brew-basket, making sure that the temperature is at the right level for extraction. This is crucial, since even a small difference in temperature can make the difference between good and excellent espresso.

The Pump

In contrast to piston machines that are manually operated, which rely on a lever that pressurize water, Rotary espresso machines rely on motorized pumps to provide the nine atmospheric bars of pressure necessary for espresso extraction. The pressure is built by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are generally less expensive than piston-driven machines, and they tend to last longer. However, both types of machines could be damaged by excessive use and inadequate cleaning. Pumps are also more complicated mechanically, which could increase the cost of even most basic models.

Some espresso machines do away with the pump entirely and utilize steam pressure to make espresso. This can lead to over-extraction as the boiler that produces steam also heats the water until it comes to a boil. Additionally, these machines frequently have to restore their pressure between cups, which requires time and energy.

Many espresso machines use either a vibration or rotary pump. A vibration model utilizes a vibrating disk to generate pressure, whereas a circular model pushes hot liquid through the ground at a rapid speed. Both machines can make excellent espresso but rotary machines are more quiet, durable and less likely to break.

The Boiler

The boiler is the component that heats water to an optimal temperature for extraction. The resulting steam reaches the portafilter, which contains ground espresso beans and is then funneled down into the cup. The steam generates enough pressure to push the coffee grounds through. This produces a layer of crema that is then poured over. This is a sign of a good espresso.

There are three kinds of espresso machines, each with distinct pumps and brew temperature. There are many ways to control the brew and the size of cup that can be made by the machine.

italian espresso machine were steam-type. The earliest espresso machines were steam-type machines. This resulted in the coffee tasting bitter and burnt. This is the reason Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.

The most popular espresso maker is a semi-automatic machine with an electric pump. These are what people imagine when they think of an espresso maker. With a semi-automatic machine, you must grind the beans and then tamp them yourself but the pump provides regulated water flow and pressure. This is a great compromise between the human touch and mechanized quality.


The Filter

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

A filter can also help with flavor as it allows for the beans to flower for a longer period of time. This allows the beans to release their nuances, and allows for better extraction.

However it is crucial to keep in mind that even a top filter can result in a poor cup of coffee as the quality of the beans and extraction is essential.

This is where the magic happens, and it's what makes espresso taste good. The grouphead, also referred to as the brew head, is where the portafilter (the thingy you put the ground coffee into) is placed when making espresso.

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

In recent years, compressed air-driven espresso machines have been gaining popularity. They use an air-compressor to force hot water into the ground and are more mobile than electric steam-driven espresso machines.

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Pub: 02 Apr 2024 22:24 UTC
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