13 Things About Machine Espresso You May Never Have Known
How Does Machine Espresso Work?
The machine espresso utilizes precision pressure, and filtering system that is awe-inspiring to make the coffee you enjoy. What exactly does it work?
To make espresso, hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee. However, it is the pressure that makes the main difference.
The Head of the Group
As the name suggests the group head is the place you place your portafilter while brewing espresso. It is responsible for dispersing water into the portafilter, and controlling the pressure of the resulting extraction. There are various kinds of group heads, each with their distinct advantages and drawbacks. Some are focused on temperature stability, others on pre-infusion options, and others are designed to control the lever. Some are a combination, like the E61. This is a preferred choice for baristas as it provides a variety of benefits in one package.
As you can see from the image above the head of the group is equipped with several notches. The portafilter is placed in these notches and then turn the head around to secure it. A gasket made of rubber is placed inside the notches, which helps create a seal as you insert your portafilter. The notches on the head allow for a precise placement of the portafilter, which is vital for an even extraction.
The group head does not just allow the portafilter to be inserted 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 correct temperature to extract. It is important to realize that even a few degree variation can mean the difference between a good and excellent espresso.
The Pump
Unlike manual piston machines, which use a lever to pressurize water, Rotary espresso machines rely on motorized pumps that provide the nine atmospheric bars of pressure that are required to extract espresso. The pressure builds by drawing tap water from a reservoir, and pumping it through a heat exchanger prior being shot through the ground coffee inside the group head.
Pumps are generally less expensive than piston-driven machines, and tend to last longer. However, both types of machines may get damaged through overuse and lack of cleaning. Pumps are also more complicated mechanically, and can add to the cost of even the most basic models.
Some espresso machines use steam pressure instead of a pump in order to brew espresso. This can lead to over-extraction as the boiler that produces steam also causes the water to boil. The machines must also constantly rebuild their pressure in between cups. This takes energy and time.
Many espresso machines use an rotary or a vibration pump. A vibration model uses the vibrating disk to create pressure, while a circular model pushes hot liquid through the ground at high speed. Both machines can produce excellent espresso, however rotary machines are quieter, more durable and less likely to break.
The Boiler
The boiler is the one that is used to heat the water to the perfect temperature to extract. The resulting steam is then transferred to the portafilter containing the ground espresso and gets funnelled down into the cup. The steam generates enough pressure to push the grounds of coffee through. This results in a layer of crema that is then poured over. This is one of the hallmarks of a great espresso.
There are three types of espresso makers, and they differ in the type of pump they employ and how hot the espresso is. There are many ways to control the brew as well as the size of cup that can be made by the machine.
The first espresso machines were steam-type. The first espresso machines were steam-type machines. This led to the coffee tasting burnt and bitter. This is why the Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni developed the modern espresso machine.
The most commonly used espresso maker is a semi-automatic machine with an electric pump. These are what people imagine when they think of an espresso maker. With a semi-automatic espresso machine, you need to grind the beans and tamp them by hand. However, the pump regulates the flow of water and pressure. This is a great compromise between the human touch and the mechanised consistency.
The Filter
Espresso machines typically use filters that separate the grounds of coffee from hot water. The filter is also a vital element of the machine's temperature control, since it helps to prevent overheating.
A filter also helps with flavor, as it permits a longer flowering period. This allows beans to release their nuances and gives an opportunity to improve extraction.
It is important to keep in mind that even the best filter can make a bad cup of coffee. The quality of the beans, as well as the extraction, remain crucial.
It's here that the magic happens. commercial espresso machine is what makes espresso taste so delicious. The grouphead, also referred to as the brewhead, is where the portafilter (the thing you put the ground coffee in) is placed when making espresso.
Steam-driven espresso machines use hot water heated in an airtight container to create steam. The steam then moves hot water through the grounds of coffee under high pressure. They are less expensive and easier to maintain than pumps-driven models. However, they are limited in their ability to create the ideal brewing conditions, because they operate at 1-1.5 bars of pressure. However, the perfect shot requires 9-10 bars.
In recent years, compressed air-driven espresso machines have been gaining popularity. They use an air compressor to force hot water into the ground and are more mobile than steam-driven electric espresso machines.