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

• 페이스북 공유
• 트위터 공유
• 

How Does Machine Espresso Work?

The machine espresso is made using precision pressure, and a filtering system that is awe-inspiring to create the coffee you love. What exactly is it?

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 major difference is in the pressure.

The Group Head

The group head is the portafilter that you insert when brewing espresso. It disperses water in the portafilter, and regulates the pressure of extraction. There are many different kinds of group heads each with its particular advantages and drawbacks. Some are designed for stability in temperature, while others are designed to handle pre-infusion. Some are designed to control the lever. There are some that contain a variety of features, such as the E61 one, which is to be the most popular among baristas due to its capacity to provide multiple benefits in one package.

As you can see from the above photo the head of the group has a number of notches. It is possible to place your portafilter in these notches and then twist the head to secure it. There is also a gasket of rubber that is a part of the notches and helps to create an airtight seal after inserting your portafilter into the machine. The notches on the head permit a precise positioning of the portafilter which is vital for an even extraction.

The group head not only allows you to insert your portafilter easily, but it also maintains the temperature at a constant level. This is achieved 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 important, as even a small difference in temperature can mean 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 supply the nine atmospheric bars of pressure that are required for espresso extraction. The pressure is built by pumping water through a heat exchanger and then through the ground coffee.

Pumps are typically less expensive and last longer than piston-driven machines. However, both types of machines can deteriorate because of excessive use and inadequate cleaning. Pumps are also more complicated mechanically, and can add to the cost of even the simpler models.

Some espresso machines employ steam pressure instead of a pump to brew espresso. The disadvantage of this is that the same dual boiler espresso machine (she said) that produces steam also raises the temperature of the water to the point of boiling which can cause excessive extraction. The machines must also continuously rebuild their pressure between cups. This takes energy and time.

A majority of espresso machines espresso machines utilize either a vibration or rotary pump. A vibration model uses a vibrating disk to generate pressure, whereas a circular model pushes hot liquid through the ground at a high speed. Both types of machine can make a great espresso, however rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the one that heats the water to the ideal temperature to extract. The steam produced gets to the portafilter which holds the espresso grounds. The steam is then channeled into the cup. The steam creates pressure and pushes through the coffee grounds. This results in a whipped-up top of the espresso. This is one of the main characteristics of a great espresso.

There are three kinds of espresso machines, each having distinct pumps and brew temperature. There are various ways that the brew may be controlled and the dimensions of the cup the machine can produce.

The first espresso machines were steam types. The earliest espresso machines were steam types. The coffee tasted bitter and burned. The modern espresso machine was developed by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most popular espresso machine is a semiautomatic with an electric pump. These are the things people think of when they imagine an espresso machine. With a semi-automatic espresso machine, you need to grind the beans and tamp them by hand. However, the pump controls the flow of water and pressure. This is an excellent compromise between human touch and mechanized quality.

The Filter

Typically, espresso machines utilize filters that separate the coffee grounds as they pass through the hot water. The filter is also an important component of the temperature control system, since it helps prevent the machine from overheating.

A filter also helps with flavor as it allows for a longer flowering phase. This allows the beans to release their flavor and allows for a better extraction.

However, it is important to remember that even a great filter can make a terrible cup of coffee as the quality of the beans and extraction are important.

It's here that the magic happens. This is the reason why espresso tastes so good. The grouphead, often called the brewhead, is where the portafilter (the container you place the ground coffee and espresso machine into) is placed when making espresso.

In a steam-driven espresso machine, hot water is heated in an airtight container to create steam. Steam then pushes the hot water through the grounds at a high end espresso machine pressure. They are less expensive and easier for the owner to maintain than pumps-driven models. They are however limited for creating the ideal brewing conditions 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 been gaining popularity. They utilize an air compressor to push hot water across the ground and are much more mobile than steam-driven electric espresso machines.