This Week's Top Stories About Machine Espresso
This Week's Top Stories About Machine Espresso
Blog Article
How Does Machine Espresso Work?
The machine espresso utilizes precision pressure, and filter technology that is mind-blowing to create the coffee you enjoy. How exactly does it work?
To make espresso hot water is pushed under pressure through finely ground coffee. The process is similar to that of making drip coffee. However, the pressure is the primary difference.
The Group Head
As the name suggests, the group head is where you insert your portafilter when brewing espresso. It is responsible for dispersing water into the portafilter and then controlling the pressure of the extraction. There are a variety of group heads each with its own advantages and drawbacks. Some are focused on temperature stability, whereas others on pre-infusion capabilities, and still others are designed to control the lever. There are some that come with a range of features, like the E61, which is the most popular choice among baristas for its ability to offer multiple perks in a single package.
As you can see from the photo above the head of the group is fitted with a variety of notches. The portafilter is placed into these notches and turn the head around to secure it. There is also a gasket made from rubber that resides inside the notches to help create a seal when you insert your portafilter into the machine. The notches on the head permit a precise placement of the portafilter, which is vital to ensure an efficient extraction.
In addition to allowing you to easily place your portafilter in, the group head is also responsible for maintaining an even temperature. This is done by cycling hot water around the portafilter and through the brew basin, ensuring that the temperature is always at the right level to extract the coffee. This is important, as just a few degrees could be the difference between a excellent and great espresso.
The Pump
Contrary to manual piston machines which rely on a lever to pressurize water, rotary espresso machines rely on motorized pumps to deliver the nine atmospheric bars of pressure needed for espresso extraction. The pressure is created by drawing tap water from a reservoir, and pumping it through a heat exchanger before being pumped through the ground coffee inside the group head.
Pumps tend to be less expensive and last for longer than piston-driven machines. However, both kinds of machines are susceptible to degrading because of excessive use and inadequate cleaning. They also make mechanically complex, which can result in costly prices for even the most basic models.
Certain espresso machines utilize steam pressure instead of a pump to make espresso. This could lead to over-extraction since the boiler that makes 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 make use of the rotary or vibration pump. A vibration model utilizes the vibrating disk to create pressure, while a circular model pushes hot liquid through the ground at a fast speed. Both types of machine can produce an excellent espresso, but the rotary models are quieter and more durable than vibration pumps.
The Boiler
The boiler is used to heat the water to the right temperature to extract. The resultant steam then reaches the portafilter that contains the ground espresso coffee, and is then funneled down into the cup. The steam creates enough pressure to push the grounds of the coffee through. This results in a layer of crema that is then poured over. This is one of the main characteristics of a great espresso.
There are three types of espresso makers, which differ in the type of pump they use and the degree of heat that the brew is. There are many ways to control the amount of brew, as well as the size of cup that can be produced by website the machine.
The earliest espresso machines were steam-based. They employed only one boiler to make both steam and brew but the pressure they could produce was not very high - two bars of atmospheric pressure at the most. The coffee tasted bitter and burned. The modern espresso machine was designed by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.
The most common espresso maker is a semiautomatic machine that has an electric pump. These are the images people have when they think of an espresso maker. If you have a semi-automatic machine you need to grind the beans and tamp them by hand. However, the pump controls the flow of water and pressure. This is an excellent compromise between human touch and the mechanized accuracy.
The Filter
Typically, espresso machines utilize a filter to separate out the grounds of coffee as they move through the hot water. The filter is also a vital element of the temperature control system, as it prevents the machine from overheating.
Filters also aid in flavor because it allows for an extended flowering time. This lets the beans release their flavors, and allows for better extraction.
It is important to keep in mind that even the most efficient filter can produce a bad cup of coffee. The quality of the beans and the extraction process, are still very important.
This is where the magic happens. It's what makes an espresso really taste great. The grouphead (also known as the brewhead) is where you place the portafilter - the thingy that you use to put the grounds of coffee into while making espresso.
Steam-driven espresso machines use hot water that is heated in an airtight container to create steam. The steam then pushes hot water into the grounds of coffee under high pressure. These machines are less expensive and easier for the user to maintain than pumps-driven models. However, they are not as efficient in their ability to produce the ideal brewing conditions, because they operate at 1-1.5 bars of pressure. The perfect shot requires 9-10 bars.
In recent times, espresso machines powered by a compressed air pump have become increasingly popular. They use an air compressor to push hot water across the ground and are much more mobile than electric steam-driven espresso machines.