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

How Does Machine Espresso Work?

Machine espresso employs precise pressure and incredible filter technology to produce the perfect cup of coffee. How exactly does 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 Head of the Group

As the name suggests the group head is the place you insert your portafilter when brewing espresso. It disperses the water into the portafilter and controls the pressure of the extraction. There are many different kinds of group head each with its own advantages and drawbacks. Some are focused on temperature stability, whereas others on pre-infusion capabilities, while others are designed to control the lever. Some are a combination, such as the E61. This is a very popular choice for baristas since it provides multiple benefits in a single package.

As you can see in the image above the group head comes with many notches in which you can place your portafilter before twisting it with your hands to secure it. There is also a gasket made from rubber which is located inside the notches to help create the seal when you insert your portafilter into the machine. The notches allow for precise placement of your portafilter. This is crucial for an accurate extraction.

In addition to allowing you effortlessly insert your portafilter the group head is also responsible to ensure that the temperature remains even. It does this by cycling hot water through the brew basket, and around the portafilter, ensuring that it is always at the correct temperature for extraction. This is vital, because just a few degrees could be the difference between a excellent and great espresso.

The Pump

Motorized pumps in espresso machines rotary provide nine atmospheric bar pressure that is required for espresso extraction. This is different from manual piston machines which use a lever. The pressure is created by drawing tap water from a reservoir and pumping it through a heat exchanger prior it is shot through the ground coffee inside the group head.

Pumps are typically less expensive and last for longer than piston-driven machines. However, both kinds of machines can degrade because of excessive use and insufficient cleaning. Pumps are also more complicated mechanically, which could increase prices of even most basic models.

Certain retro espresso maker machines can eliminate the pump completely and instead utilize steam pressure to make espresso. The drawback is that the boiler that produces steam also raises the temperature of the water until it reaches boiling and can result in excessive extraction. In addition these machines are often required to rebuild their pressure between cups, which requires time and energy.

Many espresso machines make use of a rotary or vibration pump. A vibration model uses a rotating disk to generate pressure, whereas a Rotary model pushes hot coffee through the ground at high speed. Both models can make a great espresso, however the rotary models are quieter and more durable than vibration pumps.

The Boiler

The boiler is the part that heats the water to the optimal temperature for extraction. The steam produced gets to the portafilter which is the container that holds the espresso coffee grounds. The steam is then channeled into the cup. The steam causes enough pressure to push the grounds of coffee through. This creates a foam on the top of the espresso. This is a hallmark of a great espresso.

There are three kinds of espresso makers, and they differ in the kind of pump they use and how hot the brew is. There are also different ways in which the brew can be controlled, as well as the size of the cup the machine is capable of making.

The first espresso maker machines were steam-based. They employed only one boiler to make both steam and brew however the pressure they were able to produce was very low - just two bars of atmospheric pressure at most. This resulted in the coffee tasting bitter and burnt. This is the reason why Milanese producers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most well-known espresso machine is a semiautomatic with an electric pump. This is what people envision when they think of an espresso maker. Semi-automatic machines require you to grind and tamp the beans on your own The pump, however, regulates the water flow and pressure. This is an excellent compromise between human touch and the mechanized consistency.

The Filter

Espresso machines usually have filters that separate the grounds of the coffee from the hot water. The filter is also an essential part of the machine's temperature control, since it helps to prevent overheating.

Filters also aid in flavor because it allows for the beans to flower for a longer period of time. This allows the beans to let their nuances out, and allows for a better extraction.

However, it is important to keep in mind that even a high-quality filter can produce a bad cup of coffee, as the quality of the beans and extraction is vital.

It's here that the magic takes place. This is the reason why espresso tastes so good. The grouphead, also referred to as the brewhead, is where the portafilter (the thingy you put the ground coffee into) is located when you're making cafe espresso machine.

In a steam-driven espresso machine hot water is heated in an airtight container to create steam. This is then pushed through the grounds at a high pressure. They are less expensive and are easier for the user to maintain than pumps-driven models. However, they are not as efficient in their ability to produce the ideal brewing conditions, since they are only operating at 1-1.5 bars of pressure. However, the perfect shot requires 9-10 bar.

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