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

How Does Machine Espresso Work?

Machine espresso utilizes precise pressure and mind-blowing filter technology to create the coffee we love. But how exactly does it work?

Espresso is produced by pushing hot water under high pressure through finely ground coffee. The process is similar to that of making drip coffee. However, the pressure is the major difference.

The Group Head

As the name implies the group head is where you put your portafilter in when making espresso. It disperses water into the portafilter, and regulates the pressure of extraction. There are various kinds of group heads, each with their unique advantages and disadvantages. Some are designed to provide the stability of temperature while some are built to handle pre-infusion. Others are built to control the lever. Some contain a variety of features, like the E61 one, which is the classic choice among many baristas because of its ability to provide multiple benefits in a single package.

As you can see from the image above the head of the group is equipped with several notches. The portafilter is placed in these notches and then twist the head to secure it. There is also a rubber gasket that resides inside the notches, which helps create an airtight seal after inserting your portafilter into the machine. The notches permit the precise placement of the portafilter. This is essential for a consistent 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 to ensure that it is always at the right temperature for extraction. This is crucial, since even a small espresso machine difference in temperature can make the difference between excellent and great cheap espresso machine.

The Pump

The motorized pumps that are used in espresso machines rotary provide nine atmospheric bar pressure required for espresso extraction. This differs from manually operated piston machines that employ levers. The pressure is built by pumping water through a heat-exchanger and then through the ground coffee.

Pumps tend to be less expensive than piston-driven machines, and tend to last longer, but both types of machine can degrade with overuse and insufficient cleaning. They also increase the complexity of mechanical systems which can result in an expensive price for even the most basic models.

Certain espresso machines eliminate the pump entirely and make use of steam pressure to make espresso. The drawback 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. In addition these machines are often required to restore their pressure between cups, which takes time and energy.

Many espresso machines make use of either a rotary or vibration pump, with a vibration model using a rotating disc to create pressure, and a rotary model pushing hot water through the grounds under high speed. Both machines can make great espresso however rotary machines tend to be quieter, more durable and less likely to break down.

The Boiler

The boiler is the component that heats water to the ideal temperature for extraction. The steam that is produced will eventually reach the portafilter, Machine Espresso which is a container for espresso grounds. It is then poured into the cup. During this process, the steam creates pressure that pushes through the coffee grounds. This creates a layer crema on top. This is a hallmark of a good espresso.

There are three distinct types of espresso machines, each with a different type of pump and brew temperature. There are different ways that the brew may be controlled as well as the size of the cup the machine can produce.

The first espresso machines were steam-type. They utilized only one boiler to make steam and brew, however, the pressure they could generate was low - only two bars of atmospheric pressure at the most. This resulted in the coffee tasting bitter and burnt. The modern espresso machine was invented by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

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

The Filter

Espresso machines usually have a filter that separates the grounds of the coffee from hot water. The filter is also a vital component of the temperature control system, since it helps prevent the machine from overheating.

It also improves flavor, as it allows for a longer bloom phase. This allows the beans to let their nuances out, and allows for better extraction.

It is important to remember that even the finest filter can produce a bad cup of coffee. The quality of the beans and the extraction process, are still crucial.

This is where the magic happens, it's the thing that makes espresso taste great. The grouphead, often called the brew head, is the place where the portafilter (the thing you put the coffee grounds into) sits when you're making espresso.

In a steam-driven espresso machine hot water is heated in an airtight container to create steam, which is then pushed through the grounds at high pressure. These kinds of machines tend to be cheaper and easier to maintain than pumps-driven models. However, they are limited in their capacity to create the ideal conditions for brewing since they are only operating at 1-1.5 bars of pressure, while 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 force hot water into the grounds and are significantly more portable than electric steam-driven machines.