• 글쓰기
• 목록

How Does Machine Espresso Work?

Machine espresso uses precision pressure and amazing filter technology to make the delicious coffee we enjoy. But 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 is inserted when you are making espresso maker barista. It disperses the water into the portafilter and controls the pressure of the extraction. There are a variety of types of group heads each with its unique advantages and disadvantages. Some focus on temperature stability, some on pre-infusion capabilities, and still others are designed to control the lever. Some include a combination such as the E61. This is a very popular choice for baristas since it provides multiple advantages in a single package.

As you can see in the above photo 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 rubber gasket that resides inside the notches and helps to create an airtight seal when you insert your portafilter into the machine. The notches allow for the precise placement of the portafilter. This is essential for an accurate extraction.

The group head not only lets the portafilter to be inserted easily but also maintains the same temperature. It does this by circulating hot water through the brew container and around the portafilter, making sure that it is always at the right temperature to extract. It is important to realize that even a slight difference can make the difference between a decent espresso machine and a great espresso.

The Pump

Motorized pumps in rotary espresso machines supply the nine atmospheric bars of pressure required to extract espresso. This is different from manual piston machines that use levers. This pressure builds up by drawing tap water from a reservoir, and pumping it through a heat exchanger prior to being pumped through the ground coffee in the group head.

Pumps are generally less expensive than piston-driven machines, and tend to last longer. However, both types of machine can degrade with overuse and insufficient cleaning. They also add mechanical complexity, which can result in costly prices for even the most basic models.

Certain espresso machines can eliminate the pump completely and instead employ steam pressure to create barista espresso machine. The drawback is that the same boiler that produces steam also increases the temperature of the water to the point of boiling and can result in excessive extraction. They also have to constantly rebuild their pressure in between cups. This requires energy and time.

Many espresso machines use an rotary or a vibration pump. A vibration model employs the vibrating disk to create pressure, whereas the rotating model pushes hot water through the ground at a rapid speed. Both types of machine can produce an excellent espresso, but Rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the element that heats water to the ideal temperature for extraction. The steam that is created gets to the portafilter which holds the espresso grounds. The steam is then channeled into the cup. In this process, the steam creates pressure that pushes through the coffee grounds. This results in a whipped-up the top of the espresso. This is the hallmark of a good espresso.

There are three distinct types of espresso machines, each with distinct pumps and the temperature of the brew. There are various ways to control the brew as well as the size of the cup that can be made by the machine.

The first espresso machines were steam-type. They used only one boiler to make both steam and brew however the pressure they were able to generate was low - only two bars of atmospheric pressure at most. The coffee tasted bitter and burnt. The modern buy espresso makers machine was developed by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most popular espresso machine is a semiautomatic with an electric pump. When people think of espresso machines, they imagine 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 a great compromise between the human touch and the mechanized consistency.

The Filter

Typically, espresso machines use filters that separate 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.

It also aids in flavor as a filter allows for a longer bloom time. This lets the beans let their nuances out, and allows for a better extraction.

It is important to keep in mind that even the most efficient filter can result in a bad cup of coffee. The quality of the beans as well as the extraction, are still very important.

This is where the magic happens, it's the thing that makes espresso taste great. The grouphead, sometimes called the brew head, is the place where the portafilter (the thingy you put the ground coffee in) is placed when making espresso.

In a steam-driven espresso machine, hot water is heated in an airtight tank to create steam, which is then pushed through the grounds with high pressure. These kinds of machines are typically less expensive and simpler to maintain than pump-driven models. However, they are not as efficient in their ability to produce the perfect brewing conditions as they only operate at 1-1.5 bars of pressure. However, the perfect shot requires 9-10 bar.

In recent years, compressed air-driven espresso machines have become more popular. They use an air compressor to push hot water through the grounds, and are far more portable than steam-driven electric machines.