20 Questions You Should Have To Ask About Machine Espresso Before Purchasing It > 자유게시판

How Does Machine Espresso Work?

Machine espresso uses precision pressure and mind-blowing filter technology to create the delicious coffee we enjoy. How exactly does it work?

Espresso is created by forcing hot water under pressure through finely ground coffee. The process is similar to making drip coffee but the key difference is in the pressure.

The Head of the Group

The group head is the portafilter that is inserted when you are making Travel Espresso maker. It disperses water in the portafilter, and regulates the pressure during the extraction. There are numerous kinds of group heads each with distinct advantages and drawbacks. Some are focused on temperature stability, whereas others on pre-infusion capabilities, and still others are designed to control the lever. There are even some that come with a range of features, such as the E61 one, which is the standard choice for many baristas due to its ability to offer multiple benefits in one package.

As you can see in the image above The group head features numerous notches that you can place your portafilter and then twist it manually to secure it. A gasket made of rubber is positioned in the notches to make a seal when you insert your portafilter. The notches on the head allow for an exact positioning of the portafilter which is necessary to ensure an even extraction.

The group head not only lets 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 basin, ensuring that the temperature is always at the right level to extract the coffee espresso machine. This is crucial, since even a small difference in temperature can make the difference between a excellent and great espresso.

The Pump

The motorized pumps in rotary espresso machines supply the nine atmospheric bar pressure required to extract espresso. This differs from manual piston machines that rely on a lever. This pressure builds up by drawing 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 are generally less expensive than piston-driven models, and they tend to last longer, but both types of machines may become damaged due to excessive use and poor cleaning. Pumps are also more complex mechanically, and can add bean to cup espresso machines the cost of even most basic models.

Some espresso machines use steam pressure instead of a pump to brew espresso. This can result in over-extraction because the boiler that produces steam also warms the water to boil. The machines must also constantly rebuild their pressure between cups. This requires energy and time.

Many espresso machines make use of an rotary or vibrating pump, which has a vibration model that uses a vibrating disc to create the pressure and rotating models that push hot water through the grounds at high speed. Both types of machine are capable of producing excellent espresso, but Rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the component that heats water to the ideal temperature to extract. The resultant steam then reaches the portafilter which holds the ground espresso coffee espresso machine, and gets funnelled down into the cup. The steam is able to create enough pressure to push the grounds of coffee through. This creates a crema on the top of the espresso. This is one of the main characteristics of a great espresso.

There are three kinds of espresso machines, each having different pumps and the temperature of the brew. There are also different ways in which the brew could be controlled as well as the size of the cup the maker can create.

The first espresso machines were steam type. They used a single boiler to make steam and brew, but the pressure they could produce was very low - just two bars of atmospheric pressure maximum. The coffee tasted bitter and burned. The modern espresso machine was invented by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most popular espresso maker is a semi-automatic machine that has an electric pump. When people think of espresso machines, they picture these machines. Semi-automatic machines require you to grind and tamp the beans yourself however the pump controls the flow of water and pressure. This is an excellent compromise between human touch and mechanized quality.

The Filter

Espresso machines typically have filters that separate the grounds of coffee from hot water. The filter is also an essential part of the temperature control system, as it keeps the machine from overheating.

It also helps with flavor, as a filter can allow for a longer bloom phase. This helps the beans to let their nuances out and provides an opportunity to improve extraction.

However, it is important to remember that even a high-quality filter can produce a bad cup of coffee, since the quality of the beans and extraction is vital.

This is where the magic happens, it's the thing that makes espresso taste good. The grouphead (also known as the brewhead) is where you place the portafilter, which is the thingy that you put the grounds of coffee into when making espresso.

Steam-driven espresso machines make use of hot water that is heated inside an airtight container to produce steam. The steam then pushes hot water through the grounds of coffee under high pressure. These types of machines are generally less expensive and easier to maintain than pumps-driven models. They are however limited for creating the ideal brewing conditions as they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

In recent times, compact espresso machine machines powered by compressed air-pump have become increasingly popular. They utilize an air compressor to force hot water through the grounds and are significantly more portable than electric steam-driven machines.