How Does Machine Espresso Work?

The machine espresso makes use of precision pressure, and filter technology that is awe-inspiring to make the coffee you enjoy. How exactly does it work?

decent Espresso Machine is made by pushing hot water under pressure through finely-ground coffee. The process is similar to making drip coffee however the main difference lies in the pressure.

The Group Head

The group head is the portafilter that you place in the espresso maker when making it. It disperses water in the portafilter, and then regulates the pressure during the extraction. There are various kinds of group head each with its distinct advantages and drawbacks. Some are specifically designed for the stability of temperature while some are designed to handle pre-infusion. Others are made to control the lever. Some include a combination such as the E61. This is a preferred choice for baristas since it provides multiple benefits in one package.

As you can see from the picture above the group head is fitted with several notches. You can place your portafilter in these notches, then twist the head to secure it. A gasket of rubber is situated within the notches to create a seal when you insert your portafilter. The notches on the head permit an exact location of the portafilter which is essential to ensure a consistent extraction.

In addition to allowing you to easily connect your portafilter, the group head is also responsible to maintain an even temperature. This is done by cycling hot water around the portafilter, and through the brew-basket to ensure that the temperature is always at the right level for extraction. This is important because just a few degrees could mean the difference between good and excellent espresso.

The Pump

In contrast to manual piston machines that use a lever to pressurize water, Rotary italian espresso machine machines rely on motorized pumps that provide the nine atmospheric bars of pressure required to extract espresso. The pressure builds up by removing tap water from a reservoir, and pumping it through a heat exchanger prior to being pushed through the ground coffee inside the group head.

Pumps tend to be cheaper than piston-driven machines and tend to last longer, although both types of machines may be damaged by excessive use and inadequate cleaning. Pumps are also more complex mechanically, which can raise the price of even the simpler models.

Certain espresso machines do away with the pump completely and instead make use of steam pressure to make espresso. The drawback is that the boiler that produces steam also increases the temperature of water to the point of boiling which can cause excessive extraction. These machines also have to constantly rebuild their pressure in between cups. This takes energy and time.

A large majority of espresso machines employ the rotary or vibration pump. A vibration model makes use of a rotating disk to generate pressure, while a rotary model pushes hot water through the ground at a rapid speed. Both types of machines can make a great espresso, however the rotary pumps are quieter, and more durable than vibration pumps.

The Boiler

The boiler is the one that is used to heat the water to the perfect temperature for extraction. The steam that is produced reaches the portafilter that contains the ground espresso and is then pumped into the cup. During this process the steam creates enough pressure to push the grounds of the coffee through. This creates a foam on the top of the espresso. This is the hallmark of a good espresso.

There are three kinds of espresso makers, and they differ in the type of pump they employ and how hot the brew is. There are also different ways in which the brew can be controlled, as well as the size of the cup the maker can create.

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

The most common espresso maker is a semiautomatic machine that has an electric pump. This is what people envision when they imagine an espresso machine. Semi-automatic machines require you to grind and tamp the beans on your own The pump, however, regulates the flow of water and pressure. This is an excellent compromise between human touch and the mechanized consistency.

The Filter

Typically, espresso machines utilize filters to separate the grounds of coffee as they move through the hot water. The filter is also an important component of the temperature control system since it helps prevent the machine from overheating.

It also helps with flavor, as a filter allows for a more prolonged bloom time. This allows beans to release their flavor and gives an opportunity 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 crucial.

It's here that the magic occurs. This is what makes espresso maker for home taste so delicious. The grouphead (also called the brewhead) is where you place the portafilter, which is the thingy which you put the coffee grounds into, when making espresso.

Steam-driven espresso machines make use of hot water that is heated inside an airtight container to make steam. The steam then pushes hot water into 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 ideal brewing conditions as they only operate with 1-1.5 bar of pressure. The ideal shot requires 9-10 bars.

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