It's The Ugly Truth About Machine Espresso
It's The Ugly Truth About Machine Espresso
Blog Article
How Does Machine Espresso Work?
Machine espresso uses precision pressure and incredible filter technology to produce the delicious coffee we enjoy. How exactly does it work?
In order to make espresso hot water is pushed under pressure through finely ground coffee. The process is similar to making drip coffee but the difference is in the pressure.
The Head of the Group
The name implies, the group head is the place you place your portafilter while brewing espresso. It is responsible for dispersing water into the portafilter and then controlling the pressure of the extraction. There are several different types of group head, each with their particular advantages and drawbacks. Some are focused on temperature stability, whereas others on pre-infusion features, and others are designed to control the lever. There are also some that come with a range of features, like the E61, which is the most popular choice among baristas due to its capacity to offer multiple benefits in a single package.
As you can see in the photo above the group head is made up of many notches in which you can place your portafilter and twist it with your hands to lock it in. A gasket of rubber is situated inside the notches to help create a seal while you insert your portafilter. The notches on the head allow for a precise placement of the portafilter, which is essential for an efficient extraction.
The group head not only allows the portafilter to be inserted easily however it also keeps the same temperature. It does this by cycling hot water through the brew basket, and around the portafilter, ensuring that it's always at the correct temperature for extraction. It is crucial to keep in mind that even a slight difference can make the difference between a good and great espresso.
The Pump
In contrast to manual piston machines which use a lever to pressurize water, rotating espresso machines rely upon motorized pumps to deliver the nine atmospheric bars of pressure necessary for espresso extraction. The pressure is created 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 less expensive than piston-driven machines, and tend to last longer, however both types of machines could degrade with overuse and insufficient cleaning. Pumps are also more complicated mechanically, and can add to the price of even the simple models.
Some espresso machines use steam pressure instead of a pump for brewing espresso. This can cause over-extraction because the boiler that makes steam also heats the water to boil. Additionally, these machines frequently have to restore their pressure between cups, which requires time and energy.
Many espresso machines utilize a vibration or rotary pump, with a vibrating model using a rotating disc that generates the pressure and rotating models that push hot water through the grounds under high speed. Both types of machine can make excellent espresso, but the rotary pumps are quieter, and more durable than vibration pumps.
The Boiler
The boiler is the element that heats the water to the optimal temperature for extraction. The steam that is created is then directed to the portafilter, which holds the espresso grounds. It is then funneled into the cup. During this process the steam is able to create enough pressure to push the grounds of the coffee through. This creates a crema on the top of the espresso. This is one of the main characteristics of a good espresso.
There are three types of espresso machines, each having a different type of pump and the temperature of the brew. There are many ways to control the brew as well as the size of the cup that can be produced by the machine.
The earliest espresso machines were steam types. The earliest espresso machines were steam types. The coffee tasted bitter and burned. This is why the Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.
The most commonly used espresso machine is a semiautomatic that has an electric pump. This is what people envision when they imagine an espresso machine. With a semi-automatic machine you need to grind the beans and then tamp them by hand. However, the pump provides regulated water flow and pressure. This is a great combination of human control and mechanized accuracy.
The Filter
Espresso machines usually have a filter that separates the grounds of the coffee from the hot water. The filter is also a vital element of the machine's temperature control, as it prevents overheating.
It also enhances flavor, as it can allow for a longer bloom phase. This helps the beans to release their flavor and gives an opportunity to improve extraction.
However it is crucial to remember that even a great filter could result in a bad cup of coffee, since the quality of the beans and extraction is crucial.
It's in this area that the magic takes place. This is the reason why espresso tastes so good. The grouphead (also known as the brewhead) is where you place the portafilter, the device which you put the grounds of coffee into when making espresso.
Steam-driven espresso machines use hot water that is heated in an airtight vessel to create steam. The steam then moves hot water through the grounds of coffee under high pressure. These machines are less expensive and easier for the user to maintain than pumps-driven models. They are click here however limited for creating the ideal conditions for brewing, as they operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.
In recent years, espresso machines driven by compressed air-pump have become increasingly popular. They make use of an air compressor to force hot water through the ground and are much more mobile than electric steam-driven espresso machines.