The 9 Things Your Parents Teach You About Machine Espresso
How Does Machine Espresso Work?
Machine espresso utilizes precise pressure and incredible filter technology to produce the delicious coffee we enjoy. How exactly does it work?
Espresso is made by pushing hot water at high pressure through finely ground coffee. The process is similar to making drip coffee, but the key difference is in the pressure.
The Group Head
The group head is the portafilter you insert when brewing espresso. It is responsible for dispersing the water into the portafilter and then controlling the pressure of the resulting extraction. There are numerous kinds of group heads each with their own advantages and drawbacks. Some are specifically designed for stability of temperature while others are specifically designed to handle pre-infusion. Others are built to control the lever. Some contain a variety of features, such as the E61, which is the standard choice for many baristas for its ability to provide multiple benefits in one package.
As you can see in the photo above, the group head has several notches to place your portafilter before twisting it with your hands to secure it. There is also a gasket made of rubber in the notches and helps to create an airtight seal when you insert your portafilter into the machine. The notches allow for precise placement of the portafilter. This is crucial for an accurate extraction.
The group head does not just allow you to place your portafilter easily but also maintains an even temperature. This is done by cycling hot water around the portafilter, and through the brew-basket to ensure that the temperature is constant for extraction. It is important to remember that even a small differences can make the distinction between a decent and a excellent espresso.
The Pump
The motorized pumps that are used in espresso machines rotary provide nine atmospheric bar pressure that is required to extract espresso. This differs from manual piston machines which use a lever. This pressure is built up by pumping water through a heat-exchanger and then through the ground coffee.
Pumps tend to be less expensive and last for longer than piston-driven machines. However, both kinds of machines are susceptible to degrading due to overuse and insufficient cleaning. They also make mechanically complex, which can result in an expensive price for even the most basic models.
Some espresso machines do away with the pump entirely and use steam pressure to brew espresso. The drawback is that the boiler that produces steam also increases the temperature of the water until it reaches boiling and can result in over-extraction. In addition these machines are often required to rebuild their pressure between cups, which requires time and energy.
A large majority of espresso machines employ either a vibration or rotary pump. A vibration model uses the vibrating disk to create pressure, while the Rotary model pushes hot coffee through the ground at a fast speed. Both machines produce great espresso however rotary machines tend to be more stable, quieter and less likely to fail.
The Boiler
The boiler is the one that is used to heat the water to the ideal temperature to extract. The steam that is created gets to the portafilter which holds the espresso grounds. It is then funneled into the cup. During this process, steam creates pressure and pushes through the grounds of the coffee. This results in a layer of crema on top. This is one of the hallmarks of a good espresso.
There are three kinds of espresso makers. They differ in the type of pump they use and the degree of heat that the brew is. There are many ways to control the brew as well as the size of cup that can be produced by the machine.
The first espresso machines were steam type. The first espresso machines were steam types. This led to the coffee tasting burnt and bitter. This is the reason Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.
The most well-known espresso maker is a semiautomatic machine with an electric pump. When people think of espresso machines, they envision these machines. Semi-automatic machines require you to grind and tamp the beans on your own, but the pump regulates the water flow and pressure. This is an excellent compromise between human touch and the mechanised consistency.
The Filter
Typically, espresso machines utilize filters that separate the coffee grounds as they pass through the hot water. The filter is also a vital component of the temperature control system as it prevents the machine from overheating.
It also aids in flavor as a filter can allow for a longer bloom phase. This allows beans to release their nuances and gives the chance for better extraction.
It is important to remember that even the finest filter could result in a poor cup of coffee. coffee machine espresso of the beans, as well as the extraction, are still crucial.
This is where the magic happens, it's the thing that makes espresso taste great. The grouphead, often referred to as the brew head, is where the portafilter (the thingy you put the coffee grounds into) is located when you're making espresso.
In a steam-driven espresso machine, hot water is heated in an airtight container to produce steam, which then pushes the hot water through the grounds under high pressure. These types of machines are generally less expensive and easier to maintain than pump-driven models. However, they are not as efficient in their capacity to create the ideal brewing conditions, since they are only operating at 1-1.5 bars of pressure. The perfect shot requires 9-10 bars.
In recent years, compressed air-driven espresso machines have been gaining popularity. They utilize an air compressor to push hot water through grounds and are much more portable than steam-driven electric machines.