How Does Machine Espresso Work?
The machine espresso utilizes precise pressure, as well as a filtering technology that is amazing to make the coffee you enjoy. How does it work exactly?
(Image: https://cdn.freshstore.cloud/offer/images/778/17243/sage-the-bambino-compact-coffee-machine-with-automatic-milk-frother-brushed-stainless-steel-17243.jpg)Espresso is produced by pushing hot water under high pressure through finely-ground coffee. The process is similar to that of making drip coffee. However it is the pressure that makes the main difference.
The Group Head
The group head is the portafilter that is inserted when you are making espresso. It is responsible for dispersing the water into the portafilter and then controlling the pressure of the resulting extraction. There are several different types of group head each with its unique advantages and disadvantages. Some focus on temperature stability, while others on pre-infusion features, and others are designed to control the lever. Some are a combination, such as the E61. This is a popular choice among baristas since it provides multiple advantages in one package.
As you can see in the above photo, the group head has several notches to place your portafilter and then twist it manually to lock it in. A gasket made of rubber is placed inside the notches, which helps create a seal when you insert your portafilter. The notches permit precise placement of the portafilter. This is essential for an accurate extraction.
Apart from allowing you effortlessly insert your portafilter the group head is also responsible to ensure that the temperature remains even. It does this by circulating hot water through the brew basket and around the portafilter, ensuring that it's always at the correct temperature for extraction. This is important because just a few degrees could make the difference between good and excellent espresso.
The Pump
The motorized pumps that are used in rotary espresso machines provide the nine atmospheric bar pressure needed for mini espresso machine extraction. This is different from manually operated piston machines that employ levers. This pressure is built up by pumping water through a heat-exchanger and then through the ground coffee.
Pumps tend to be cheaper and last longer than piston-driven machines. However, both types of machines can deteriorate because of excessive use and poor cleaning. Pumps are also more complex mechanically, which can raise the price of even the simple models.
Some espresso machines can eliminate the pump entirely and employ steam pressure to create espresso. This can cause over-extraction because the boiler that produces steam also heats the water until it comes to a boil. In addition these machines typically have to restore their pressure between cups, which takes time and energy.
Many espresso machines make use of an rotary or a vibration pump. A vibration model uses a vibrating disk to generate pressure, whereas a Rotary model pushes hot coffee through the ground at a fast speed. Both types of machines can produce an excellent espresso, however the rotary pumps are quieter, and more durable than vibration pumps.
The Boiler
The boiler is the one that will heat the water to the perfect temperature to extract. The resultant steam then reaches the portafilter, which contains ground travel espresso maker (click here now) beans and is then pumped into the cup. During this process the steam causes enough pressure to push the grounds of the coffee through. This creates a foam on the top of the espresso. This is one of the hallmarks of a great espresso.
There are three distinct types of espresso machines, each with different pumps and the temperature of the brew. There are various ways in which the brew can be controlled as well as the dimensions of the cup the machine is capable of making.
The earliest espresso machines were steam type. The earliest espresso machines were steam-type machines. This resulted in the coffee espresso machines tasting bitter and burnt. The modern espresso machine was developed by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.
The most commonly used espresso machine is a semiautomatic model with an electric pump. These are the images people have when they think of an espresso machine. Semi-automatic machines require you to grind and tamp the beans on your own The pump, however, regulates the flow of water and pressure. This is a great compromise between the human touch and the mechanised accuracy.
The Filter
Typically, espresso machines employ filters that separate the grounds of the coffee as they go through the hot water. The filter is also a vital component of the machine's temp control, as it prevents 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 vital.
This is where the magic happens, and it's what makes espresso taste good. The grouphead, sometimes referred to as the brewhead, is where the portafilter (the container you place the ground coffee in) is located when you're making espresso.
Steam-driven espresso machines make use of hot water that is heated inside an airtight container to make steam. The steam then pushes hot water through the grounds of coffee at high pressure. These types of machines tend to be less expensive and easier to maintain than pumps-driven models. They are however limited to create the ideal 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-pump-driven espresso machines have become more popular. They use an air compressor to force hot water through grounds and are much more portable than steam-driven electric machines.