How To Explain Machine Espresso To Your Grandparents
How Does Machine Espresso Work?
The machine espresso is made using precision pressure, and filtering technology that is amazing to make the coffee you love. What exactly is it?
Espresso is created by forcing hot water under pressure through finely-ground coffee. The process is similar to making drip coffee but the difference is in the pressure.
The Head of the Group
The group head is the portafilter is inserted when you are making buy espresso machine. It is responsible for dispersing the water into the portafilter, and controlling the pressure of the extraction. There are various kinds of group heads, each with their own advantages and drawbacks. Some are focused on temperature stability, some on pre-infusion capabilities, while others are designed to control the lever. Some are a combination, like the E61. This is a very popular choice for baristas because it offers multiple advantages in one package.
As you can see from the picture above the head of the group is equipped with several notches. You place your portafilter in these notches and then turn the head around to secure it. There is also a gasket made of rubber that is a part of the notches, which helps create an airtight seal after inserting your portafilter into the machine. The notches on the head allow for a precise placement of the portafilter, which is essential to ensure an efficient extraction.
Aside from allowing you to easily place your portafilter in, the group head is also responsible for maintaining a consistent temperature. This is achieved by cycling hot water around the portafilter, and through the brew basin, ensuring the temperature is always right for extraction. This is important, as even a small espresso machine difference in temperature can make the difference between a good and excellent espresso.
The Pump
In contrast to piston machines that are manually operated, which rely on a lever that pressurize water, Rotary espresso machines rely on motorized pumps to deliver the nine atmospheric bars of pressure that are required to extract espresso. This pressure builds up by drawing tap water from a reservoir, and pumping it through a heat exchanger before it is shot through the ground coffee inside the group head.
Pumps tend to be less expensive than piston-driven machines and tend to last longer, but both types of machines could be damaged by excessive use and inadequate cleaning. Pumps are also more complex mechanically, and can add to the price of even the simplest models.
Some espresso machines employ steam pressure instead of a pump in order to brew espresso. This can cause over-extraction because the boiler that produces steam also heats the water to boil. Additionally these machines typically have to rebuild their pressure between cups, which takes time and energy.
A majority of espresso machines use the rotary or vibration pump, with a vibrating model using a rotating disc that generates the pressure, and a rotary model pushing hot water through the grounds at high speed. Both machines can produce excellent espresso however rotary machines tend to be quieter, more durable and less likely to fail.
The dual boiler espresso machine (click home page)
The boiler is used to heat the water to a temperature that is ideal to extract. The resulting steam reaches the portafilter containing ground espresso beans and is then pumped into the cup. During this process the steam creates enough pressure to push the grounds of the coffee through. This creates a crema on the top of the espresso. This is a hallmark of a good espresso.
There are three kinds of espresso makers, and they differ in the type of pump they employ and the degree of heat that the espresso is. There are different ways to control the brew as well as the size of the cup that can be produced by the machine.
The earliest professional espresso maker machines were steam type. The earliest espresso machines were steam types. The coffee tasted bitter and burned. The modern espresso machine was designed by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.
The most popular espresso machine is a semiautomatic model with an electric pump. These are the things people think of when they think of an retro espresso machine maker. Semi-automatic machines require you to grind and tamp the beans yourself however the pump controls the water flow and pressure. This is a fantastic compromise between human control and mechanised consistency.
The Filter
Espresso machines typically have a filter that separates the grounds of the coffee from the hot water. The filter is also a vital element of the machine's temperature control, as it prevents overheating.
A filter can also help with flavor, as it permits a longer flowering period. This lets the beans release their flavors, and also allows for better extraction.
However it is crucial to remember that even a good filter can result in a poor cup of coffee, since the quality of the beans and extraction are essential.
It's in this area that the magic takes place. This is the reason why espresso tastes so delicious. The grouphead, sometimes called the brew head, is where the portafilter (the device you put the ground coffee into) is placed when making espresso.
Steam-driven espresso machines make use of hot water that is heated in an airtight vessel to create steam. The steam then pushes hot water into the grounds of coffee at high pressure. These types of machines are typically less expensive and simpler to maintain than pumps-driven models. However, they are not as efficient in their capacity to create the ideal conditions for brewing since they operate at 1-1.5 bars of pressure, while 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 push hot water into the grounds, and are far more portable than steam-driven electric machines.