How Does Machine Espresso Work?

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

Espresso is made by pushing hot water at high pressure through finely-ground coffee. The process is similar to making drip coffee. However the pressure is the major difference.

The Head of the Group

The group head is the portafilter you place in the espresso maker when making it. It is responsible for dispersing water into the portafilter, and controlling the pressure that results from the extraction. There are many different types of group heads each with distinct advantages and disadvantages. Some are designed to provide stability in temperature, while others are built to handle pre-infusion. Some are designed to control the lever. Some include a combination like the E61. This is a preferred choice for baristas due to the fact that it has multiple benefits in a single package.

As you can see in the photo above the group head is equipped with several notches. It is possible to place your portafilter into these notches and twist the head to lock it. There is also a gasket of rubber that resides inside the notches and helps to create an airtight seal after inserting your portafilter into the machine. The notches allow for an exact placement of the portafilter. This is essential for an even extraction.

In addition to allowing you to effortlessly insert your portafilter the group head is also responsible for maintaining a consistent temperature. It does this by cycling hot water through the brew basket and Coffeee around the portafilter, ensuring that it's always at the right temperature to extract. This is crucial, since even a few degrees can make the difference between excellent and great espresso.

The Pump

The motorized pumps that are used in rotary cafe espresso machine machines provide the nine atmospheric bars of pressure required to extract espresso. This differs from manual piston machines which use levers. The pressure is created by pumping water through a heat exchanger and then through the ground coffee.

Pumps are generally less expensive than piston-driven machines, and tend to last longer, but both types of machine can get damaged through overuse and lack of cleaning. Pumps are also more complex mechanically, which can increase prices of even most basic models.

Certain espresso machines can eliminate the pump completely and use steam pressure to brew espresso. This could lead to over-extraction since the boiler that produces steam also heats the water until it comes to a boil. In addition these machines typically have to rebuild their pressure between cups, which takes time and energy.

A majority of espresso machines utilize a rotary or vibration pump. A vibration model makes use of an oscillating disk to create pressure, while the rotating model pushes hot water through the ground at a high speed. Both machines can make great espresso but rotary machines are quieter, more durable and less likely to break down.

The Boiler

The boiler is what heats the water to the right temperature for extraction. The steam that is created will eventually reach the portafilter, which is a container for espresso grounds. It is then poured into the cup. In this process, the steam creates pressure to push through the grounds of the coffee. This creates a crema on top of the espresso. This is a hallmark of a good espresso.

There are three types of De'Longhi Stilosa EC260.BK Espresso Coffee Machine - Premium Quality machines, each with different types of pumps and brew temperature. There are various ways to control the amount of brew, as well as the size of the cup that can be made by the machine.

The first 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 created by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso machine is a semiautomatic that has an electric pump. When people think of espresso machines, they picture these machines. Semi-automatic machines require you to grind and tamp the beans by yourself however the pump controls the water flow and pressure. This is a great compromise between the human touch and the mechanized accuracy.

The Filter

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

It also enhances flavor as a filter allows for a longer bloom time. This lets the beans let their nuances out, and also allows for better extraction.

However it is crucial to keep in mind that even a good 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 occurs. This is what makes espresso taste so delicious. The grouphead (also known as the brewhead) is where you put the portafilter, the device used to place the coffee grounds in, when making espresso.

In a steam-driven espresso machine hot water is heated in an airtight container to create steam. This is then pushed through the grounds at high pressure. These kinds of machines are generally less expensive and simpler to maintain than pump-driven models. However, they are limited in their ability to produce the perfect brewing conditions since they operate at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bar.

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