Nine Things That Your Parent Teach You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso employs precise pressure and mind-blowing filter technology to make the perfect cup of coffee. But how exactly does it work?

Espresso is made by forcing hot water at high pressure through finely ground coffee. The process is similar to making drip coffee, but the key difference is in the pressure.

The Group Head

As the name implies, the group head is where you insert your portafilter when brewing espresso. It disperses water into the portafilter and regulates the pressure of extraction. There are numerous kinds of group heads each with distinct advantages and drawbacks. Some are focused on temperature stability, whereas others on pre-infusion capabilities, while others are designed to control the lever. Some come with a combination of both, such as the E61. This is a popular choice among baristas because it offers multiple benefits in a single package.

As you can see from the above photo, the group head has a number of notches. It is possible to place your portafilter in these notches, then twist the head to secure it. There is also a rubber gasket in the notches to help create a seal when you insert your portafilter into the machine. The notches permit the precise placement of the portafilter. This is vital for a consistent extraction.

In addition to allowing you easily insert your portafilter, the group head is responsible for maintaining an even temperature. This is accomplished by cycling hot water around the portafilter, and through the brew-basket, making sure that the temperature is at the right level to extract the coffee. This is important, as just a few degrees could mean the difference between excellent and great espresso.

The Pump

The motorized pumps used in rotary espresso machines supply the nine atmospheric bar pressure required for espresso extraction. This is different from manual piston machines that rely on a lever. The pressure is created by pumping water through a heat exchanger and then through the ground coffee.

Pumps tend to be less expensive and last longer than piston-driven machines. However, both types of machines may degrade due to overuse and insufficient cleaning. Pumps are also more complicated mechanically, which can raise the cost of even the most basic models.

Certain pro espresso machine machines do away with the pump completely and instead employ steam pressure to create espresso. The disadvantage of this is that the same boiler that produces steam also increases the temperature of the water to boiling which can cause over-extraction. They also have to constantly rebuild their pressure in between cups. This takes energy and time.

A majority of espresso machines use a vibration or rotary pump, with a vibration model using a rotating disc to create the pressure and an rotary model that pushes hot water through the grounds under high speed. Both models can produce an excellent espresso, however the rotary models are quieter and more durable than vibration pumps.

The Boiler

The boiler will heat the water to a temperature that is ideal for extraction. 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 results in a layer of crema that is then poured over. This is the hallmark of a great espresso.

There are three kinds of pro espresso machine makers, and they differ in the kind of pump they use and the degree of heat that the espresso is. There are a variety of ways to control the brew as well as the size of the cup that can be made by the machine.

The earliest espresso machines were steam-based. The first espresso machines were steam types. This led to the coffee tasting bitter and burnt. The modern espresso machine was created by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.

The most well-known espresso maker is a semiautomatic machine that has an electric pump. When people think of espresso machines, they think of these machines. Semi-automatic machines require you to grind and tamp your beans yourself, but the pump regulates the flow of water and pressure. This is a great compromise between the human touch and the mechanized accuracy.

The Filter

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

It also helps with flavor, since a filter allows for a more prolonged bloom time. This allows the beans to release their flavor and gives an opportunity to improve extraction.

It is important to keep in mind that even the most efficient filter could result in a poor cup of coffee. The quality of the beans, as well as the extraction, remain crucial.

This is where the magic happens, it's the thing that makes an espresso really taste great. The grouphead (also called the brewhead) is where you put the portafilter, the device which you put the coffee grounds in, while making espresso.

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

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