Nine Things That Your Parent Taught You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso makes use of precise pressure and mind-blowing filter technology to create the coffee we love. But how exactly does it work?

To make an espresso hot water is pushed under pressure through finely ground coffee. The process is similar to making drip coffee but the difference is in the pressure.

The Head of the Group

As the name implies, the group head is the place you place your portafilter while brewing espresso. It is responsible for dispersing the water into the portafilter before controlling the pressure of the extraction. There are a variety of group heads each with distinct advantages and disadvantages. Some focus on temperature stability, while others on pre-infusion capabilities, and still others are designed to control the lever. Some have a combination, such as the E61. This is a favorite among baristas as it provides a variety of advantages in a single package.

As you can see in the picture above, the group head is fitted with several notches. The portafilter is placed into these notches and twist the head to lock it. A gasket of rubber is situated inside the notches, which helps create a seal as you insert your portafilter. The notches on the head allow for an exact positioning of the portafilter which is crucial to ensure an even extraction.

In addition to allowing you easily insert 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, making sure that it is always at the correct temperature to extract. It is important to remember that even a tiny difference can make the difference between a great and a excellent espresso.

The Pump

The motorized pumps in espresso machines that rotate provide the nine atmospheric bar pressure needed for espresso extraction. This is different from manual piston machines that use levers. This pressure is built up by pumping water through a heat exchanger and then through the ground coffee.

Pumps tend to be less expensive and last for longer than piston-driven machines. However, both types of machines can degrade due to excessive use and poor cleaning. They also increase the complexity of mechanical systems that can lead to a high price tag on even the simplest models.

Certain espresso machines do away with the pump entirely and utilize steam pressure to make espresso. The drawback is that the same boiler that produces steam also raises the temperature of water to the point of boiling which can cause over-extraction. In addition these machines are often required to rebuild their pressure between cups, which takes time and energy.

Many espresso machines use an rotary or a vibration pump. A vibration model makes use of the vibrating disk to create pressure, while a Rotary model pushes hot coffee through the ground at a rapid speed. Both machines can produce excellent espresso, however rotary machines are more quiet, durable and less likely to break.

The Boiler

The boiler will heat the water to the perfect temperature to extract. The resultant steam then reaches the portafilter containing the ground espresso and is then pumped down into the cup. During this process, steam creates pressure to push through the grounds of the coffee. This creates a layer crema that is then poured over. This is the hallmark of a great espresso.

There are three distinct types of espresso machines, each with a different type of pump and brew temperature. There are many ways to control the amount of brew, as well as the size of the cup that can be produced by the machine.

The first espresso machines were steam-type. The earliest buy espresso machine machines were steam-type machines. This resulted in the coffee for espresso machine tasting burnt and bitter. This is why the Milanese producers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.

The most well-known espresso maker is a semi-automatic device that has an electric pump. These are what people imagine when they think of an espresso maker. With a semi-automatic machine you must grind the beans and then tamp them yourself but the pump controls the flow of water and pressure. This is an excellent compromise between human touch and mechanized accuracy.

The Filter

Espresso machines usually use a filter that separates the grounds of the coffee from the hot water. The filter is also a crucial component of the temperature control system, since it helps prevent the machine from overheating.

A filter also improves flavor, as it permits the beans to flower for a longer period of time. This helps the beans to release their nuances and gives an opportunity for better extraction.

However it is crucial to keep in mind that even a top filter can result in a poor cup of coffee as the quality of the beans and extraction is still crucial.

It's here that the magic takes place. This is what makes commercial espresso machine taste so good. The grouphead (also known as the brewhead) is where you place the portafilter, which is the thingy used to place the coffee grounds in, when making espresso.

Steam-driven espresso machines make use of hot water that is heated inside an airtight vessel to create steam. The steam then pushes hot water through grounds of coffee at 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, as they operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

In recent years, espresso machines driven by a compressed air pump have become increasingly popular. They make use of an air compressor to push hot water across the ground and are more mobile than steam-driven electric best budget espresso machine machines.