9 . What Your Parents Teach You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso employs precise pressure and mind-blowing filter technology to create the perfect cup of coffee. What exactly is it that makes it work?

Espresso is produced by pushing hot water under high pressure through finely-ground coffee. The process is similar to making drip coffee. However, the pressure is the major difference.

The Group Head

The group head is the portafilter you place in the espresso maker when making it. It distributes water into the portafilter, and then controls the pressure of the extraction. There are a variety of group heads, each with its own advantages and drawbacks. Some are designed for stability of temperature while others are specifically designed to handle pre-infusion. Others are built to control the lever. Some are a combination, such as the E61. This is a very popular choice for baristas because it offers multiple advantages in a single package.

As you can see in the above photo The group head features many notches in which you can place your portafilter before twisting it by hand to lock it in. A gasket made of rubber is placed inside the notches, which helps create a seal as you insert your portafilter. The notches allow for precise placement of your portafilter. This is crucial for an accurate extraction.

In addition to allowing you effortlessly insert your portafilter the group head is responsible for maintaining an even 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 to extract the coffee. This is important because even a small espresso machine difference in temperature can be the difference between a good and great espresso.

The Pump

In contrast to manual piston machines which rely on a lever to pressurize water, the rotary espresso machines use motorized pumps to supply the nine atmospheric bars of pressure needed for espresso extraction. The pressure builds up by removing tap water from a reservoir, and pumping it through a heat exchanger before being shot through the ground coffee in the group head.

Pumps are typically less expensive than piston-driven machines, and tend to last longer, but both types of machine can become damaged due to excessive use and poor cleaning. They also make mechanically complex, which can result in an expensive price for even the most basic models.

Certain espresso machines do away with the pump entirely and make use of steam pressure to make espresso. The downside is that the boiler that produces steam also raises the temperature of water until it reaches boiling which could lead to excessive extraction. These machines also have to constantly rebuild their pressure in between cups. This requires energy and time.

Many espresso machines make use of either a rotary or vibration pump, which is a vibration model using a vibrating disc that generates the pressure, and an rotary model that pushes hot water through the grounds under high speed. Both types of machine can make a great espresso, but Rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is used to heat the water to the right temperature to extract. The steam that is produced is then directed to the portafilter, which contains the espresso coffee grounds. It is then poured into the cup. During this process, the steam causes pressure to push through the grounds of the coffee. This creates a foam on the top of the espresso. This is one of the main characteristics of a great espresso.

There are three kinds of espresso makers, which differ in the type of pump they use and how hot the espresso is. There are many ways to control the brew and the size of the cup that can be made by the machine.

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

The most well-known espresso machine is a semiautomatic with an electric pump. When people think of espresso machines, they picture these machines. With a semi-automatic small espresso machine machine, you need to grind the beans and then tamp them yourself but the pump provides regulated water flow and pressure. This is an excellent compromise between human touch and the mechanized accuracy.

The Filter

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

It also enhances flavor, since a filter allows for a more prolonged bloom phase. This allows beans to let their nuances out and provides an opportunity to improve extraction.

However it is crucial bean to cup espresso machines remember that even a top filter could result in a bad cup of coffee, as the quality of the beans and extraction is still essential.

It's in this area that the magic occurs. This is the reason why espresso tastes so good. The grouphead, often referred to as the brewhead, is where the portafilter (the container you place the ground coffee in) is located when you're making espresso.

In an espresso machine that is driven by steam, hot water is heated in an airtight container to create steam. This then pushes the hot water through the grounds under high end espresso machine pressure. They are less expensive and are easier for the user to maintain than pumps-driven models. They are however limited to create the perfect conditions for brewing, as they operate with 1-1.5 bar of pressure. The ideal shot requires 9-10 bars.

In recent years, compressed air-driven espresso machines have been gaining popularity. They utilize an air compressor to push hot water through the grounds and are more portable than steam-driven electric machines.