9 . What Your Parents Taught You About Machine Espresso

How Does Machine Espresso Work?

The machine espresso makes use of precise pressure, as well as a filtering technology that is amazing to create the coffee you love. But how exactly does it work?

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

The Group Head

As the name suggests the group head is the place you place your portafilter when brewing espresso. It is responsible for dispersing water into the portafilter before controlling the pressure that results from the extraction. There are various kinds of group heads each with its distinct advantages and disadvantages. Some are focused on temperature stability, whereas others on pre-infusion features, and others are designed to control the lever. There are some that contain a variety of features, like the E61, which is the classic choice among many baristas because of its ability to offer multiple perks in a single package.

As you can see from the photo above, the group head has a number of notches. The portafilter is placed into these notches and twist the head to secure it. A rubber gasket is located within the notches to create a seal while you insert your portafilter. The notches on the head permit an exact location of the portafilter which is vital for a consistent extraction.

The group head does not just allow you to put in your portafilter easily, but it also maintains the same temperature. This is achieved by cycling hot water around the portafilter and through the brew-basket to ensure that the temperature is at the right level for extraction. This is important because even a few degrees can mean the difference between excellent and great espresso.

The Pump

In contrast to piston machines that are manually operated, that use a lever to pressurize water, the rotary espresso machines use motorized pumps to deliver the nine atmospheric bars of pressure needed for espresso extraction. The pressure is built by pumping water through a heat exchanger and then through the ground coffee.

Pumps are typically less expensive than piston-driven machines, and tend to last longer, but both types of machine can be damaged by excessive use and inadequate cleaning. They also increase the complexity of mechanical systems which can result in the cost of even the simplest models.

Some espresso machines employ steam pressure instead of a pump in order to brew espresso. This can result in over-extraction because the boiler that produces steam also heats the water until it comes to a boil. In addition, these machines frequently have to rebuild their pressure between cups, which requires time and energy.

Many espresso maker barista machines make use of either a vibration or rotary pump. A vibration model makes use of the vibrating disk to create pressure, whereas a circular model pushes hot liquid through the best ground coffee for espresso machine at a rapid speed. Both machines can make great espresso however rotary machines tend to be more quiet, durable and less likely to break down.

The Boiler

The boiler is the one that makes the water warm to a temperature that is ideal for extraction. The steam that is created is then directed to the portafilter, which holds the espresso grounds. It is then funneled into the cup. The steam generates 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 types of espresso machines, each having different pumps and the temperature of the brew. There are various ways in which the brew can be controlled and the size of the cup the machine can make.

The first espresso machines were steam-types. The earliest espresso machines were steam types. This led to the coffee tasting burnt and bitter. The modern espresso machine was invented by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso maker is a semi-automatic machine that has an electric pump. These are the images people have when they think of an espresso machine. With a semi-automatic machine you grind the beans and tamp them by hand. The pump is able to regulate the flow of water and pressure. This is an excellent compromise between human touch and the mechanised consistency.

The Filter

Espresso machines typically use filters that separate the grounds of the coffee from the hot water. The filter is also a crucial element of the temperature control system, because it stops the machine from overheating.

A filter can also help with flavor since it allows for an extended flowering time. This allows the beans to release their flavor and gives an opportunity to improve extraction.

However, it is important to keep in mind that even a great filter can result in a poor cup of coffee, since the quality of the beans and extraction is still crucial.

This is where the magic happens, it's what makes an professional espresso machine for home (click here) really taste great. The grouphead, often referred to as the brewhead, is 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 that is heated inside an airtight vessel to create steam. The steam then pushes hot water into the grounds of coffee under high pressure. These machines are less expensive and easier for the user to maintain than pumps-driven models. However, they are not as efficient in their capacity to create the perfect brewing conditions because they operate at 1-1.5 bars of pressure. However, the perfect shot requires 9-10 bars.

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