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

How Does Machine Espresso Work?

Machine espresso makes use of precise pressure and incredible filter technology to produce the coffee we love. What exactly does it work?

Espresso is made by forcing hot water at 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

The group head is the portafilter that you place in the espresso maker when making it. It disperses the water into the portafilter, and then regulates the pressure of extraction. There are a variety of types of group heads, each with their particular advantages and disadvantages. Some are designed for stability of temperature while others are specifically designed to handle pre-infusion. Others are made to control the lever. There are even some that include a mix of features, like the E61, which is the classic choice among many baristas due to its ability to offer multiple benefits in a single package.

As you can see in the above photo the group head comes with several notches where you place your portafilter before twisting it manually to lock it in. There is also a gasket made from rubber which is located inside the notches and helps to create a seal when you insert your portafilter into the machine. The notches on the head allow for a precise placement 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 an even temperature. This is achieved by cycling hot water around the portafilter, and through the brew-basket, ensuring that the temperature is at the right level to extract the coffee. It is important to note that even a few degree differences can make the distinction between a great and a great espresso.

The Pump

Unlike manual piston machines, that use a lever to pressurize water, Rotary espresso machines rely on motorized pumps to provide the nine atmospheric bars of pressure that are required to extract espresso. This pressure builds up by drawing tap water from a reservoir and pumping it through a heat exchanger prior being pumped through the ground coffee inside 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 insufficient cleaning. Pumps are also more complicated mechanically, which could increase the cost of even most basic models.

Some espresso machines do away with the pump completely and instead use steam pressure to brew espresso. The downside is that the boiler that produces steam also raises the temperature of the water to boiling and can result in over-extraction. In addition, these machines frequently have to rebuild their pressure between cups, which requires time and energy.

A large majority of espresso machines employ either a vibration or rotary pump. A vibration model makes use of the vibrating disk to create pressure, while the rotating model pushes hot water through the ground at a rapid speed. Both machines can make great espresso but rotary machines are quieter, more durable and less likely to fail.

The Boiler

The boiler is the element that heats water to an optimal temperature for extraction. The resulting steam reaches the portafilter which holds ground espresso beans and is then pumped down into the cup. In this process, the steam creates pressure to push through the grounds of the coffee. This creates a layer crema on top. This is the hallmark of a good espresso.

There are three types of espresso makers. They differ in the kind of pump they use and how hot the espresso is. There are also different ways that the brew can be controlled as well as the dimensions of the cup the machine can produce.

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

The most well-known espresso maker is a semi-automatic one that has an electric pump. These are the images people have when they imagine an espresso machine. With a semi-automatic machine you must grind the beans and tamp them by hand, but the pump is able to regulate the flow of water and pressure. This is a fantastic combination of human control and mechanized accuracy.

The Filter

Typically, espresso machines utilize filters that separate the grounds of coffee when they pass through the hot water. The filter is also a crucial component of the temperature control system, as it prevents the machine from overheating.

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

It is important to keep in mind that even the most efficient filter can result in a bad cup of coffee. The quality of the beans, and the extraction process, remain crucial.

It's in this area that the magic happens. This is the reason why espresso tastes so delicious. The grouphead (also called the brewhead) is where you put the portafilter - the thingy which you put the coffee grounds into, while making travel espresso maker.

In the steam-driven espresso machine hot water is heated in an airtight container to create steam, which is then pushed through the grounds at a high pressure. These machines are cheaper and easier for the owner to maintain than pumps-driven models. However, they are limited in their ability to produce the ideal brewing conditions, as they only operate 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 make use of an air compressor to push hot water across the ground and are more mobile than electric steam-driven espresso machines.