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

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How Does Machine Espresso Work?

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

Espresso is created by forcing 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 you insert when brewing espresso. It distributes water into the portafilter, and regulates the pressure during the extraction. There are many different types of group heads each with their own advantages and disadvantages. Some are designed for stability in temperature, while others are specifically designed to handle pre-infusion. Others are built to control the lever. There are some that contain a variety of features, like the E61 that is the standard choice for many baristas because of its ability to provide multiple benefits in one package.

As you can see in the photo above The group head features many notches in which you can place your portafilter and twist it manually to secure it. There is also a gasket made of rubber that resides inside the notches and helps create an airtight seal after inserting your portafilter into the machine. The notches allow for precise placement of your portafilter. This is crucial for an accurate extraction.

Aside from allowing you to easily connect your portafilter, the group head is responsible for maintaining a consistent temperature. It does this by cycling hot water through the brew basket, and around the portafilter, ensuring that it's always at the correct temperature to extract. This is vital, because even a small difference in temperature can make the difference between a good and excellent espresso.

The Pump

The motorized pumps that are used in rotary espresso machines supply the nine atmospheric bars of pressure required for espresso extraction. This is different from manual piston machines that use levers. The pressure builds up by removing tap water from a reservoir, and pumping it through a heat exchanger prior it is shot through the ground coffee in the group head.

Pumps tend to be more affordable and last longer than piston-driven machines. However, both types of machines may degrade because of excessive use and poor cleaning. Pumps are also more complicated mechanically, which can increase the cost of even simple models.

Some mini espresso machine machines make use of steam pressure instead of a pump to brew mini espresso machine. This could lead to over-extraction since the boiler that produces steam also causes the water to boil. Additionally the machines often have to rebuild their pressure between cups, which requires time and energy.

Many espresso machines make use of an rotary or a vibration pump. A vibration model utilizes an oscillating disk to create pressure, while a circular model pushes hot liquid through the ground at a rapid speed. Both machines produce great espresso but rotary machines are more quiet, durable and less likely to fail.

The Boiler

The boiler will heat the water to the right temperature to extract. The steam that is created gets to the portafilter which contains the espresso coffee grounds. It is then funneled into the cup. The steam generates enough pressure to push the grounds of the coffee through. This creates a crema on the top of the espresso. This is one of the hallmarks of a great espresso.

There are three types of espresso machines, each having different types of pumps and the temperature of the brew. There are different ways to control the brew and the size of cup that can be produced by the machine.

The first espresso machines were steam types. They had one boiler to create both steam and brew, but the pressure they could produce was not very high - two bars of atmospheric pressure, at most. This resulted in the best coffee espresso machine tasting bitter and burnt. This is the reason Milanese makers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.

The most common espresso maker is a semi-automatic machine with an electric pump. When people think of espresso machines, they envision these machines. Semi-automatic machines require you to grind and tamp the beans by yourself while the pump controls the flow of water and pressure. This is a fantastic solution that combines human control with mechanised accuracy.

The Filter

Typically, espresso machines have a filter to separate out the grounds of coffee as they move through the 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 can allow for a longer bloom time. This lets the beans release their flavor and allows for better extraction.

However, it is important to keep in mind that even a high-quality filter can result in a poor cup of coffee as the quality of the beans and extraction are essential.

It's in this area that the magic occurs. This is what makes espresso taste so delicious. The grouphead, also referred to as the brew head, is where the portafilter (the container you place the coffee grounds into) is located when you're making espresso.

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

In recent years, barista espresso coffee machine machines driven by compressed air-pump are becoming increasingly popular. They make use of an air compressor to push hot water through the ground and are much more mobile than electric steam-driven espresso machines.