Nine Things That Your Parent Taught You About Machine Espresso > 문의하기

How Does Machine Espresso Work?

Machine espresso uses precision pressure and mind-blowing filter technology to make the perfect cup of coffee. How exactly does it work?

Espresso is made by pushing hot water under pressure through finely-ground coffee. The process is similar to that of making drip coffee. However it is the pressure that makes the main difference.

The Group Head

The group head is the portafilter that is inserted when you are making espresso. It disperses the water into the portafilter and controls the pressure of the extraction. There are a variety of types of group head, each with their distinct advantages and disadvantages. Some are specifically designed for stability in temperature, while others are specifically designed to handle pre-infusion. Others are made to control the lever. Some include a combination such as the E61. This is a favorite among baristas as it provides a variety of advantages in one package.

As you can see in the photo above the group head is made up of several notches where you place your portafilter and then twist it manually to lock it in. A gasket made of rubber is placed inside the notches to help make a seal when you insert your portafilter. The notches on the head permit an exact location of the portafilter which is vital for a consistent extraction.

Aside from allowing you to easily connect your portafilter, the group head is also responsible for maintaining a consistent temperature. It does this by cycling hot water through the brew pan and around the portafilter to ensure that it is always at the right temperature for extraction. This is important, as even a small difference in temperature can be the difference between a good and great espresso.

The Pump

The motorized pumps used in rotary espresso machines provide the nine atmospheric bar pressure that is required to extract espresso. This is different from manually operated piston machines that employ a lever. The pressure is created by removing tap water from a reservoir, and pumping it through a heat exchanger prior to being pushed through the ground coffee in the group head.

Pumps are typically less expensive and last longer than piston-driven machines. However, both types of machines can deteriorate due to excessive use and insufficient cleaning. They also create mechanical complexity, which can result in the cost of even the most basic models.

Some espresso machines make use of steam pressure instead of a pump in order to brew espresso. The drawback of this is that the same boiler that produces steam also increases the temperature of the water to the point of boiling which can cause over-extraction. They also have to constantly rebuild their pressure in between cups. This requires energy and time.

Many espresso machines make use of a rotary or vibration pump. A vibration model utilizes the vibrating disk to create pressure, whereas a rotating model pushes hot water through the ground at a fast speed. Both machines can make excellent espresso but rotary machines are quieter, more durable and less likely to break down.

The Boiler

The boiler is the part that heats the water to the optimal temperature to extract. The resulting steam reaches the portafilter containing the ground espresso and is then pumped down into the cup. During this process the steam causes enough pressure to push the grounds of the coffee through. This results in a crema on the top of the espresso. This is the hallmark of a great espresso.

There are three types of espresso makers, which differ in the type of pump they employ and the degree of heat that the brew is. There are a variety of ways that the brew can be controlled and the size of the cup that the machine can produce.

The first espresso machines were steam-based. The earliest espresso machines were steam-type machines. This led to the coffee tasting burnt and bitter. The modern espresso machine was designed by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most popular espresso maker is a semiautomatic machine with an electric pump. These are the things people think of when they think of an espresso machine. Semi-automatic machines require you to grind and tamp the beans yourself The pump, however, regulates the flow of water and pressure. This is an excellent compromise between human touch and the mechanized consistency.

The Filter

Espresso machines usually use a filter that separates the grounds of the coffee from hot water. The filter is also an important component of the temperature control system because it stops the machine from overheating.

A filter also helps with flavor as it allows for the beans to flower for a longer period of time. This allows the beans to let their nuances out, and allows for a better extraction.

However, it is important to remember that even a top filter can make a terrible cup of coffee, as the quality of the beans and extraction are vital.

It's here that the magic happens. This is the reason why espresso tastes so good. The grouphead (also called the brewhead) is where you place the portafilter, the device used to place the coffee grounds into, while making espresso.

Steam-driven espresso machines use hot water that is heated in an airtight vessel to create steam. The steam then pushes hot water into the grounds of coffee at high end espresso machine pressure. These types of machines are usually cheaper and easier to maintain than pumps-driven models. However, they are limited in their ability to produce the ideal 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 use an air compressor to force hot water into the grounds, and are far more portable than electric steam-driven machines.