10 Things That Your Family Taught You About Machine Espresso
How Does Machine Espresso Work?
Machine espresso makes use of precise pressure and mind-blowing filter technology to create the perfect cup of coffee. What exactly does it work?
To make espresso, hot water is pushed under pressure through finely ground coffee espresso machine. The process is similar to making drip coffee however the main difference lies in the pressure.
The Head of the Group
The group head is the portafilter that you put in when making espresso. It is responsible for dispersing the water into the portafilter and then controlling the pressure that results from the extraction. There are a variety of types of group head each with its unique advantages and disadvantages. Some are specifically designed for stability of temperature while others are specifically designed to handle pre-infusion. Some are designed to control the lever. There are even some that have a combination of features, like the E61, which is to be the most popular among baristas for its ability to offer multiple benefits in a single package.
As you can see in the above photo, the group head has several notches where you place your portafilter and then twist it manually to secure it. A gasket made of rubber is positioned in the notches to create a seal when you insert your portafilter. The notches permit precise placement of the portafilter. This is crucial for an efficient extraction.
The group head not only lets the portafilter to be inserted easily but also maintains a constant temperature. This is achieved by cycling hot water around the portafilter and through the brew-basket to ensure the temperature is always right to extract the coffee. It is crucial to keep in mind that even a small difference can make the difference between a good and excellent espresso.
The Pump
In contrast to piston machines that are manually operated, that use a lever to pressurize water, rotating travel espresso maker machines rely upon motorized pumps to supply the nine atmospheric bars of pressure necessary to extract espresso. The pressure is created by pumping water through a heat exchanger and then through the ground coffee.
Pumps tend to be cheaper than piston-driven machines, and they tend to last longer, although both types of machine can become damaged due to excessive use and poor cleaning. They also make mechanically complex, which can result in a high price tag on even the most basic models.
Some barista espresso machine machines do away with the pump entirely and use steam pressure to brew espresso. The drawback is that the same dual boiler espresso machine that produces steam also raises the temperature of the water to the point of boiling, which can lead to over-extraction. Additionally the machines often have to rebuild their pressure between cups, which takes time and energy.
Many espresso machines use an rotary or a vibration pump. A vibration model uses an oscillating disk to create pressure, whereas the rotary model pushes hot water through the ground at a fast speed. Both types of machines are capable of producing excellent espresso, however the rotary pumps are quieter, and more durable than vibration pumps.
The Boiler
The boiler is used to heat the water to the ideal temperature for extraction. The steam produced will eventually reach the portafilter, which holds the espresso grounds. It is then pumped into the cup. The steam creates enough pressure to push the grounds of the coffee through. This results in a whipped-up the top of the espresso. This is a hallmark of a good espresso.
There are three kinds of espresso makers. They differ in the type of pump they employ and how hot the brew is. There are a variety of ways to control the strength of the brew and the size of the cup that can be produced by the machine.
The first espresso machines were steam-type. The earliest travel espresso maker machines were steam types. This resulted in the coffee tasting bitter and burnt. The modern espresso machine was invented by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.
The most commonly used espresso maker is a semi-automatic one with an electric pump. When people think of espresso machines, they picture these machines. With a semi-automatic machine, you need to grind the beans and then tamp them yourself but the pump provides regulated water flow and pressure. This is an excellent compromise between human touch and the mechanized accuracy.
The Filter
Typically, espresso machines utilize filters that separate the grounds of coffee when they pass through the hot water. The filter is also a vital component of the machine's temperature control, as it prevents overheating.
Filters also aid in flavor, as it permits an extended flowering time. This allows the beans to release their flavor and allows for a better extraction.
However it is crucial to remember that even a good filter could result in a bad cup of coffee, since the quality of the beans and extraction is important.
It's in this area that the magic occurs. This is the reason why espresso tastes so good. The grouphead, also called the brew head, is where the portafilter (the thingy you put the coffee grounds into) is placed when making espresso.
In a steam-driven espresso machine, hot water is heated in an airtight tank to produce steam, which then pushes the hot water through the grounds with high pressure. These machines are cheaper and easier for the user to maintain than pumps-driven models. However, they are limited in their ability to produce the ideal brewing conditions, since they are only operating at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bar.
In recent years, compressed-air-pump-driven espresso machines have become more popular. They use an air compressor to push hot water through the grounds and are much more portable than steam-driven electric machines.