5 Killer Quora Questions On Machine Espresso
How Does Machine Espresso Work?
The machine espresso is made using precise pressure and filtering technology that is amazing to create the coffee you love. But how 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 but the major difference is in the pressure.
The Group Head
The group head is the portafilter that you place in the espresso maker when making it. It is responsible for dispersing the water into the portafilter and then controlling the pressure that results from the extraction. There are many different kinds of group head each with its particular advantages and drawbacks. Some are focused on temperature stability, whereas others on pre-infusion capabilities, while others are designed to control the lever. There are some that contain a variety of features, like the E61 one, which is the most popular choice among baristas due to its capacity to offer multiple perks in a single package.
As you can see in the image above, the group head is equipped with several notches. The portafilter is placed into these notches and twist the head to lock it. A rubber gasket is located inside the notches to help create a seal while you insert your portafilter. 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 lets you to place your portafilter easily, but it also maintains an even temperature. It does this by circulating hot water through the brew container and around the portafilter, making sure that it is always at the right temperature for extraction. This is crucial, since just a few degrees could mean the difference between good and excellent espresso.
The Pump
The motorized pumps in espresso machines rotary provide nine atmospheric bar pressure required for espresso extraction. This differs from manual piston machines that rely on a lever. The pressure builds up by removing tap water from a reservoir and pumping it through a heat exchanger prior to being shot through the ground coffee in the group head.
Pumps are typically less expensive than piston-driven machines and tend to last longer. However, both types of machine can become damaged due to excessive use and poor cleaning. Pumps are also more complicated mechanically, which could increase the price of even the simplest models.
Some espresso machines do away with the pump completely and use steam pressure to brew espresso. This can result in over-extraction because the boiler that produces steam also heats the water to boil. Additionally these machines are often required to rebuild their pressure between cups, which requires time and energy.
Many espresso machines employ a vibration or rotary pump, which is a vibration model that uses a vibrating disc that generates the pressure, and a rotary model pushing hot water through the grounds under high 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 makes the water warm to the right temperature for extraction. The resulting steam is then transferred to the portafilter containing the ground espresso coffee, and gets funnelled down into the cup. During this process the steam is able to create enough pressure to push the grounds of coffee through. This creates a layer crema that is then poured over. This is one of the main characteristics of a good 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 a variety of ways that the brew can be controlled and the dimensions of the cup the maker can create.
The first espresso machines were steam-based. They used a single boiler to make steam and brew, however the pressure they were able to produce was very low - just two bars of atmospheric pressure maximum. This resulted in the coffee tasting burnt and bitter. The modern espresso machine was developed by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.
The most well-known espresso machine is a semiautomatic with an electric pump. These are the things people think of when they think of an espresso machine. With a semi-automatic machine you need to grind the beans and tamp them by hand. The pump controls the flow of water and pressure. This is a fantastic solution that combines human control with mechanized accuracy.
The Filter
Espresso machines typically use filters that separate the grounds of the coffee from the hot water. The filter is also an essential component of the machine's temp control, since it helps to prevent overheating.
A filter can also help with flavor since it allows for a longer flowering phase. This allows the beans to release their nuances, and allows for better extraction.
It is important to remember that even the finest filter could result in a poor cup of coffee. The quality of the beans, and the extraction, are still crucial.
barista espresso coffee machine is where the magic happens. It's what makes an espresso really taste good. The grouphead, sometimes called the brewhead, is where the portafilter (the device you put the ground coffee into) is placed when you're 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 through the grounds of coffee under high pressure. These machines are cheaper and easier for the user to maintain than pumps-driven models. They are however limited to create the perfect conditions for brewing, as they operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.
In recent years, espresso machines powered by a compressed air pump have become increasingly popular. They use an air compressor to force hot water through the ground, and are more mobile than electric steam-driven espresso machines.