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

• 페이스북 공유
• 트위터 공유
• 

How Does Machine Espresso Work?

Machine espresso utilizes precise pressure and mind-blowing filter technology to create the perfect cup of coffee. What exactly does it work?

Espresso is produced by pushing hot water under pressure through finely ground coffee. The process is similar to making drip coffee, but the difference is in the pressure.

The Group Head

The group head is the portafilter you put in when making espresso. It disperses the water into the portafilter, and regulates the pressure of 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 features, and others are designed to control the lever. Some have a combination of features, like the E61 one, which is the most popular choice among baristas due to its ability to offer multiple perks in one package.

As you can see in the image above the group head is made up of several notches to place your portafilter and then twist it with your hands to lock it in. There is also a gasket of rubber which is located inside the notches, which helps create the seal when you insert your portafilter into the machine. The notches on the head allow for a precise placement of the portafilter, which is crucial for an efficient extraction.

The group head not only lets you to place your portafilter easily but also maintains a constant temperature. It does this by cycling hot water through the brew basket, and around the portafilter, making sure that it is always at the correct temperature to extract. This is vital, because just a few degrees could be the difference between a good and great espresso coffee machines for sale.

The Pump

In contrast to manual piston machines which use a lever to pressurize water, rotary espresso machines rely on motorized pumps that provide the nine atmospheric bars of pressure needed to extract espresso. 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 less expensive and last longer than piston-driven machines. However, both kinds of machines can deteriorate due to overuse and inadequate cleaning. Pumps are also more complicated mechanically, and can add to the cost of even the most basic models.

Some espresso machine with Grinder machines make use of steam pressure instead of a pump in order to brew espresso capsule machine. The drawback is that the same boiler that produces steam also increases the temperature of water until it reaches boiling and can result in excessive extraction. Additionally, these machines frequently have to rebuild their pressure between cups, which takes time and energy.

A majority of espresso machines utilize a rotary or vibration pump. A vibration model utilizes a vibrating disk to generate pressure, whereas the circular model pushes hot liquid through the ground at a high speed. Both machines can make great espresso, however rotary machines are more stable, quieter and less likely bean to cup espresso machine break.

The Boiler

The boiler is what heats the water to the perfect temperature for extraction. The steam that is produced reaches the portafilter which holds the ground espresso coffee, and is then funneled down into the cup. The steam is able to create enough pressure to push the grounds of the coffee through. This creates a layer crema that is then poured over. This is one of the main characteristics of a good espresso.

There are three distinct types of espresso machines, each having different pumps and brew temperature. There are a variety of ways to control the brew and the size of the cup that can be produced by the machine.

The first espresso machines were steam-types. They used one boiler to create both brew and steam, however, the pressure they could 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 manufacturers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.

The most commonly used espresso machine is a semiautomatic model with an electric pump. These are what people imagine when they think of an espresso maker. Semi-automatic machines require you to grind and tamp the beans on your own, but the pump regulates the water flow and pressure. This is an excellent compromise between human touch and the mechanized quality.

The Filter

Typically, italian espresso machine machines utilize filters to separate the grounds of coffee when they pass through the hot water. The filter is also a vital element of the machine's temperature control, as it prevents overheating.

Filters also aid in flavor as it allows for a longer flowering phase. This helps the beans to release their flavor and gives an opportunity to improve extraction.

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

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

In the steam-driven espresso machine hot water is heated in an airtight container to create steam. This is then pushed through the grounds with high pressure. They are less expensive and easier to maintain than pumps-driven models. They are however limited in their ability to create the perfect conditions for brewing as they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

In recent years, espresso machines powered by a compressed air compressor have become increasingly popular. They utilize an air compressor to push hot water into the grounds and are more portable than electric steam-driven machines.