The 9 Things Your Parents Teach You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso utilizes precise pressure and incredible filter technology to produce the delicious coffee we enjoy. How exactly does it work?

In order to make espresso, hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee but the key difference is in the pressure.

The Head of the Group

The group head is the portafilter that you insert when brewing espresso. It disperses water in the portafilter and controls the pressure of the extraction. There are a variety of types of group heads each with its unique advantages and disadvantages. Some focus on temperature stability, whereas others on pre-infusion capabilities, while others are designed to control the lever. There are even some that have a combination of features, like the E61, which is considered to be the most popular among baristas due to its ability to offer multiple benefits in one package.

As you can see from the picture above the head of the group is fitted with several notches. You can place your portafilter into these notches and twist the head to secure it. A rubber gasket is located inside the notches to help create a seal while you insert your portafilter. The notches on the head allow for an exact position of the portafilter which is vital for an efficient extraction.

In addition to allowing you to easily place your portafilter in, the group head is also responsible to maintain an even temperature. This is achieved by cycling hot water around the portafilter and through the brew basin, ensuring that the temperature is constant for extraction. It is crucial to keep in mind that even a few degree deviation can make the difference between a good and a great espresso.

The Pump

Unlike manual piston machines, which rely on a lever that pressurize water, rotary espresso machines rely on motorized pumps to supply the nine atmospheric bars of pressure that are required to extract espresso. The pressure is created by drawing tap water from a reservoir and pumping it through a heat exchanger prior to it is shot through the ground coffee in the group head.

Pumps are generally less expensive and last for longer than piston-driven machines. However, both types of machines may degrade due to excessive use and inadequate cleaning. Pumps are also more complex mechanically, which can raise prices of even most basic models.

Some espresso machines use steam pressure instead of a pump in order to brew espresso. This can result in over-extraction because the boiler that produces steam also causes the water to boil. They also have to continually rebuild their pressure between cups. This takes energy and time.

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

The Boiler

The boiler is what heats the water to the perfect temperature for extraction. The resultant steam then reaches the portafilter containing the ground espresso coffee, and is then pumped into the cup. The steam generates enough pressure to push the coffee grounds through. This creates a layer crema that is then poured over. This is one of the hallmarks of a good espresso.

There are three different types of espresso machines, each with distinct pumps and brew temperature. There are a variety of ways to control the brew as well as the size of the cup that can be produced by the machine.

The first espresso machines were steam type. The earliest espresso machines were steam-type machines. This resulted in the coffee tasting bitter and burnt. This is the reason why Milanese makers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine with grinder machine.

The most commonly used espresso machine is a semiautomatic with an electric pump. When people think of espresso machines, they think of these machines. Semi-automatic espresso machine machines require you to grind and tamp the beans yourself, but the pump regulates the water flow and pressure. This is an excellent compromise between human touch and the mechanised accuracy.

The Filter

Typically, espresso machines utilize a filter to separate out the grounds of coffee when they pass 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 aids in flavor, as a filter allows for a longer bloom phase. This allows the beans to release their nuances and gives the chance for better extraction.

However, it is important to remember that even a good filter can produce a bad cup of coffee, since the quality of the beans and extraction are vital.

This is where the magic happens. It's what makes espresso maker for home taste great. The grouphead, also referred to as the brew head, is the place where the portafilter (the container you place the coffee ground into) is located when you're making espresso.

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

In recent years, compressed air-driven barista espresso machine 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 discount espresso machines machines.