How To Explain Machine Espresso To A Five-Year-Old

How Does Machine Espresso Work?

Machine espresso utilizes precise pressure and mind-blowing filter technology to create the coffee we love. What exactly is it?

To make espresso, hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee espresso machines. However the pressure is the major difference.

The Group Head

The group head is the portafilter that you put in when making espresso. It disperses water into the portafilter, and then regulates the pressure of the extraction. There are several different types of group head each with its particular advantages and drawbacks. Some are designed for stability of temperature while others are designed to handle pre-infusion. Others are built to control the lever. Some have a combination of features, like the E61, which is considered to be the most popular among baristas because of its ability to offer multiple perks in a single package.

As you can see in the photo above the group head comes with several notches where you place your portafilter and twist it with your hands to secure it. There is also a gasket made of rubber in the notches to help create an airtight seal when you insert your portafilter into the machine. The notches on the head permit a precise location of the portafilter which is necessary for an efficient extraction.

Aside from allowing you to easily insert your portafilter, the group head is responsible for maintaining a consistent temperature. This is accomplished by cycling hot water around the portafilter and through the brew-basket to ensure that the temperature is always at the right level to extract the coffee. It is important to remember that even a few degree difference can make the difference between a great and a great espresso.

The Pump

Contrary to manual piston machines which rely on a lever to pressurize water, rotary espresso machines rely on motorized pumps to deliver the nine atmospheric bars of pressure that are required to extract espresso. This pressure is built up by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are generally less expensive than piston-driven models, and they tend to last longer, however both types of machines could degrade with overuse and insufficient cleaning. Pumps are also more complex mechanically, which could increase prices of even simple models.

Certain espresso machines utilize steam pressure instead of a pump to make espresso. The drawback of this is that the boiler that produces steam also raises the temperature of water to the point of boiling which can cause over-extraction. Additionally these machines are often required to restore their pressure between cups, which requires time and energy.

Many espresso machines make use of an rotary or vibrating pump, which has 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 produce great espresso however rotary machines tend to be more stable, quieter and less likely to break down.

The Boiler

The boiler makes the water warm to a temperature that is ideal to extract. The steam that is produced reaches the portafilter containing the ground espresso coffee and is then pumped down into the cup. The steam creates pressure to push through the coffee grounds. This produces a layer of crema on top. This is one of the main characteristics of a good espresso.

There are three kinds of espresso and filter coffee machine makers, which differ in the type of pump they use and the degree of heat that the espresso is. There are a variety of ways that the brew can be controlled and the size of the cup that the maker can create.

The first espresso machines were steam-based. The first espresso machines were steam-type machines. The coffee tasted bitter and burnt. The modern espresso machine was created by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.

The most common espresso maker is a semiautomatic machine that has an electric pump. These are the things people think of when they imagine an espresso machine. Semi-automatic machines require you to grind and tamp your beans yourself while the pump controls the flow of water and pressure. This is a great compromise between the human touch and the mechanized quality.

The Filter

Espresso machines usually use a filter that separates the grounds of coffee for espresso machine from hot water. The filter is also an essential element of the machine's temperature control, since it stops overheating.

A filter also improves flavor since it allows for the beans to flower for a longer period of time. This lets the beans release their flavors, and allows for better extraction.

However, it is important to remember that even a good filter could result in a bad cup of coffee, because the quality of the beans and extraction is vital.

It's here that the magic happens. This is what makes espresso machine small (my response) taste so good. The grouphead, sometimes called the brew head, is where the portafilter (the thingy you put the ground coffee in) is located when you're making espresso.

Steam-driven espresso machines use hot water that is heated inside an airtight container to make steam. The steam then pushes hot water through the grounds of coffee at high pressure. These kinds of machines tend to be cheaper and easier to maintain than pumps-driven models. However, they are not as efficient in their capacity to create the perfect brewing conditions as they only operate at 1-1.5 bars of pressure. However, the perfect shot requires 9-10 bar.

In recent years, compressed air pump-driven espresso machines have been gaining popularity. They use an air-compressor to push hot water across the ground. They are also more mobile than steam-driven electric espresso machines espresso machines.