9 Lessons Your Parents Teach You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso uses precision pressure and amazing filter technology to make the coffee we love. What exactly does it work?

To make an espresso machine with milk frother hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee but the major difference is in the pressure.

The Head of the Group

The group head is the portafilter that you place in the espresso maker when making it. It is responsible for dispersing the water into the portafilter before controlling the pressure that results from the extraction. There are several different types of group heads each with its unique advantages and drawbacks. Some focus on temperature stability, while others on pre-infusion features, and others are designed to control the lever. There are also some that come with a range of features, like the E61, which is considered the most popular choice among baristas for its ability to offer multiple perks in a single package.

As you can see in the picture above, the group head is equipped with several notches. You can place your portafilter into these notches and turn the head around to secure it. A gasket of rubber is situated inside the notches to help make a seal when you insert your portafilter. The notches on the head permit a precise position of the portafilter which is necessary to ensure an even extraction.

In addition to allowing you easily connect your portafilter, the group head is responsible for maintaining an even temperature. It does this by cycling hot water through the brew basket, and around the portafilter, ensuring that it is always at the right temperature for extraction. This is important because just a few degrees could be the difference between a good and great espresso.

The Pump

Contrary to manual piston machines which rely on a lever to pressurize water, rotating espresso machines rely upon motorized pumps that provide the nine atmospheric bars of pressure needed to extract espresso. This pressure builds up by drawing tap water from a reservoir, and pumping it through a heat exchanger before being pushed through the ground coffee in the group head.

Pumps tend to be less expensive than piston-driven machines, and they tend to last longer, however both types of machine can degrade with overuse and insufficient cleaning. Pumps are also more complicated mechanically, which could increase the cost of even the most basic models.

Certain espresso machines utilize steam pressure instead of a pump to brew espresso. The drawback of this is that the same boiler that produces steam also increases the temperature of the water until it reaches boiling which can cause excessive extraction. In addition the machines often have to rebuild their pressure between cups, which requires time and energy.

A majority of espresso machines use the rotary or vibration pump, which has a vibration model that uses a vibrating disc that generates the pressure, and a rotary model pushing hot water through the grounds at high speed. Both types of machine can produce an excellent espresso, but the rotary pumps are quieter, and more durable than vibration pumps.

The Boiler

The boiler is the element that heats water to an optimal temperature for extraction. The resulting steam reaches the portafilter, which contains the ground espresso coffee, and gets funnelled down into the cup. During this process, steam creates pressure that pushes through the grounds of the coffee. This results in a whipped-up top espresso machines of the espresso. This is one of the main characteristics of a great espresso.

There are three distinct types of espresso machines, each having distinct pumps and the temperature of the brew. There are also different ways that the brew can be controlled, as well as the size of the cup that the maker can create.

The first espresso machines were steam-based. The earliest espresso machines were steam-type machines. The coffee tasted bitter and burnt. This is why Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most commonly used espresso machine is a semiautomatic with an electric pump. These are what people imagine when they think of an espresso machine. With a semi-automatic buy espresso machine machine, you have to grind the beans and then tamp them yourself but the pump regulates the flow of water and pressure. This is a great compromise between the human touch and the mechanised quality.

The Filter

Typically, espresso coffee maker machines use filters that separate the grounds of the coffee as they go through the hot water. The filter is also an important element of the temperature control system as it prevents the machine from overheating.

A filter also improves flavor as it allows for a longer flowering period. This allows the beans to release their flavor and gives an opportunity for better extraction.

It is important to keep in mind that even the best filter can produce a bad cup of coffee. The quality of the beans and the extraction, are still very important.

It's in this area that the magic happens. This is what makes espresso and filter coffee machine taste so good. The grouphead (also known as the brewhead) is where you put the portafilter, which is the thingy used to place the coffee grounds in, while making espresso.

In the steam-driven espresso machine hot water is heated in an airtight tank to create steam. Steam then pushes the hot water through the grounds with high pressure. These types of machines are generally less expensive and easier to maintain than pumps-driven models. They are however limited in their ability to create the perfect conditions for brewing as they only operate with 1-1.5 bar of pressure. The ideal shot requires 9-10 bars.

In recent years, compressed-air-pump-driven espresso machines have become more popular. They utilize an air compressor to push hot water into the grounds and are more portable than electric steam-driven machines.