Nine Things That Your Parent Teach You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso uses precision pressure and amazing filter technology to make the perfect cup of coffee. How exactly does it work?

To make espresso hot water is pushed under pressure through finely ground coffee. The process is similar to that of making drip coffee. However it is the pressure that makes the main difference.

The Head of the Group

The group head is the portafilter that you insert when brewing buy espresso makers. It disperses water in the portafilter, and controls the pressure of the extraction. There are many different types of group heads each with distinct advantages and disadvantages. Some are designed to provide temperature stability while others are designed to handle pre-infusion. Others are made to control the lever. Some have a combination, like the E61. This is a popular choice among baristas since it provides multiple benefits in a single package.

As you can see in the above photo the group head comes with many notches in which you can place your portafilter before twisting it by hand to lock it in. There is also a gasket of rubber which is located inside the notches, which helps create an airtight seal after inserting your portafilter into the machine. The notches on the head allow for an exact location of the portafilter which is necessary to ensure a consistent extraction.

The group head not only allows the portafilter to be inserted easily however it also keeps a constant temperature. It does this by circulating hot water through the brew basket and around the portafilter, making sure that it's always at the correct temperature for extraction. This is vital, because even a few degrees can make the difference between good and excellent espresso.

The Pump

The motorized pumps in rotary espresso machines provide the nine atmospheric bar pressure required for espresso extraction. This differs from manually operated piston machines that employ levers. The pressure builds up by drawing tap water from a reservoir and pumping it through a heat exchanger prior it is shot through the ground coffee in the group head.

Pumps are typically cheaper and last longer than piston-driven machines. However, both types of machines can degrade due to overuse and inadequate cleaning. Pumps are also more complex mechanically, and can add to prices of even most basic models.

Some espresso machines do away with the pump completely and use steam pressure to brew espresso. This can result in over-extraction because the boiler that produces steam also causes the water to boil. In addition, these machines frequently have to rebuild their pressure between cups, which requires time and energy.

A large majority of espresso machines employ the rotary or vibration pump. A vibration model uses a vibrating disk to generate pressure, whereas the Rotary model pushes hot coffee through the ground at high speed. Both models can make excellent espresso, however Rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the part that heats water to the optimal temperature for extraction. The steam created 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 layer crema on top. This is a sign of a great espresso.

There are three different types of espresso machines, each having different pumps and the temperature of the brew. There are also different ways that the brew may be controlled as well as the size of the cup that the machine can produce.

The earliest espresso machines were steam type. The earliest espresso machines were steam-type machines. The coffee tasted bitter and burned. This is the reason why Milanese makers Luigi Bezzerra and Desiderio Pavoni created the modern espresso coffee makers machine.

The most popular small espresso machine maker is a semiautomatic machine with an electric pump. When people think of espresso machines, they think of these machines. Semi-automatic machines require you to grind and tamp the beans yourself while the pump controls the water flow and pressure. This is an excellent compromise between human touch and mechanized quality.

The Filter

Typically, espresso machines have a filter to separate out the grounds of coffee when they pass through the hot water. The filter is also an essential component of the machine's temperature control, as it prevents overheating.

Filters also aid in flavor since it allows for the beans to flower for a longer period of time. This allows beans to release their flavor and gives the chance for better extraction.

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

It's in this area that the magic happens. This is the reason why cheap espresso machine tastes so good. The grouphead, sometimes called the brew head, is the place where the portafilter (the thing you put the ground coffee in) is located when you're making espresso.

Steam-driven espresso machines make use of hot water heated in an airtight container to make steam. The steam then pushes hot water through grounds of coffee at high pressure. These types of machines are usually less expensive and simpler to maintain than pumps-driven models. However, they are limited in their capacity to create the ideal brewing conditions, since they are only operating at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bars.

In recent times, espresso machines powered by compressed air-pump are becoming increasingly popular. They utilize an air compressor to force the hot water through the grounds and are significantly more portable than electric steam-driven machines.