14 Cartoons About Machine Espresso That Will Brighten Your Day
How Does Machine Espresso Work?
The machine espresso uses precision pressure, and filtering technology that is amazing to create the coffee you love. What exactly is it that makes it work?
To make an espresso hot water is pushed under pressure through finely ground coffee. The process is similar to making drip coffee. However, the pressure is the major difference.
The Head of the Group
As the name suggests, the group head is the place you put your portafilter in when making espresso. It is responsible for dispersing the water into the portafilter and then controlling the pressure of the resulting extraction. There are a variety of types of group heads, each with their particular advantages and disadvantages. Some are designed for stability of temperature while others are specifically designed to handle pre-infusion. Others are made to control the lever. There are some that contain a variety of features, such as the E61, which is the classic choice among many baristas due to its ability to offer multiple perks in a single package.
As you can see in the above image the group head comes with many notches in which you can place your portafilter before twisting it by hand to lock it in. A gasket of rubber is situated within the notches to make a seal when you insert your portafilter. The notches on the head allow for a precise placement of the portafilter, which is crucial for an efficient extraction.
The group head not only lets you to place your portafilter easily however it also keeps a constant temperature. This is accomplished by cycling hot water around the portafilter, and through the brew-basket, making sure that the temperature is constant for extraction. It is important to note that even a small differences can make the distinction between a decent and a excellent espresso.
The Pump
The motorized pumps in espresso machines rotary provide nine atmospheric bar pressure required for espresso maker for home extraction. This is different from manual piston machines that use levers. The pressure builds by drawing tap water from a reservoir and pumping it through a heat exchanger prior being pushed through the ground coffee in the group head.
Pumps are typically cheaper and last longer than piston-driven machines. However, both types of machines are susceptible to degrading because of frequent use and poor cleaning. They also increase the complexity of mechanical systems which can result in an expensive price for even the simplest models.
Certain discount espresso machines machines remove the pump completely and make use of steam pressure to make espresso. The drawback of this is that the boiler that produces steam also increases the temperature of water to boiling which could lead to over-extraction. Additionally the machines often have to rebuild their pressure between cups, which requires time and energy.
Many espresso machines make use of the rotary or vibration pump, with a vibrating model that uses a vibrating disc to create the pressure, and rotating models that push hot water through the grounds under high speed. Both machines can produce excellent espresso but rotary machines are more stable, quieter and less likely to fail.
The Boiler
The boiler heats the water to the perfect temperature to extract. The resulting steam is then transferred to the portafilter which holds ground espresso beans and is then pumped down into the cup. The steam creates pressure to push through the grounds of the coffee. This creates a crema on top of the espresso. This is one of the main characteristics of a good espresso.
There are three kinds of italian espresso machines makers, which differ in the kind of pump they use and the degree of heat that the espresso is. There are a variety of ways that the brew can be controlled and the dimensions of the cup the machine can make.
The earliest espresso machines were steam-based. They utilized a single 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 bitter and burnt. This is why Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni developed the modern espresso machine.
The most common espresso maker is a semi-automatic device with an electric pump. These are what people imagine when they think of an espresso maker. With a semi-automatic machine you grind the beans and then tamp them by hand, but the pump regulates the flow of water and pressure. This is a great compromise between the human touch and mechanized accuracy.
The Filter
pro espresso machine machines usually use a filter that separates the grounds of coffee from hot water. The filter is also an essential element of the machine's temperature control, as it prevents overheating.
Filters also aid in flavor, as it permits a longer flowering period. This helps the beans to release their nuances and gives an opportunity to improve extraction.
However it is crucial to remember that even a top filter can result in a poor cup of coffee, since the quality of the beans and extraction is important.
It's in this area that the magic takes place. This is the reason why espresso tastes so delicious. The grouphead, also called the brew head, is where the portafilter (the thingy you put the ground coffee in) is placed when making espresso.
In a steam-driven espresso machine hot water is heated in an airtight tank to produce steam, which then pushes the hot water through the grounds with high pressure. These machines are cheaper and easier to maintain than pumps-driven models. They are however limited in their ability to create the ideal conditions for brewing since they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.
In recent years, compressed-air-pump-driven espresso machines have become more popular. They use an air compressor to push hot water into the grounds and are much more portable than steam-driven electric machines.