9 Lessons Your Parents Teach You About Machine Espresso > 자유게시판

How Does Machine Espresso Work?

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

To make espresso, hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee. However, it is the pressure that makes the main difference.

The Head of the Group

As the name suggests, the group head is the place you place your portafilter while making espresso. It is responsible for dispersing water into the portafilter and then controlling the pressure of the resulting extraction. There are a variety of group heads each with its own advantages and drawbacks. Some are designed to provide temperature stability while others are specifically designed to handle pre-infusion. Others are built to control the lever. There are even some that have a combination of features, like the E61, which is considered the standard choice for many baristas for its ability to offer multiple benefits in a single package.

As you can see from the above photo, the group head is fitted with several notches. You place your portafilter inside these notches, and then turn the head around to secure it. A gasket made of rubber is placed within the notches to create a seal as you insert your portafilter. The notches permit precise placement of your portafilter. This is crucial for an even extraction.

The group head not only lets the portafilter to be inserted easily however it also keeps an even temperature. It does this by circulating hot water through the brew pan and around the portafilter, ensuring that it is always at the right temperature for extraction. It is important to remember that even a small differences can make the distinction between a good and excellent espresso.

The Pump

The motorized pumps used in rotary espresso machines provide the nine atmospheric bar pressure needed for espresso extraction. This differs from manual piston machines that use a lever. The pressure is created by removing tap water from a reservoir and pumping it through a heat exchanger prior to being shot through the ground coffee in the group head.

Pumps tend to be cheaper than piston-driven models, and they tend to last longer, although both types of machines may get damaged through overuse and lack of cleaning. Pumps are also more complex mechanically, which can increase the cost of even simple models.

Some espresso machines use steam pressure instead of a pump in order to brew espresso. The disadvantage of this is that the boiler that produces steam also raises the temperature of water until it reaches boiling which could lead to over-extraction. The machines also need to continually rebuild their pressure between cups. This takes energy and time.

A majority of espresso maker for home machines utilize either a vibration or rotary pump. A vibration model employs an oscillating disk to create pressure, while a rotating model pushes hot water through the ground at a rapid speed. Both machines can produce excellent espresso but rotary machines are quieter, more durable and less likely to break down.

The Boiler

The boiler is what makes the water warm to the right temperature for extraction. The resulting steam is then transferred to the portafilter containing the ground espresso coffee, and is then funneled down into the cup. During this process, the steam causes pressure to push through the coffee grounds. This produces a layer of crema that is then poured over. This is one of the main characteristics of a good espresso.

There are three kinds of espresso makers. They differ in the type of pump they use and the degree of heat that the espresso is. There are many ways to control the brew as well as the size of the cup that can be produced by the machine.

The first espresso coffee machine home machines were steam-based. They used one boiler to create both steam and brew, however the pressure they were able to produce was very low - just two bars of atmospheric pressure at the most. The coffee tasted bitter and burned. The modern espresso machine was developed by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso machine sale machine is a semiautomatic with an electric pump. These are the things people think of when they think of an espresso maker. Semi-automatic espresso machine machines require you to grind and tamp the beans on your own however the pump controls the water flow and pressure. This is a fantastic combination of human control and mechanised accuracy.

The Filter

Typically, espresso machines employ filters that separate the grounds of coffee when they pass through the hot water. The filter is also a crucial component of the temperature control system, as it keeps the machine from overheating.

A filter can also help with flavor, as it permits a longer flowering period. This allows the beans to let their nuances out and provides an opportunity for better extraction.

However it is crucial to remember that even a great filter could result in a bad cup of coffee, since the quality of the beans and extraction are essential.

It's in this area that the magic occurs. This is the reason why espresso tastes so good. The grouphead (also called the brewhead) is where you put the portafilter, the thingy that you use to put the grounds of your coffee into when making espresso.

In a steam-driven espresso machine, hot water is heated in an airtight tank to create steam. This then pushes the hot water through the grounds at high pressure. These machines are cheaper and easier for the user to maintain than pumps-driven models. They are however limited in their ability 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, compressed air-pump-driven espresso machines have been gaining popularity. They utilize an air compressor to push hot water through the grounds and are much more portable than steam-driven electric machines.