11 Ways To Completely Revamp Your Machine Espresso
11 Ways To Completely Revamp Your Machine Espresso
Blog Article
How Does Machine Espresso Work?
Machine espresso employs precise pressure and amazing filter technology to make the delicious coffee we enjoy. What exactly does it work?
Espresso is created by forcing hot water under high pressure through finely-ground coffee. The process is similar to making drip coffee, but the key difference is in the pressure.
The Head of the Group
The name implies the group head is the place you place your portafilter while making espresso. 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 its own advantages and disadvantages. Some are focused on temperature stability, some on pre-infusion capabilities, while others are designed to control the lever. There are even some that include a mix of features, like the E61, which is considered the standard choice for many baristas due to its ability to offer multiple benefits in one package.
As you can see in the image above The group head features several notches to place your portafilter and then twist it by hand to secure it. There is also a gasket made from rubber which is located inside the notches, which helps create the seal when you insert your portafilter into the machine. The notches on the head permit an exact position of the portafilter which is necessary for an even extraction.
In addition to allowing you to easily connect your portafilter, the group head is also responsible for maintaining a consistent temperature. It does this by circulating hot water through the brew container and around the portafilter, ensuring that it's always at the correct temperature to extract. This is important, as even a few degrees can make the difference between a good and excellent espresso.
The Pump
The motorized pumps in espresso machines that rotate provide the nine atmospheric bar pressure needed to extract espresso. This is different from manual piston machines that rely on a lever. This pressure is generated by pumping water through a heat exchanger and then through the ground coffee.
Pumps are generally less expensive and last for longer than piston-driven machines. However, both types of machines are susceptible to degrading because of frequent use and poor cleaning. They also make mechanically complex that can lead to a high price tag on even the most basic models.
Certain espresso machines remove the pump completely and instead employ steam pressure to create espresso. This can lead to over-extraction as the boiler that makes steam also heats the water until it comes to a boil. Additionally these machines are often required to rebuild their pressure between cups, which requires time and energy.
A majority of espresso machines use either a rotary or vibration pump, which is a vibration model that uses a vibrating disc to create the pressure and rotating models that push 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 is the element that heats water to an ideal temperature to extract. The resulting steam is then transferred to the portafilter, which contains the ground espresso coffee, and gets funnelled down into the cup. During this process, steam causes pressure to push through the grounds of the coffee. This creates a crema on top of the espresso. This is the hallmark of a good espresso.
There are three kinds of espresso machines, each with a different type of pump and brew temperature. There are various ways in which the brew could be controlled and the size of the cup the machine can make.
The earliest espresso machines were steam type. They employed only one boiler to make both steam and brew however the pressure they were able to produce was very low - just two bars of atmospheric pressure, at most. The coffee tasted bitter and burned. The modern espresso machine was invented by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.
The most common espresso maker is a semi-automatic device with an electric pump. These are the images people have when they think of an espresso maker. With a semi-automatic machine you must grind the beans and tamp them by hand, but the pump controls the flow of water and pressure. This is an excellent solution that combines human control with mechanised accuracy.
The Filter
Espresso machines typically have a filter that separates the grounds of coffee from hot water. The filter is also a vital element of the machine's temperature control, since it stops overheating.
A filter also helps with flavor, as it permits a longer flowering phase. This allows the beans to release their flavor and allows for better extraction.
It is important to remember that even the best filter could result in a poor cup of coffee. The quality of the beans and the extraction process, remain vital.
It's here that the magic takes place. This is what makes espresso taste so good. The grouphead, sometimes referred to as the brew head, is where the portafilter (the thing you put the ground coffee in) sits when you're making espresso.
In a steam-driven espresso machine, hot water is heated in an airtight tank to create steam. Steam is then pushed through the grounds at a high pressure. These kinds of machines tend to be less expensive and easier to maintain than pump-driven models. They are however limited in their ability for creating the ideal conditions for brewing as they only operate with 1-1.5 professional espresso machine bar of pressure. The ideal shot requires 9-10 bars.
In recent years, compressed air-driven espresso machines have become more popular. They use an air compressor to push hot water through the ground. They are also more mobile than electric steam-driven espresso machines.