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

How Does Machine Espresso Work?

Machine espresso utilizes precise pressure and mind-blowing filter technology to make the coffee we love. What exactly is it that makes it work?

In order to make espresso, hot water is pushed under pressure through finely ground coffee. The process is similar to making drip coffee, but the major difference is in the pressure.

The Group Head

As the name implies, the group head is where you place your portafilter when making espresso. It is responsible for dispersing the water into the portafilter and controlling the pressure of the extraction. There are many different types of group heads each with distinct advantages and drawbacks. Some are specifically designed for stability of temperature while others are built to handle pre-infusion. Some are designed to control the lever. Some include a combination such as the E61. This is a very popular choice for baristas as it provides a variety of benefits in a single package.

As you can see in the image above the group head is made up of several notches where you place your portafilter and then twist it manually to lock it in. A gasket of rubber is situated inside the notches to help create a seal when you insert your portafilter. The notches on the head allow for an exact positioning of the portafilter which is essential Bean to cup espresso machines ensure an even extraction.

Aside from allowing you to easily connect your portafilter, the group head is also responsible to ensure that the temperature remains even. This is done by cycling hot water around the portafilter, and through the brew-basket to ensure that the temperature is always at the right level to extract the coffee. It is important to remember that even a few degree deviation can make the difference between a good and excellent espresso.

The Pump

The motorized pumps used in espresso machines that rotate provide the nine atmospheric bar pressure required to extract espresso. This is different from manually operated piston machines that employ a lever. The pressure is created by pumping water through a heat exchanger and then through the ground coffee.

Pumps tend to be less expensive and last longer than piston-driven machines. However, both kinds of machines may degrade due to excessive use and insufficient cleaning. They also increase the complexity of mechanical systems which can result in the cost of even the simplest models.

Some espresso machines employ steam pressure instead of a pump to make espresso. The disadvantage of this is that the same boiler that produces steam also raises the temperature of the water to boiling which can cause excessive extraction. The machines must also constantly rebuild their pressure in between cups. This requires energy and time.

Many espresso machines utilize an rotary or vibrating pump, which is a vibration model using a rotating disc that generates the pressure and the rotary model pushing hot water through the grounds under high speed. Both machines can make excellent espresso coffee maker, but rotary machines are more quiet, durable and less likely to fail.

The Boiler

The boiler is the one that heats the water to the perfect temperature to extract. The steam that is produced gets to the portafilter which is a container for espresso grounds. It is then pumped into the cup. The steam causes enough pressure to push the coffee grounds through. This results in a layer crema on top. This is one of the hallmarks of a great espresso.

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

The first espresso machines were steam-based. The earliest espresso machines were steam types. This resulted in the coffee tasting burnt and bitter. The modern espresso machine was invented by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.

The most common espresso maker is a semi-automatic one with an electric pump. These are the things people think of when they think of an espresso maker. If you have a semi-automatic machine you have to grind the beans and then tamp them by hand. The pump provides regulated water flow and pressure. This is a perfect compromise between human control and mechanised accuracy.

The Filter

Typically, espresso machines use a filter to separate out the grounds of the coffee as they go through the hot water. The filter is also a vital component of the machine's temp control, as it prevents overheating.

A filter can also help with flavor, as it permits a longer flowering phase. This lets the beans release their flavors, and also allows for better extraction.

However, it is important to remember that even a high-quality filter can make a terrible cup of coffee, because the quality of the beans and extraction is still essential.

This is where the magic happens, it's the thing that makes an espresso really taste good. The grouphead (also known as the brewhead) is where you place the portafilter, the device that you use to put the grounds of your coffee into when making espresso machine with milk frother.

Steam-driven espresso machines use hot water heated in an airtight vessel to create steam. The steam then pushes hot water into the grounds of coffee for espresso machine under high pressure. These kinds of machines are usually less expensive and simpler to maintain than pump-driven models. However, they are limited in their ability to create the perfect conditions for brewing, since they operate 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 have become increasingly popular. They use an air compressor to force hot water into the grounds and are much more portable than steam-driven electric machines.