10 Quick Tips About Machine Espresso

How Does Machine Espresso Work?

The machine espresso makes use of precision pressure, and a filtering system that is awe-inspiring to create the coffee you enjoy. How does it work exactly?

To make espresso hot water is forced under high pressure through finely ground coffee. The process is similar to that of making drip coffee. However the pressure is the major difference.

The Group Head

As the name suggests the group head is where you place your portafilter when making espresso. It disperses the water into the portafilter and regulates the pressure of the extraction. There are several different types of group heads each with its particular advantages and drawbacks. Some are focused on temperature stability, whereas others on pre-infusion features, and others are designed to control the lever. Some come with a combination of both, like the E61. This is a preferred choice for baristas as it provides a variety of advantages in one package.

As you can see in the photo above the head of the group is fitted with several notches. You place your portafilter in these notches and then twist the head to lock it. A rubber gasket is located inside the notches, which helps make a seal when you insert your portafilter. The notches on the head allow for a precise positioning of the portafilter which is vital for a consistent extraction.

The group head not only allows you to put in your portafilter easily however, it also keeps the same temperature. This is done by cycling hot water around the portafilter, and through the brew basin, ensuring the temperature is always right to extract the coffee. This is important because even a few degrees can mean the difference between good and excellent espresso.

The Pump

The motorized pumps in rotary espresso machines supply the nine atmospheric bar pressure required to extract espresso. This is different from manual piston machines that use levers. The pressure is created by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are generally more affordable and last longer than piston-driven machines. However, both types of machines can degrade because of frequent use and poor cleaning. Pumps are also more complex mechanically, which can raise the cost of even simplest models.

Some espresso machines employ steam pressure instead of a pump to brew espresso. The downside is that the boiler that produces steam also raises the temperature of water to boiling and can result in over-extraction. In addition the machines often have to restore their pressure between cups, which takes time and energy.

A large majority of espresso machines employ the rotary or vibration pump. A vibration model utilizes a vibrating disk to generate pressure, whereas the Rotary model pushes hot coffee through the ground at high speed. Both machines can make excellent espresso however rotary machines tend to be more stable, quieter and less likely to break down.

The Boiler

The boiler is used to heat the water to a temperature that is ideal for extraction. The steam that is produced reaches the portafilter containing the ground espresso and is then pumped into the cup. The steam generates enough pressure to push the grounds of coffee through. This results in a layer of crema on top. This is the hallmark of a great espresso.

There are three kinds of espresso makers, which differ in the kind of pump they use and the degree of heat that the coffee is. There are a variety of ways in which the brew could be controlled, as well as the dimensions of the cup the machine can produce.

The first espresso machines were steam-type. They had a single boiler to make steam and brew, however the pressure they were able to produce was very low - just two bars of atmospheric pressure maximum. This resulted in the Coffee for Espresso machine tasting bitter and burnt. This is why the Milanese makers Luigi Bezzerra and Desiderio Pavoni developed the modern espresso machine.

The most popular espresso maker is a semi-automatic machine that has an electric pump. These are the images people have when they think of an uk espresso machine machine. Semi-automatic machines require you to grind and tamp your beans yourself The pump, however, regulates the flow of water and pressure. This is an excellent compromise between human control and mechanised reliability.

The Filter

Espresso machines usually have a filter that separates the grounds of coffee from hot water. The filter is also an essential component of the machine's temp control, as it prevents overheating.

It also helps with flavor, since a filter allows for a longer bloom phase. This allows beans to release their flavor and gives an opportunity for a better extraction.

However it is crucial to keep in mind that even a top filter could result in a bad cup of coffee as the quality of the beans and extraction are important.

This is where the magic happens. It's what makes an espresso really taste great. The grouphead (also known as the brewhead) is where you place the portafilter, the thingy that you use bean to cup espresso machines put the coffee grounds in, when making espresso.

In an espresso machine that is driven by steam, hot water is heated in an airtight tank to create steam. Steam then pushes the hot water through the grounds with high end espresso machine pressure. These kinds of machines espresso machines are generally less expensive and simpler to maintain than pump-driven models. They are however limited for creating the ideal 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-driven espresso machines have become more popular. They utilize an air compressor to force the hot water through the grounds, and are far more portable than steam-driven electric machines.