The 10 Most Scariest Things About Machine Espresso
The 10 Most Scariest Things About Machine Espresso
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How Does Machine Espresso Work?
The machine espresso is made using precise pressure and filter technology that is awe-inspiring to make the coffee you love. How does it work exactly?
To make an espresso hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee, but the difference is in the pressure.
The Group Head
The name implies the group head is the place you place your portafilter while making espresso. It is responsible for dispersing the water into the portafilter and controlling the pressure that results from the extraction. There are a variety of types of group head each with its own advantages and disadvantages. Some are focused on temperature stability, others on pre-infusion features, and others are designed to control the lever. There are also some that contain a variety of features, like the E61 that is the standard choice for many baristas because of its ability to offer multiple perks in a single package.
As you can see in the image above, the group head is fitted with several notches. You can place your portafilter in these notches and then turn the head around to secure it. There is also a rubber gasket which is located inside the notches, which helps create the seal when you insert your portafilter into the machine. The notches allow for an exact placement of the portafilter. This is essential for an accurate extraction.
The group head not only allows you to put in your portafilter easily however it also keeps the temperature at a constant level. It does this by circulating hot water through the brew pan and around the portafilter, making sure that it is always at the correct temperature to extract. This is crucial, since just a few degrees could make the difference between a excellent and great espresso.
The Pump
In contrast to manual piston machines that use a lever to pressurize water, rotating espresso machines rely upon motorized pumps to provide the nine atmospheric bars of pressure needed to extract espresso. This pressure is built up by pumping water through a heat-exchanger and then through the ground coffee.
Pumps tend to be cheaper than piston-driven machines and tend to last longer, however both types of machines can degrade with overuse and insufficient cleaning. Pumps are also more complicated mechanically, which could increase prices of even simple models.
Some espresso machines do away with the pump completely and instead make use of steam pressure to make espresso. This can cause over-extraction because the boiler that makes steam also heats the water until it comes to a boil. In addition these machines typically have to restore their pressure between cups, which requires time and energy.
A large majority of espresso machines employ an rotary or a vibration pump. A vibration model uses the vibrating disk to create pressure, while the circular model pushes hot liquid through the ground at a fast speed. Both machines produce great espresso, however rotary machines are more quiet, durable and less likely to break down.
The Boiler
The boiler is the element that heats water to an ideal temperature to extract. The steam that is produced will eventually reach the portafilter, which holds the espresso grounds. It is then poured into the cup. The steam causes pressure to push through the grounds of the coffee. This creates a layer crema on top. This is a sign of a good espresso.
There are three kinds of espresso makers, which differ in the type of pump they employ and how hot the coffee is. There are various 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 employed only one boiler to make both steam and brew, however, the pressure they could produce was not very high - two bars of atmospheric pressure, at most. This led to the coffee tasting burnt espresso coffee machines uk and bitter. This is the reason why Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni developed the modern espresso machine.
The most popular espresso maker is a semi-automatic device that has 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 however the pump controls the water flow and pressure. This is an excellent compromise between human touch and mechanized accuracy.
The Filter
Espresso machines typically use filters that separate the grounds of coffee from hot water. The filter is also a vital component of the machine's temp control, as it prevents overheating.
It also helps with flavor, as a filter allows for a longer bloom phase. This allows the beans to let their nuances out and provides an opportunity for a better extraction.
However, it is important to remember that even a great filter can make a terrible cup of coffee, as the quality of the beans and extraction is still essential.
It's here that the magic happens. This is what makes espresso taste so delicious. The grouphead (also known as the brewhead) is where you put the portafilter, which is the thingy which you put the grounds of your coffee into when making espresso.
In an espresso machine that is driven by steam, hot water is heated in an airtight tank to create steam, which then pushes the hot water through the grounds under high pressure. These kinds of machines tend to be less expensive and easier to maintain than pumps-driven models. However, they are not as efficient in their ability to provide the ideal brewing conditions, since they operate at 1-1.5 bars of pressure. However, the perfect shot requires 9-10 bars.
In recent years, espresso machines driven by compressed air-pump have become increasingly popular. They use an air compressor to push hot water into the grounds and are more portable than electric steam-driven machines.