9 Things Your Parents Teach You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso employs precise pressure and mind-blowing filter technology to make the coffee and espresso machine we love. What 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 Group Head

The group head is the portafilter that is inserted when you are making espresso. It is responsible for dispersing water into the portafilter, and controlling the pressure of the resulting extraction. There are many different kinds of group head, each with their particular advantages and drawbacks. Some are focused on temperature stability, whereas others on pre-infusion capabilities, and still others are designed to control the lever. There are also some that have a combination of features, like the E61, which is to be the most popular among baristas because of its ability to provide multiple benefits in one package.

As you can see from the picture above the group head is fitted with a variety of notches. You place your portafilter in these notches and then twist the head to secure it. There is also a rubber gasket that is a part of the notches to help create a seal when you insert your portafilter into the machine. The notches on the head permit an exact location of the portafilter which is necessary to ensure a consistent extraction.

The group head is not just able to allow the portafilter to be inserted easily however, it also keeps an even temperature. This is accomplished by cycling hot water around the portafilter, and through the brew-basket to ensure that the temperature is constant for extraction. It is important to realize that even a few degree deviation can make the difference between a decent and a excellent espresso.

The Pump

The motorized pumps used in espresso machines that rotate provide the nine atmospheric bars of pressure required for espresso extraction. This is different from manual piston machines that rely on a lever. This pressure is built up by pumping water through a heat exchanger and then through the ground coffee.

Pumps are generally less expensive and last for longer than piston-driven machines. However, both kinds of machines are susceptible to degrading because of excessive use and insufficient cleaning. Pumps are also more complicated mechanically, which could increase the cost of even most basic models.

Some espresso machines remove the pump completely and instead employ steam pressure to create espresso. The drawback is that the dual boiler espresso machine that produces steam also increases the temperature of the water to boiling, which can lead to excessive extraction. The machines must also constantly rebuild their pressure in between cups. This takes energy and time.

Many espresso machines utilize a vibration or rotary pump, with a vibration model that uses a vibrating disc that generates the pressure, and an rotary model that pushes hot water through the grounds at high speed. Both machines produce great espresso, however rotary machines are more quiet, durable and less likely to break.

The Boiler

The boiler is the component which heats the water to the ideal temperature for extraction. The steam that is produced reaches the portafilter, which contains the espresso coffee grounds. The steam is then channeled into the cup. During this process the steam causes enough pressure to push the grounds of coffee through. This results in a whipped-up top of the espresso. This is one of the hallmarks of a good espresso.

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

The first espresso machines were steam type. The first espresso machines were steam-type machines. The coffee tasted bitter and burnt. This is the reason Milanese makers Luigi Bezzerra and Desiderio Pavoni developed the modern espresso machine.

The most commonly used espresso maker is a semiautomatic machine with an electric pump. These are what people imagine when they think of an espresso machine. Semi-automatic machines require you to grind and tamp your beans yourself however the pump controls the water flow and pressure. This is an excellent solution that combines human control with mechanised reliability.

The Filter

Typically, espresso machine small machines employ filters to separate the grounds of the coffee as they go through the hot water. The filter is also a vital component of the temperature control system, as it prevents the machine from overheating.

It also improves flavor, as a filter can allow for a longer bloom phase. This allows the beans to release their nuances, and allows for better extraction.

However it is crucial to remember that even a great filter can make a terrible cup of coffee, because the quality of the beans and extraction is vital.

This is where the magic happens, it's the thing that makes an espresso really taste great. The grouphead, sometimes called the brew head, is the place where the portafilter (the thingy you put the ground coffee in) is placed when you're making espresso.

Steam-driven espresso machines make use of hot water heated in an airtight container to produce steam. The steam then pushes hot water into the grounds of best coffee espresso machine under high pressure. These machines are cheaper and are easier for the user to maintain than pumps-driven models. They are however limited to create the perfect brewing conditions as they only operate with 1-1.5 bar of pressure. The ideal shot requires 9-10 bars.

In recent years, compressed-air-pump-driven espresso machines have become more popular. They use an air compressor to force hot water into the ground and are more mobile than steam-driven electric espresso machines.