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

How Does Machine Espresso Work?

Machine espresso uses precision pressure and mind-blowing filter technology to create the perfect cup of coffee. How does it work exactly?

Espresso is made by forcing hot water under high pressure through finely-ground coffee. The process is similar to making drip coffee. However the pressure is the major difference.

The Group Head

As the name suggests, the group head is the place you insert your portafilter when brewing espresso. It distributes water into the portafilter, and then regulates the pressure during the extraction. There are a variety of types of group head, each with their unique advantages and disadvantages. Some focus on temperature stability, some on pre-infusion features, and others are designed to control the lever. Some include a combination like the E61. This is a preferred choice for baristas since it provides multiple benefits in one package.

As you can see from the photo above, the group head has a number of notches. You place your portafilter into these notches and twist the head to lock it. There is also a gasket of rubber in the notches and helps to create a seal when you insert your portafilter into the machine. The notches allow for an exact placement of the portafilter. This is crucial for a consistent extraction.

The group head is not just able to allow the portafilter to be inserted easily however, it also keeps the temperature at a constant level. 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 note that even a slight variation can mean the difference between a Decent Espresso Machine and a great espresso.

The Pump

In contrast to piston machines that are manually operated, which rely on a lever that pressurize water, rotating espresso machines rely upon motorized pumps to deliver the nine atmospheric bars of pressure necessary to extract espresso. The pressure is created by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are generally more affordable and last longer than piston-driven machines. However, both types of machines can deteriorate because of excessive use and poor cleaning. Pumps are also more complicated mechanically, and can add to the cost of even the simplest models.

Certain espresso machines do away with the pump entirely and make use of steam pressure to make espresso. This can lead to over-extraction as the boiler that produces steam also heats the water until it comes to a boil. In addition, these machines frequently have to rebuild their pressure between cups, which takes time and energy.

Many espresso machines utilize either a rotary or vibration pump, with a vibration model using a vibrating disc to create pressure and a rotary model pushing hot water through the grounds under high speed. Both models can make excellent espresso, however rotary machines espresso are quieter and more durable than vibration pumps.

The Boiler

The boiler is the element that heats the water to the ideal temperature for extraction. The resulting steam reaches the portafilter containing the ground espresso coffee and is then pumped down into the cup. During this process the steam causes enough pressure to push the coffee grounds through. This results in a layer crema on top espresso machines. This is the hallmark of a great espresso.

There are three kinds of espresso makers. They differ in the type of pump they employ and the degree of heat that the brew is. There are a variety of ways in which the brew can be controlled, as well as the size of the cup the machine can produce.

The first espresso machines were steam types. They used one boiler to make both steam and brew but the pressure they could produce was very low - just two bars of atmospheric pressure at the most. The coffee tasted bitter and burnt. The modern best espresso maker machine was developed by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso maker is a semi-automatic machine that has an electric pump. When people think of espresso machines, they envision these machines. If you have a semi-automatic machine you have to grind the beans and tamp them by hand. However, the pump controls the flow of water and pressure. This is a great compromise between the human touch and mechanized quality.

The Filter

Typically, espresso machines have filters that separate the grounds of coffee as they move through the hot water. The filter is also an essential component of the machine's temperature control, since it helps to prevent overheating.

It also improves flavor, as a filter lets you enjoy a longer bloom phase. This helps the beans release their nuances and gives the chance for better extraction.

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

It's here that the magic takes place. This is what makes espresso taste so delicious. The grouphead (also known as the brewhead) is where you place the portafilter, the thingy that you use to put the grounds of coffee into when making espresso.

Steam-driven espresso machines use hot water that is heated in an airtight vessel to create steam. The steam then moves hot water through the grounds of the coffee under pressure. These machines are cheaper and easier for the owner 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, espresso machines driven by compressed air-pump have become increasingly popular. They use an air compressor to force hot water through the ground and are much more mobile than electric steam-driven espresso machines.