12 Facts About Machine Espresso To Bring You Up To Speed The Cooler. Cooler > 자유게시판

How Does Machine Espresso Work?

Machine espresso utilizes precise pressure and mind-blowing filter technology to create the perfect cup of coffee. What exactly does it work?

To make espresso capsule machine hot water is forced under high pressure through finely ground coffee machines espresso. The process is similar to making drip coffee but the major difference is in the pressure.

The Head of the Group

The group head is the portafilter you put in when making espresso. It distributes water into the portafilter, and controls the pressure of the extraction. There are many different kinds of group head each with its particular advantages and disadvantages. Some are designed for stability in temperature, while others are specifically designed to handle pre-infusion. Others are made to control the lever. Some are a combination, like the E61. This is a favorite among baristas because it offers multiple advantages in one package.

As you can see in the photo above the group head comes with several notches to place your portafilter before twisting it by hand to lock it in. There is also a gasket of rubber in the notches and helps create an airtight seal when you insert your portafilter into the machine. The notches on the head allow for a precise placement of the portafilter, which is essential to ensure a consistent extraction.

Aside from allowing you to easily connect your portafilter, the group head is also responsible for maintaining an even temperature. This is accomplished by cycling hot water around the portafilter, and through the brew-basket, ensuring that the temperature is always at the right level for extraction. This is crucial, since even a best small espresso machine difference in temperature can make the difference between excellent and great espresso.

The Pump

Contrary to manual piston machines which use a lever to pressurize water, rotating espresso machines rely upon motorized pumps to provide the nine atmospheric bars of pressure needed to extract espresso. This pressure is built up by pumping water through a heat exchanger and then through the ground coffee.

Pumps tend to be less expensive than piston-driven machines, and they tend to last longer. However, both types of machines can degrade with overuse and insufficient cleaning. They also add mechanical complexity and can lead to a high price tag on even the simplest models.

Certain espresso machines can eliminate the pump entirely and employ steam pressure to create espresso. The disadvantage of this is that the same boiler that produces steam also raises the temperature of the water until it reaches boiling which can cause excessive extraction. They also have to continually rebuild their pressure between cups. This requires energy and time.

A large majority of espresso machines employ a rotary or vibration pump. A vibration model uses the vibrating disk to create pressure, whereas a rotary model pushes hot water through the ground at a rapid speed. Both machines produce great espresso however rotary machines tend to be quieter, more durable and less likely to break down.

The Boiler

The boiler is the one that is used to heat the water to the right temperature to extract. The resultant steam then reaches the portafilter which holds the ground espresso machine with grinder and gets funnelled down into the cup. During this process the steam is able to create enough pressure to push the grounds of the coffee through. This produces a layer of crema that is then poured over. This is a hallmark of a great espresso.

There are three types of espresso makers. They differ in the kind of pump they use and the degree of heat that the espresso is. There are different ways that the brew can be controlled and the dimensions of the cup the machine can produce.

The first espresso machines were steam type. They employed one boiler to make steam and brew, however the pressure they were able to produce was very low - just two bars of atmospheric pressure at the most. This resulted in the coffee tasting bitter and burnt. This is why the Milanese producers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.

The most popular espresso maker is a semiautomatic machine that has an electric pump. These are the images people have when they think of an espresso machine. Semi-automatic machines require you to grind and tamp the beans on your own, but the pump regulates the water flow and pressure. This is a great compromise between the human touch and the mechanised accuracy.

The Filter

Espresso machines usually use a filter that separates the grounds of the coffee from the hot water. The filter is also a vital element of the machine's temperature control, as it prevents overheating.

It also helps with flavor, since a filter allows for a longer bloom phase. This allows the beans to release their nuances and gives an opportunity for better extraction.

It is important to keep in mind that even the finest filter can make a bad cup of coffee. The quality of the beans and the extraction, remain vital.

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

In an espresso machine that is driven by steam, hot water is heated in an airtight tank to create steam. Steam is then pushed through the grounds under high pressure. These machines are less expensive and easier for the user to maintain than pumps-driven models. However, they are limited in their capacity to create the perfect conditions for brewing, since they operate at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bars.

In recent years, espresso machines driven by a compressed air compressor have become increasingly popular. They utilize an air compressor to force hot water through the ground and are more mobile than steam-driven electric espresso machines.