9 . What Your Parents Teach You About Machine Espresso > 자유게시판

How Does Machine Espresso Work?

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

Espresso is made by pushing hot water at high pressure through finely-ground coffee. The process is similar to making drip coffee. However the pressure is the primary difference.

The Group Head

The group head is the portafilter that you put in when making espresso. It disperses the water into the portafilter and regulates the pressure during the extraction. There are many different types of group heads, each with its own advantages and drawbacks. Some are focused on temperature stability, others on pre-infusion features, and others are designed to control the lever. There are also some that come with a range of features, like the E61 that is the standard choice for many baristas because of its ability to provide multiple benefits in a single package.

As you can see in the above photo the group head is made up of many notches in which you can place your portafilter and then twist it by hand to secure it. A rubber gasket is located within the notches to create a seal as you insert your portafilter. The notches on the head permit an exact positioning of the portafilter which is essential for an even extraction.

In addition to allowing you effortlessly insert your portafilter the group head is also responsible for maintaining an even temperature. 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. It is important to note that even a small variation can mean the difference between a decent and a excellent espresso.

The Pump

The motorized pumps that are used in espresso machines rotary provide nine atmospheric bar pressure required for espresso extraction. This is different from manual piston machines that rely on levers. The pressure is created by removing tap water from a reservoir, and pumping it through a heat exchanger before being pushed through the ground coffee in the group head.

Pumps are typically less expensive than piston-driven machines, and tend to last longer, but both types of machine can get damaged through overuse and lack of cleaning. They also add mechanical complexity which can result in a high price tag on even the most basic models.

Some espresso machines use steam pressure instead of a pump to make buy espresso machine. This can cause over-extraction because the boiler that produces steam also causes the water to boil. In addition these machines typically have to rebuild their pressure between cups, which takes time and energy.

A majority of espresso machines utilize a rotary or vibration pump. A vibration model makes use of an oscillating disk to create pressure, while the rotary model pushes hot water through the ground at a rapid speed. Both machines can produce excellent espresso however rotary machines tend to be more quiet, durable and less likely to fail.

The Boiler

The boiler makes the water warm to a temperature that is ideal to extract. The resultant steam then reaches the portafilter that contains ground espresso beans and is then pumped into the cup. During this process the steam is able to create enough pressure to push the grounds of the coffee through. This results in a layer crema on top. This is one of the hallmarks of a good espresso.

There are three kinds of best espresso machine makers, and they differ in the type of pump they use and the degree of heat that the coffee is. There are different ways in which the brew can be controlled as well as the size of the cup the machine can make.

The first barista espresso machine machines were steam-types. The earliest espresso machines were steam types. The coffee tasted bitter and burnt. The modern espresso machine was invented by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used cafe espresso machine machine is a semiautomatic with an electric pump. These are what people imagine when they think of an espresso machine. Semi-automatic machines require you to grind and tamp your beans yourself however the pump controls the water flow and pressure. This is an excellent solution that combines human control with mechanised reliability.

The Filter

Typically, espresso machines employ a filter to separate out the grounds of coffee as they move through the hot water. The filter is also a crucial part of the temperature control system, as it keeps the machine from overheating.

A filter also helps with flavor because it allows for a longer flowering period. This lets the beans release their flavors, and improves extraction.

It is important to keep in mind that even the finest filter could result in a poor cup of coffee. The quality of the beans, and the extraction process remain crucial.

It's here that the magic takes place. This is the reason why espresso tastes so good. The grouphead, sometimes referred to as the brew head, is where the portafilter (the thing you put the ground coffee in) is placed when you're making espresso.

In a steam-driven espresso machine, hot water is heated in an airtight container to create steam. Steam is then pushed through the grounds with high pressure. These kinds of machines tend to be less expensive and simpler to maintain than pumps-driven models. However, they are limited in their ability to provide the ideal brewing conditions, since they are only operating at 1-1.5 bars of pressure. The perfect shot requires 9-10 bars.

In recent years, espresso machines powered by a compressed air compressor have become increasingly popular. They use an air compressor to push the hot water through the grounds and are more portable than electric steam-driven machines.