The Most Advanced Guide To Machine Espresso
The Most Advanced Guide To Machine Espresso
Blog Article
How Does Machine Espresso Work?
The machine espresso uses precise pressure and filtering system that is awe-inspiring to create the coffee you love. How does it work exactly?
Espresso is made by pushing hot water under pressure through finely ground coffee. The process is similar to making drip coffee. However, the pressure is the main difference.
The Group Head
The group head is the portafilter is inserted when you are making espresso. It disperses water in the portafilter and controls the pressure of the extraction. There are many different types of group heads each with their own advantages and disadvantages. Some are specifically designed for temperature stability while others are built to handle pre-infusion. Some are designed to control the lever. Some have a combination of features, like the E61 one, which is the classic choice among many baristas because of its ability to provide multiple benefits in a single package.
As you can see from the photo above the group head is fitted with a variety of notches. You place your portafilter in these notches and then turn the head around to secure it. A rubber gasket is located inside the notches to help create a seal while you insert your portafilter. The notches on the head permit an exact positioning of the portafilter which is vital for an efficient extraction.
The group head not only allows the portafilter to be inserted easily but also maintains the temperature at a constant level. This is done by cycling hot water around the portafilter and through the brew-basket, ensuring that the temperature is always at the right level for extraction. It is crucial to keep in mind that even a slight difference can make the difference between a good and a excellent espresso.
The Pump
The motorized pumps that are used in rotary espresso machines supply the nine atmospheric bars of pressure required for espresso extraction. This is different from manual piston machines that use levers. The pressure builds up by drawing tap water from a reservoir and pumping it through a heat exchanger before it is shot through the ground coffee inside the group head.
Pumps are typically more affordable and last longer than piston-driven machines. However, both kinds of machines can deteriorate due to excessive use and insufficient cleaning. They also increase the complexity of mechanical systems and can lead to the cost of even the most basic models.
Some espresso machines remove the pump entirely and make use of steam pressure to make espresso. The downside is that the boiler that produces steam also increases the temperature of water until it reaches boiling, which can lead to over-extraction. The machines also need 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 vibrating model that uses a vibrating disc to generate the pressure, and the rotary model pushing hot water through the grounds under high speed. Both machines can produce excellent espresso however rotary machines tend to be more quiet, durable and less likely to fail.
The Boiler
The boiler heats the water to a temperature that is ideal for extraction. The steam that is created gets to the portafilter which holds the espresso grounds. The steam is then channeled into the cup. During this process, steam creates pressure and pushes through the grounds of the coffee. This results in a crema on the top of the espresso. This is a hallmark of a good espresso.
There are three kinds of espresso makers, which differ in the type of pump they use and how hot the coffee is. There are various ways to control the brew as well as the size of cup that can be made by the machine.
The first espresso machines were steam-based. They employed one boiler to make both brew and espresso machines steam, however the pressure they were able to produce was very low - just two bars of atmospheric pressure at the most. This resulted in the coffee tasting bitter and burnt. The modern espresso machine was created by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.
The most commonly used espresso maker is a semiautomatic machine with an electric pump. This is what people envision when they think of an espresso maker. Semi-automatic machines require you to grind and tamp the beans on your own, but the pump regulates the flow of water and pressure. This is a fantastic compromise between human control and mechanised accuracy.
The Filter
Espresso machines usually use filters that separate the coffee grounds from the hot water. The filter is also a vital element of the machine's temperature control, since it helps to prevent overheating.
It also enhances flavor, as a filter allows for a more prolonged bloom time. This allows the beans to release their flavor and allows for a better extraction.
However, it is important to keep in mind that even a great filter can result in a poor cup of coffee, because the quality of the beans and extraction are important.
It's in this area that the magic takes place. This is what makes espresso taste so delicious. The grouphead, sometimes referred to as the brew head, is where the portafilter (the thingy you put the ground coffee into) is placed when you're making espresso.
In the steam-driven espresso machine hot water is heated in an airtight container to create steam. Steam then pushes the hot water through the grounds under high pressure. These machines are cheaper and easier to maintain than pumps-driven models. They are however limited to create the perfect 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-driven espresso machines have been gaining popularity. They use an air-compressor to push hot water across the ground. They are also more mobile than electric steam-driven espresso machines.