• 목록
• 답변
• 글쓰기
• 게시판 리스트 옵션
  • 수정
  • 삭제

How Does Machine Espresso Work?

Machine espresso utilizes precise pressure and amazing filter technology to make the delicious coffee we enjoy. How does it work exactly?

Espresso is produced by pushing hot water under 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 name implies the group head is the place you put your portafilter in when brewing espresso. It is responsible for dispersing the water into the portafilter before controlling the pressure of the extraction. There are many different kinds of group head, each with their unique advantages and disadvantages. Some are designed for the stability of temperature while some are built to handle pre-infusion. Some are designed to control the lever. There are some that come with a range of features, like the E61, which is to be the most popular among baristas because of its ability to offer multiple benefits in one package.

As you can see in the above image the group head comes with numerous notches that you can place your portafilter and twist it with your hands to secure it. There is also a rubber gasket in the notches and helps to create a seal when you insert your portafilter into the machine. The notches on the head permit an exact location of the portafilter which is essential for a consistent extraction.

In addition to allowing you to easily connect your portafilter, the group head is also responsible for maintaining an even temperature. This is done by cycling hot water around the portafilter, and through the brew-basket, ensuring the temperature is always right for extraction. It is important to remember that even a small deviation can make the difference between a decent and a great espresso.

The Pump

Unlike manual piston machines, which rely on a lever to pressurize water, rotary espresso machines espresso rely on motorized pumps to provide the nine atmospheric bars of pressure needed for espresso extraction. The pressure is created by removing tap water from a reservoir and pumping it through a heat exchanger prior being pushed through the ground coffee inside the group head.

Pumps tend to be more affordable and last longer than piston-driven machines. However, both kinds of machines are susceptible to degrading because of excessive use and poor cleaning. Pumps are also more complicated mechanically, which can raise prices of even simpler models.

Certain espresso machines (see this page) remove the pump completely and instead make use of steam pressure to make espresso. The drawback of this is that the same boiler that produces steam also raises the temperature of water until it reaches boiling which can cause excessive extraction. Additionally these machines typically have to restore their pressure between cups, which takes time and energy.

Many espresso machines utilize an rotary or vibrating pump, which is a vibration model that uses a vibrating disc to create pressure, and a rotary model pushing hot water through the grounds under high speed. Both machines can make excellent espresso, but rotary machines are quieter, more durable and less likely to break down.

The Boiler

The boiler is the element that heats water to an ideal temperature for extraction. The resulting steam is then transferred to the portafilter which holds the ground espresso coffee, and is then funneled down into the cup. The steam creates pressure that pushes through the coffee grounds. This results in a crema on the top of the espresso. This is a sign of a good espresso.

There are three different types of espresso machines, each having a different type of pump and the temperature of the brew. There are different ways that the brew may be controlled as well as the dimensions of the cup the machine can produce.

The earliest espresso machines were steam type. The first espresso machines were steam-type machines. The coffee tasted bitter and burned. This is the reason why Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni developed the modern espresso machine.

The most common espresso machine is a semiautomatic with an electric pump. When people think of espresso machines, they imagine these machines. With a semi-automatic espresso machine, you grind the beans and tamp them by hand. The pump controls the flow of water and pressure. This is an excellent compromise between human touch and the mechanised accuracy.

The Filter

Typically, espresso machines use filters that separate the grounds of the coffee as they go through the hot water. The filter is also an essential component of the temperature control system, because it stops the machine from overheating.

It also enhances flavor, since a filter allows for a more prolonged bloom phase. This allows beans to release their flavors and provides the chance for better extraction.

However it is crucial to keep in mind that even a top filter can result in a poor cup of coffee and espresso maker, because the quality of the beans and extraction is vital.

This is where the magic happens, it's the thing that makes espresso taste good. The grouphead, often called the brew head, is where the portafilter (the thing you put the ground coffee in) is placed when making espresso.

Steam-driven espresso machines use hot water that is heated inside an airtight container to produce steam. The steam then pushes hot water through the coffee grounds under high pressure. These kinds of machines are typically less expensive and easier to maintain than pumps-driven models. They are however limited for creating the ideal 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-driven espresso machines have become more popular. They make use of an air compressor to push hot water through the ground and are much more mobile than steam-driven electric professional espresso machine for home machines.