A Provocative Remark About Machine Espresso > 자유게시판

How Does Machine Espresso Work?

The machine espresso is made using precision pressure, and a filtering system that is awe-inspiring to create the coffee you enjoy. What exactly does it work?

espresso machine with grinder is made by pushing hot water under high 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 disperses water into the portafilter, and then regulates the pressure during the extraction. There are many different types of group heads each with their own advantages and disadvantages. Some are designed to provide stability in temperature, while others are specifically designed to handle pre-infusion. Some are designed to control the lever. There are even some that include a mix of features, such as the E61, which is the most popular choice among baristas because of its ability to offer multiple benefits in a single package.

As you can see in the above image, the group head has several notches where you place your portafilter and twist it manually to lock it in. A rubber gasket is located in the notches to create a seal when you insert your portafilter. The notches on the head permit a precise positioning of the portafilter which is essential to ensure an efficient extraction.

Aside from allowing you to easily connect your portafilter, the group head is also responsible for maintaining an even temperature. It does this by circulating hot water through the brew basket, and around the portafilter, ensuring that it is always at the correct temperature for extraction. It is crucial to keep in mind that even a few degree differences can make the distinction between a great and a excellent espresso.

The Pump

Unlike manual piston machines, which use a lever to pressurize water, rotary espresso machines rely on motorized pumps to deliver the nine atmospheric bars of pressure necessary to extract espresso. This pressure is built up by pumping water through a heat exchanger and then through the ground coffee.

Pumps are generally less expensive than piston-driven machines and tend to last longer. However, both types of machine can become damaged due to excessive use and poor cleaning. Pumps are also more complicated mechanically, and can add to the cost of even simple models.

Certain espresso machines utilize steam pressure instead of a pump for brewing espresso. The drawback of this is that the boiler that produces steam also raises the temperature of the water to the point of boiling, which can lead to over-extraction. These machines also have to constantly rebuild their pressure between cups. This takes energy and time.

Many espresso machines utilize the rotary or vibration pump, with a vibrating model using a vibrating disc to generate the pressure and an rotary model that pushes hot water through the grounds under high speed. Both models can produce an excellent espresso, however Rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is what will heat the water to the ideal temperature for extraction. The resulting steam is then transferred to the portafilter containing the ground espresso coffee, and is then pumped down into the cup. The steam causes enough pressure to push the grounds of the coffee through. This produces a layer of crema on top. This is one of the hallmarks of a good espresso machine black friday.

There are three distinct types of espresso machines, each having distinct pumps and brew temperature. There are different 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 employed one boiler to make steam and brew, however, the pressure they could produce was very low - just two bars of atmospheric pressure at most. This led to the coffee tasting bitter and burnt. The modern espresso machine was designed by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most well-known espresso maker is a semi-automatic machine with an electric pump. When people think of professional espresso machine for home machines, they imagine these machines. Semi-automatic machines require you to grind and tamp your beans yourself The pump, however, regulates the water flow and pressure. This is an excellent compromise between human control and mechanised accuracy.

The Filter

Typically, espresso machines have filters to separate the grounds of the coffee as they go through the hot water. The filter is also an important part of the temperature control system as it prevents the machine from overheating.

It also improves flavor, as a filter allows for a longer bloom time. This helps the beans to let their nuances out and provides the chance for better extraction.

It is important to remember that even the most efficient filter can produce a bad cup of coffee. The quality of the beans and the extraction process remain crucial.

This is where the magic happens, it's what makes an espresso really taste great. The grouphead, sometimes called the brew head, is where the portafilter (the thingy you put the ground coffee into) is placed when you're making espresso.

In a 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 are easier for the user to maintain than pumps-driven models. However, they are not as efficient in their ability to create the perfect brewing conditions because they operate at 1-1.5 bars of pressure. While the perfect shot requires 9-10 bar.

In recent years, compressed-air-pump-driven retro espresso machine machines have become more popular. They use an air-compressor to force hot water through the ground. They are also more mobile than electric steam-driven espresso machines.