20 Important Questions To To Ask About Machine Espresso Before You Dec…

How Does Machine Espresso Work?

Machine espresso uses precision pressure and mind-blowing filter technology to make the delicious coffee we enjoy. But how exactly does it work?

Espresso is made by forcing hot water at high pressure through finely-ground coffee. The process is similar to making drip coffee. However it is the pressure that makes the main difference.

The Head of the Group

As the name implies, the group head is the place you put your portafilter in when making espresso. It disperses the water into the portafilter, and then controls the pressure of the extraction. There are many different types of group heads each with their own advantages and drawbacks. Some are focused on temperature stability, some on pre-infusion capabilities, and still others are designed to control the lever. Some include a combination like the E61. This is a very popular choice for baristas since it provides multiple benefits in one package.

As you can see in the image above The group head features several notches where you put your portafilter, then twist it with your hands to lock it in. There is also a rubber gasket which is located inside the notches to help create an airtight seal when you insert your portafilter into the machine. The notches on the head allow for an exact location of the portafilter which is essential for a consistent extraction.

Apart from allowing you effortlessly insert your portafilter the group head is responsible to ensure that the temperature remains even. It does this by circulating hot water through the brew container and around the portafilter, making sure that it's always at the correct temperature for extraction. This is vital, because even a small difference in temperature can make the difference between excellent and great espresso.

The Pump

Contrary to manual piston machines that use a lever to pressurize water, rotary espresso machines rely on motorized pumps to provide the nine atmospheric bars of pressure necessary to extract espresso. This pressure is built up by pumping water through a heat exchanger and then through the ground coffee.

Pumps tend to be cheaper and last longer than piston-driven machines. However, both kinds of machines can deteriorate due to excessive use and poor cleaning. They also add mechanical complexity and can lead to a high price tag on even the most basic models.

Some Salter EK4369 Barista Pro Espresso Maker 15Bar machines eliminate the pump completely and utilize steam pressure to make espresso. This can cause over-extraction because the boiler that produces steam also heats the water until it comes to a boil. The machines also need to constantly rebuild their pressure between cups. This takes energy and time.

Many italian espresso machines machines utilize the rotary or Coffeee vibration pump, with a vibrating model that uses a vibrating disc that generates the pressure and an rotary model that pushes hot water through the grounds under high speed. Both machines can make great espresso but rotary machines are more stable, quieter and less likely to break.

The Boiler

The boiler is the element that heats water to the ideal temperature for extraction. The steam produced gets to the portafilter which is the container that holds the espresso coffee grounds. It is then funneled into the cup. During this process the steam is able to create enough pressure to push the coffee grounds through. This creates a foam on top of the espresso. This is one of the main characteristics of a great espresso.

There are three distinct types of espresso machines, each having different types of pumps and brew temperature. There are different ways that the brew can be controlled as well as the size of the cup that the machine is capable of making.

The first espresso machines were steam-types. They employed only one boiler to make steam and brew, but the pressure they could produce was very low - just two bars of atmospheric pressure, at most. The coffee tasted bitter and burned. The modern espresso machine was designed by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.

The most well-known espresso machine is a semiautomatic that has an electric pump. When people think of espresso machines, they imagine these machines. Semi-automatic machines require you to grind and tamp the beans by yourself however the pump controls the flow of water and pressure. This is a great compromise between the human touch and mechanized consistency.

The Filter

Typically, espresso machines utilize filters to separate the grounds of coffee when they pass through the hot water. The filter is also a vital component of the machine's temp control, as it prevents overheating.

It also enhances flavor, as it allows for a longer bloom time. This allows the beans to let their nuances out, and allows for a better extraction.

However it is crucial to remember that even a top filter can produce a bad cup of coffee, because the quality of the beans and extraction is still essential.

It's in this area that the magic occurs. This is what makes espresso taste so good. The grouphead (also known as the brewhead) is where you put the portafilter, which is the thingy that you put the grounds of coffee into while making espresso.

Steam-driven espresso machines use hot water that is heated inside an airtight container to make steam. The steam then moves hot water through the coffee grounds under high pressure. These kinds of machines are typically cheaper and easier to maintain than pump-driven models. They are however limited to create the perfect conditions for brewing as they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

In recent years, compressed air-driven espresso machines have become more popular. They use an air compressor to force hot water through grounds and are more portable than electric steam-driven machines.