13 Things You Should Know About Machine Espresso That You Might Not Know
How Does Machine Espresso Work?
The machine espresso is made using precise pressure, as well as a filtering technology that is amazing to create the coffee you enjoy. But how exactly does it work?
In order to make espresso hot water is pushed under pressure through finely ground coffee and espresso machine. The process is similar to making drip coffee, but the difference is in the pressure.
The Group Head
The group head is the portafilter that is inserted when you are making espresso Machine Black friday. It disperses water into the portafilter and regulates the pressure of extraction. There are various kinds of group heads each with its particular advantages and drawbacks. Some focus on temperature stability, some on pre-infusion capabilities, while others are designed to control the lever. There are even some that have a combination of features, such as the E61, which is considered the classic choice among many baristas due to its capacity to provide multiple benefits in a single package.
As you can see from the picture above, the group head has a number of notches. You place your portafilter in these notches, then twist the head to lock it. There is also a gasket of rubber that resides inside the notches, which helps create an airtight seal after inserting your portafilter into the machine. The notches allow for the precise placement of the portafilter. This is essential for an even extraction.
The group head is not just able to allow the portafilter to be inserted easily however it also keeps the same temperature. This is done by cycling hot water around the portafilter, and through the brew-basket, ensuring that the temperature is always at the right level to extract the coffee. This is vital, because even a small difference in temperature can make the difference between excellent and great espresso.
The Pump
The motorized pumps that are used in rotary espresso machines supply the nine atmospheric bar pressure required for espresso extraction. This differs from manually operated piston machines that employ levers. The pressure is built by pumping water through a heat exchanger and then through the ground coffee.
Pumps are generally less expensive than piston-driven machines and tend to last longer, but both types of machines may be damaged by excessive use and inadequate cleaning. They also add mechanical complexity and can lead to the cost of even the simplest models.
Some espresso machines use steam pressure instead of a pump for brewing espresso. The drawback of this is that the same boiler that produces steam also increases the temperature of the water until it reaches boiling and can result in excessive extraction. They also have to constantly rebuild their pressure in between cups. This requires energy and time.
Many mini espresso maker machines utilize either a rotary or vibration pump, which has a vibration model using a rotating disc to create pressure, and the rotary model pushing hot water through the grounds under high speed. Both models are capable of producing excellent espresso coffee machine, however Rotary machines are quieter and more durable than vibration pumps.
The Boiler
The boiler is the element which heats the water to the optimal temperature to extract. The steam that is produced reaches the portafilter which holds ground espresso beans and is then pumped down into the cup. During this process the steam creates enough pressure to push the grounds of the coffee through. This results in a crema on top of the espresso. This is one of the main characteristics of a good espresso.
There are three different types of espresso machines, each with distinct pumps and the temperature of the brew. There are a variety of ways to control the amount of brew, as well as the size of cup that can be made by the machine.
The first espresso machines were steam-types. They utilized a single boiler to make both brew and steam, however, the pressure they could produce was not very high - two bars of atmospheric pressure, at most. The coffee tasted bitter and burnt. This is why the Milanese makers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.
The most common espresso machine is a semiautomatic one with an electric pump. These are what people imagine when they think of an espresso machine. Semi-automatic machines require you to grind and tamp your beans yourself however the pump controls the flow of water and pressure. This is a great compromise between the human touch and the mechanized quality.
The Filter
Typically, espresso machines utilize filters to separate the coffee grounds as they pass through the hot water. The filter is also an important part of the temperature control system, as it keeps the machine from overheating.
A filter can also help with flavor as it allows for the beans to flower for a longer period of time. This allows the beans to release their flavors, and also allows for better extraction.
It is important to keep in mind that even the best filter can result in a bad cup of coffee. The quality of the beans, as well as the extraction, remain vital.
This is where the magic happens, it's the thing that makes espresso taste great. The grouphead (also called the brewhead) is where you put the portafilter - the thingy used to place the coffee grounds into, while making espresso capsule machine.
In an espresso machine that is driven by steam, hot water is heated in an airtight container to create steam. Steam then pushes the hot water through the grounds under high end espresso machine pressure. These machines are less expensive and easier for the user to maintain than pumps-driven models. They are however limited in their ability 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 the ground. They are also more mobile than electric steam-driven espresso machines.