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

How Does Machine Espresso Work?

The machine espresso uses precise pressure and filter technology that is awe-inspiring to make the coffee you love. How exactly does it work?

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

The Group Head

The group head is the portafilter you insert when brewing espresso. It is responsible for dispersing water into the portafilter, and controlling the pressure that results from the extraction. There are a variety of types of group heads each with its own advantages and drawbacks. Some are focused on temperature stability, whereas others on pre-infusion capabilities, and still others are designed to control the lever. Some are a combination, like the E61. This is a popular choice among baristas since it provides multiple benefits in a single package.

As you can see in the above image The group head features many notches in which you can place your portafilter and then twist it with your hands to secure it. A rubber gasket is located inside the notches to help create a seal as you insert your portafilter. The notches on the head permit an exact placement of the portafilter, which is vital to ensure an even extraction.

Apart from allowing you easily insert your portafilter, the group head is also responsible to maintain an even temperature. This is accomplished by cycling hot water around the portafilter, and through the brew basin, ensuring the temperature is always right for extraction. This is crucial, since even a few degrees can make the difference between a good and great espresso.

The Pump

In contrast to manual piston machines that use a lever to pressurize water, rotary espresso machines rely on motorized pumps to deliver the nine atmospheric bars of pressure required to extract espresso. The pressure is created by pumping water through a heat exchanger and then through the ground coffee.

Pumps tend to be more affordable and last longer than piston-driven machines. However, both types of machines can deteriorate due to overuse and insufficient cleaning. Pumps are also more complex mechanically, which can raise the cost of even most basic models.

Certain espresso machines eliminate the pump entirely and utilize steam pressure to make espresso. This can result in over-extraction because the boiler that produces steam also heats the water until it comes to a boil. They also have to continually rebuild their pressure between cups. This requires energy and time.

Many espresso machines utilize either a rotary or vibration pump, which is a vibration model using a rotating disc to generate the pressure and rotating models that push hot water through the grounds under high speed. Both machines produce great espresso but rotary machines are more quiet, durable and less likely to break.

The Boiler

The boiler is the one that will heat the water to the perfect temperature to extract. The resultant steam then reaches the portafilter containing ground espresso beans and is then funneled down into the cup. The steam causes enough pressure to push the grounds of coffee through. This results in a crema on top of the espresso. This is a hallmark of a great espresso.

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

The first espresso machines were steam types. The first espresso machines were steam types. The coffee tasted bitter and burnt. This is why the Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most popular espresso machine is a semiautomatic model with an electric pump. When people think of espresso machines, they picture these machines. Semi-automatic machines require you to grind and tamp your beans yourself however the pump controls the flow of water and pressure. This is an excellent compromise between human touch and the mechanised quality.

The Filter

Typically, espresso machines (read full article) employ a filter to separate out the grounds of the coffee as they go through the hot water. The filter is also a vital part of the machine's temperature control, since it helps to prevent overheating.

A filter also helps with flavor since it allows for an extended flowering time. This lets the beans release their flavors, and improves extraction.

However, it is important to keep in mind that even a high-quality filter could result in a bad cup of coffee, since the quality of the beans and extraction is important.

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

Steam-driven espresso machines use hot water that is heated in an airtight container to produce steam. The steam then pushes hot water through grounds of the coffee under pressure. These machines are less expensive and easier for the user to maintain than pumps-driven models. They are however limited to create 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 pump-driven espresso makers machines have become more popular. They use an air compressor to force hot water into the ground. They are also more mobile than electric steam-driven espresso machines.