Notes

The 10 Most Terrifying Things About Machine Espresso
How Does Machine Espresso Work?

The machine espresso utilizes precise pressure and filtering technology that is amazing to create the coffee you love. How exactly does it work?

Espresso is made by pushing hot water under pressure through finely ground coffee. The process is similar to making drip coffee. However the pressure is the primary difference.

The Head of the Group

The group head is the portafilter you place in the espresso maker when making it. It disperses water into the portafilter and controls the pressure of the extraction. There are many different kinds of group head, each with their own advantages and disadvantages. Some are focused on temperature stability, whereas others on pre-infusion options, and others are designed to control the lever. Some contain a variety of features, such as the E61, which is considered the most popular choice among baristas for its ability to offer multiple perks in one package.

As you can see in the above image the group head is made up of numerous notches that you can put your portafilter, then twist it manually to secure it. A gasket made of rubber is placed within the notches to make a seal when you insert your portafilter. The notches on the head permit a precise positioning of the portafilter which is vital for an efficient extraction.

In addition to allowing you to effortlessly insert your portafilter the group head is also responsible to maintain an even temperature. It does this by cycling hot water through the brew container and around the portafilter to ensure that it's always at the right temperature for extraction. It is important to remember that even a few degree differences can make the distinction between a good and a great espresso.

The Pump


In contrast to manual piston machines which rely on a lever that pressurize water, rotary espresso machines rely on motorized pumps to provide the nine atmospheric bars of pressure necessary to extract espresso. The pressure is created by drawing tap water from a reservoir and pumping it through a heat exchanger before being pushed through the ground coffee in the group head.

Pumps are generally less expensive than piston-driven machines and tend to last longer, although both types of machine can become damaged due to excessive use and poor cleaning. Pumps are also more complex mechanically, which can raise the price of even the simplest models.

Some espresso machines use steam pressure instead of a pump for brewing espresso. This can cause over-extraction because the boiler that makes steam also causes the water to boil. The machines must also constantly rebuild their pressure between cups. This takes energy and time.

A majority of espresso machines use an rotary or vibrating pump, with a vibrating model using a vibrating disc to create pressure and an rotary model that pushes hot water through the grounds at high speed. Both machines produce great espresso but rotary machines are more stable, quieter and less likely to break down.

The Boiler

The boiler is the part which heats the water to the optimal temperature for extraction. The resulting steam is then transferred to the portafilter containing the ground espresso coffee, and is then pumped down into the cup. During this process the steam causes enough pressure to push the grounds of coffee through. This creates a crema on the top of the espresso. This is a sign of a good espresso.

There are three distinct types of espresso machines, each with a different type of pump and brew temperature. There are a variety of ways in which the brew could be controlled as well as the size of the cup the machine can produce.

The first espresso machines were steam-types. The first espresso machines were steam types. The coffee tasted bitter and burned. The modern espresso machine was developed by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso maker is a semi-automatic machine that has an electric pump. When people think of espresso machines, they imagine these machines. Semi-automatic machines require you to grind and tamp your beans yourself however the pump controls the flow of water and pressure. This is a great combination of human control and mechanized consistency.

The Filter

Espresso machines typically have a filter that separates the coffee grounds from the hot water. The filter is also an important component of the temperature control system, as it keeps the machine from overheating.

It also enhances flavor, since a filter allows for a more prolonged bloom phase. This lets the beans let their nuances out, and improves extraction.

coffeee.uk is important to keep in mind that even the most efficient filter can make 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 the thing that makes espresso taste good. The grouphead (also called the brewhead) is where you put the portafilter, which is the thingy used to place the grounds of your coffee into while making espresso.

In the 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 less expensive and easier to maintain than pumps-driven models. However, they are limited in their ability to provide the perfect conditions for brewing, because they operate at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bars.

In recent years, espresso machines powered by compressed air-pump have become increasingly popular. They use an air-compressor to push hot water through the ground and are much more mobile than electric steam-driven espresso machines.

Homepage: https://www.coffeee.uk/categories/espresso-coffee-machines