10 Quick Tips About Machine Espresso > 자유게시판

How Does Machine Espresso Work?

Machine espresso uses precision pressure and amazing filter technology to make the coffee we love. What exactly does it work?

Espresso is made by forcing hot water under high pressure through finely-ground coffee. The process is similar to making drip coffee, however the main difference lies 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 a variety of group heads each with its own advantages and disadvantages. Some are designed for stability of temperature while others are designed to handle pre-infusion. Others are built to control the lever. Some come with a combination of both, like the E61. This is a popular choice among baristas because it offers multiple advantages in one package.

As you can see from the photo above the head of the group has a number of notches. The portafilter is placed in these notches and then turn the head around to secure it. A gasket made of rubber is positioned inside the notches, which helps create a seal when you insert your portafilter. The notches on the head permit an exact placement of the portafilter, which is crucial for an efficient extraction.

Aside from allowing you to easily insert your portafilter, the group head is also responsible to ensure that the temperature remains even. It does this by cycling hot water through the brew basket, and around the portafilter, making sure that it's always at the right temperature for extraction. This is important, espresso coffee Machine home as just a few degrees could mean the difference between good and great Espresso Coffee Machine Home.

The Pump

In contrast to piston machines that are manually operated, that use a lever to pressurize water, the rotary espresso machines use motorized pumps to supply the nine atmospheric bars of pressure necessary for espresso extraction. This pressure is built up by pumping water through a heat exchanger and then through the ground coffee and espresso machine.

Pumps tend to be cheaper than piston-driven models, and they tend to last longer, however both types of machines could be damaged by excessive use and inadequate cleaning. They also increase the complexity of mechanical systems and can lead to an expensive price for even the simplest models.

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

Many espresso machines make use of a rotary or vibration pump. A vibration model makes use of a vibrating disk to generate pressure, while a Rotary model pushes hot coffee through the ground at a fast speed. Both machines can make great espresso, however rotary machines are more quiet, durable and less likely to break.

The Boiler

The boiler is the part that heats the water to the optimal temperature for extraction. The resulting steam is then transferred to the portafilter which holds ground espresso beans and gets funnelled down into the cup. The steam causes enough pressure to push the coffee grounds through. This creates a foam on top of the espresso. This is the hallmark of a great espresso.

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

The earliest espresso machines were steam types. They employed only one boiler to make both steam and brew, but the pressure they could create was minimal - two bars of atmospheric pressure, at most. The coffee tasted bitter and burned. The modern espresso machine was created by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most well-known espresso machine is a semiautomatic model with an electric pump. When people think of espresso machines, they envision these machines. With a semi-automatic machine, you need to grind the beans and then tamp them by hand. The pump regulates the flow of water and pressure. This is a perfect compromise between human control and mechanised reliability.

The Filter

Typically, espresso machines use filters that separate the coffee grounds as they pass through the hot water. The filter is also an important element of the temperature control system as it prevents the machine from overheating.

Filters also aid in flavor, as it permits an extended flowering time. This allows the beans to release their flavors, and improves extraction.

It is important to remember that even the most efficient filter could result in a poor cup of coffee. The quality of the beans, and the extraction, remain crucial.

It's here that the magic occurs. This is what makes espresso taste so good. The grouphead (also known as the brewhead) is where you place the portafilter - the thingy that you put the coffee grounds in, when making best home espresso machine.

In the steam-driven espresso machine hot water is heated in an airtight tank to create steam. Steam is then pushed through the grounds at high pressure. They are less expensive and easier to maintain than pumps-driven models. They are however limited in their ability for creating the ideal conditions for brewing, as they operate with 1-1.5 bar of pressure. The ideal shot requires 9-10 bars.

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