How Does Machine Retro Espresso Maker Work?

The machine espresso is made using precise pressure, as well as a filtering system that is awe-inspiring to create the coffee you love. But how exactly does it work?

Espresso is made by forcing hot water under high pressure through finely-ground coffee. The process is similar to making drip coffee. However, the pressure is the main difference.

The Head of the Group

The group head is the portafilter you insert when brewing espresso. It is responsible for dispersing water into the portafilter, and controlling the pressure of the resulting extraction. There are many different types of group heads, each with its own advantages and drawbacks. Some are designed for stability in temperature, while others are designed to handle pre-infusion. Others are made to control the lever. Some are a combination, such as the E61. This is a very popular choice for baristas due to the fact that it has multiple advantages in one package.

As you can see in the above photo the head of the group has a number of notches. You place your portafilter into these notches and twist the head to secure it. There is also a rubber gasket in the notches and helps create an airtight seal when you insert your portafilter into the machine. The notches allow for an exact placement of the portafilter. This is crucial for a consistent extraction.

In addition to allowing you to effortlessly insert your portafilter the group head is also responsible for maintaining a consistent temperature. This is achieved by cycling hot water around the portafilter, and through the brew-basket, making sure that the temperature is always at the right level for extraction. It is important to realize that even a small differences can make the distinction between a good and 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 for espresso extraction. This pressure is generated by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are typically less expensive and last for longer than piston-driven machines. However, both types of machines can degrade because of excessive use and inadequate cleaning. Pumps are also more complicated mechanically, which could increase the cost of even the simple models.

Certain espresso machines remove the pump completely and make use of steam pressure to make espresso. The drawback is that the boiler that produces steam also increases the temperature of water until it reaches boiling, which can lead to excessive extraction. These machines also have to constantly rebuild their pressure between cups. This requires energy and time.

Many espresso machines employ an rotary or vibrating pump, which has a vibration model using a rotating disc to create pressure, and rotating models that push hot water through the grounds at high speed. Both types of machines are capable of producing excellent espresso, but the rotary models are quieter and more durable than vibration pumps.

The Boiler

The dual boiler espresso machine will heat the water to the perfect temperature to extract. The resulting steam reaches the portafilter, which contains ground espresso beans and gets funnelled down into the cup. The steam creates pressure that pushes through the grounds of the coffee. This produces a layer of crema on top. This is one of the main characteristics of a great espresso.

There are three types of espresso makers, and they differ in the type of pump they use and the degree of heat that the espresso is. There are many ways to control the brew as well as the size of cup that can be produced by the machine.

The first espresso machines were steam type. The earliest espresso machines were steam-type machines. The best coffee espresso machine tasted bitter and burned. The modern espresso machine was invented by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most common espresso machine is a semiautomatic model with an electric pump. This is what people envision when they imagine an espresso machine. Semi-automatic machines require you to grind and tamp the beans on your own while the pump controls the water flow and pressure. This is an excellent combination of human control and mechanised accuracy.

The Filter

Typically, espresso coffee maker machines have filters that separate the coffee grounds as they pass through the hot water. The filter is also a vital element of the temperature control system, because it stops the machine from overheating.

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

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

This is where the magic happens, it's the thing that makes espresso taste good. The grouphead, also referred to as the brew head, is where the portafilter (the thingy you put the coffee grounds into) is located when you're making espresso.

Steam-driven espresso machines use hot water that is heated in an airtight container to create steam. The steam then pushes hot water through the grounds of coffee at high pressure. They are less expensive and easier for the owner to maintain than pumps-driven models. However, they are limited in their ability to produce the ideal conditions for brewing since they are only operating at 1-1.5 bars of pressure. The perfect shot requires 9-10 bars.

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