5 Laws That ll Help The Machine Espresso Industry
How Does Machine Espresso Work?
Machine espresso utilizes precise pressure and amazing filter technology to make the delicious coffee we enjoy. But how exactly does it work?
Espresso is made by forcing hot water under high pressure through finely-ground coffee. The process is similar to making drip coffee, but the key difference is in the pressure.
The Head of the Group
The group head is the portafilter that you insert when brewing espresso. It disperses water into the portafilter and controls the pressure of the extraction. There are numerous kinds of group heads each with its own advantages and disadvantages. Some are designed for the stability of temperature while some are built to handle pre-infusion. Others are built to control the lever. Some are a combination, like the E61. This is a very popular choice for baristas since it provides multiple benefits in a single package.
As you can see in the image above the head of the group is equipped with several notches. It is possible to place your portafilter inside these notches, and then twist the head to lock it. There is also a gasket of rubber which is located inside the notches and helps create an airtight seal when you insert your portafilter into the machine. The notches on the head allow for a precise position of the portafilter which is necessary for an even extraction.
The group head not only allows you to insert your portafilter easily but also maintains an even temperature. It does this by cycling hot water through the brew basket, and around the portafilter, ensuring that it's always at the right temperature to extract. It is important to realize that even a tiny deviation can make the difference between a great and a great espresso.
The Pump
Unlike manual piston machines, which rely on a lever that pressurize water, Rotary espresso machines rely on motorized pumps to provide the nine atmospheric bars of pressure needed for espresso extraction. The pressure builds up by removing tap water from a reservoir, and pumping it through a heat exchanger prior being shot through the ground coffee in the group head.
Pumps are typically more affordable and last longer than piston-driven machines. However, both types of machines can deteriorate because of excessive use and insufficient cleaning. Pumps are also more complex mechanically, and can add to the cost of even simplest models.
Certain buy espresso machine machines utilize steam pressure instead of a pump to make espresso. This can lead to over-extraction as the boiler that produces steam also warms the water to boil. Additionally these machines are often required to rebuild their pressure between cups, which takes time and energy.
A large majority of espresso machines employ an rotary or a vibration pump. A vibration model employs a vibrating disk to generate pressure, while the rotary model pushes hot water through the ground at a rapid speed. Both types of machine are capable of producing excellent espresso, however the rotary pumps are quieter, and more durable than vibration pumps.
The Boiler
The boiler is the element that heats water to an optimal temperature for extraction. The steam that is produced reaches the portafilter, which contains ground espresso beans and is then pumped into the cup. During this process the steam generates enough pressure to push the coffee grounds through. This creates a crema on the top of the espresso. This is a sign of a good espresso.
There are three types of espresso makers - click for info,, and they differ in the kind of pump they use and the degree of heat that the espresso is. There are also different ways that the brew can be controlled and the size of the cup that the machine is capable of making.
The first espresso machines were steam-type. They utilized one boiler to make both steam and brew, but the pressure they could generate was low - only two bars of atmospheric pressure at the most. The coffee tasted bitter and burned. The modern espresso machine was invented by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.
The most well-known espresso maker is a semi-automatic device with an electric pump. These are what people imagine when they imagine an espresso machine. Semi-automatic machines require you to grind and tamp your beans yourself The pump, however, regulates the water flow and pressure. This is a great combination of human control and mechanized accuracy.
The Filter
Espresso machines usually use filters that separate the grounds of the coffee from hot water. The filter is also a vital component of the temperature control system because it stops the machine from overheating.
A filter also helps with flavor, as it permits an extended flowering time. This allows beans to release their flavors and provides the chance for better extraction.
It is important to remember that even the best bean to cup espresso machine filter could result in a poor cup of coffee. The quality espresso machine of the beans, and the extraction, are still crucial.
This is where the magic happens, and it's what makes an espresso really taste good. The grouphead (also known as the brewhead) is where you put the portafilter, the thingy which you put the coffee grounds in, when making espresso.
In the steam-driven espresso machine hot water is heated in an airtight container to create steam. Steam then pushes the hot water through the grounds with high pressure. These kinds of machines are typically less expensive and easier to maintain than pumps-driven models. However, they are not as efficient in their ability to produce the ideal brewing conditions, since they are only operating at 1-1.5 bars of pressure. However, the perfect shot requires 9-10 bar.
In recent times, espresso machines powered by a compressed air compressor have become increasingly popular. They use an air-compressor to force hot water through the ground, and are more mobile than steam-driven electric espresso machines.