10 Tell-Tale Symptoms You Must Know To Find A New Machine Espresso
10 Tell-Tale Symptoms You Must Know To Find A New Machine Espresso
Blog Article
How Does Machine Espresso Work?
The machine espresso utilizes precision pressure, and filtering technology that is amazing to create the coffee you love. How exactly does it work?
Espresso is produced by pushing hot water under high pressure through finely ground coffee. The process is similar to making drip coffee but the major difference is in the pressure.
The Head of the Group
The group head is the portafilter you place in the espresso maker when making it. It is responsible for dispersing water into the portafilter and controlling the pressure that results from the extraction. There are a variety of group heads each with their own advantages and drawbacks. Some are designed for temperature stability while others are designed to handle pre-infusion. Others are built to control the lever. Some come with a combination of both, like the E61. This is a favorite among baristas since it provides multiple advantages in a single package.
As you can see in the photo above, the group head is fitted with several notches. You place your portafilter inside these notches, and then twist the head to secure it. A gasket made of rubber is placed inside the notches, which helps create a seal while you insert your portafilter. The notches on the head allow for a precise placement of the portafilter, which is vital for an efficient extraction.
The group head does not just allow you to insert your portafilter easily however, it also keeps a constant temperature. This is achieved by cycling hot water around the portafilter, and through the brew-basket, making sure that the temperature is constant for extraction. It is important to remember that even a slight differences can make the distinction between a good and excellent espresso.
The Pump
The motorized pumps that are used in espresso machines that rotate provide the nine atmospheric bar pressure required for espresso extraction. This differs from manual piston machines that rely on a lever. The pressure builds by drawing tap water from a reservoir, and pumping it through a heat exchanger before being pumped through the ground coffee in the group head.
Pumps tend to be less expensive and last for longer than piston-driven machines. However, both types of machines can degrade because of frequent use and inadequate cleaning. Pumps are also more complex mechanically, and can add to prices of even simple models.
Certain espresso machines do away with the pump completely and use steam pressure to brew espresso. This can cause over-extraction because the boiler that produces steam also heats the water until it comes to a boil. The machines must also constantly rebuild their pressure in between cups. This takes energy and time.
Many espresso machines make use of either a rotary or vibration pump, which has a vibration model that uses a vibrating disc that generates the pressure and the rotary model pushing hot water through the grounds under high speed. Both types of machine can make a great espresso, but rotary machines are quieter and more durable than vibration pumps.
The Boiler
The boiler is the component which heats the water to the ideal temperature to extract. The steam produced gets to the portafilter which contains the espresso coffee grounds. It is then funneled into the cup. In this process, the steam creates pressure to push through the grounds of the coffee. This produces a layer of crema that is then poured over. This is the hallmark of a good espresso.
There are three kinds of espresso machines, each having different types of pumps and brew temperature. There are many ways to control the brew as well as the size of cup that can be made by the machine.
The earliest espresso machines were steam-based. They utilized a single boiler to make both brew and steam, however the pressure they were able to create was minimal - two bars of atmospheric pressure maximum. This resulted in the coffee tasting burnt and bitter. This is the reason Milanese producers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.
The most popular espresso maker is a semi-automatic device that has an electric pump. When people think of espresso machines, they think of these machines. With a semi-automatic espresso machine, you need to grind the beans and tamp them yourself but the pump is able to regulate the flow of water and pressure. This is a great compromise between human control and mechanised consistency.
The Filter
Espresso machines typically have a filter that separates the coffee grounds from the hot water. The filter is also a vital element of the temperature control system, because it stops the machine from overheating.
Filters also aid in flavor, as it permits an extended flowering time. This lets the beans release their flavors, and improves 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, and the extraction process are still crucial.
It's in this area that the magic happens. This is what makes espresso taste so good. The grouphead, often referred to as the brewhead, is where the portafilter (the thing you put the coffee ground into) is placed when you're making espresso.
Steam-driven espresso machines use hot water that is heated inside an airtight container to create steam. The more info steam then pushes hot water through grounds of coffee at high pressure. These kinds of machines are generally cheaper and easier to maintain than pumps-driven models. They are however limited in their ability for creating the ideal conditions for brewing since they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.
In recent years, compressed air pump-driven espresso machines have been gaining popularity. They utilize an air compressor to force the hot water through the grounds and are much more portable than electric steam-driven machines.