The 9 Things Your Parents Teach You About Machine Espresso

How Does machine espresso (Blogolenta post to a company blog) Work?

Machine espresso makes use of precise pressure and amazing filter technology to make the coffee we love. But how exactly does it work?

Espresso is created by forcing hot water at high pressure through finely ground coffee. The process is similar to making drip coffee for espresso machine. However, the pressure is the major difference.

The Group Head

As the name implies, the group head is the place you place your portafilter while making espresso. It is responsible for dispersing the water into the portafilter and controlling the pressure that results from the extraction. There are various kinds of group heads, each with their unique advantages and disadvantages. Some are designed for stability in temperature, while others are designed to handle pre-infusion. Others are built to control the lever. Some come with a combination of both, such as the E61. This is a favorite among baristas because it offers multiple advantages in a single package.

As you can see in the photo above the group head is made up of numerous notches that you can place your portafilter and then twist it by hand to secure it. A gasket made of rubber is placed in the notches to create a seal while you insert your portafilter. The notches permit precise placement of the portafilter. This is crucial to ensure an efficient extraction.

Apart from allowing you easily place your portafilter in, the group head is also responsible to ensure that the temperature remains even. This is achieved by cycling hot water around the portafilter and through the brew basin, ensuring that the temperature is always at the right level for extraction. This is important, as even a few degrees can mean the difference between excellent and great espresso.

The Pump

Contrary to manual piston machines which rely on a lever that pressurize water, rotating espresso machines rely upon motorized pumps that provide the nine atmospheric bars of pressure necessary for espresso extraction. This pressure is built up by pumping water through a heat-exchanger and then through the ground coffee.

Pumps tend to be cheaper than piston-driven machines, and they tend to last longer, although both types of machines could be damaged by excessive use and inadequate cleaning. Pumps are also more complicated mechanically, which can increase the cost of even the most basic models.

Certain espresso machines remove the pump entirely and use steam pressure to brew espresso. This can lead to over-extraction as the boiler that produces steam also causes the water to boil. The machines must also continually rebuild their pressure between cups. This requires energy and time.

Many espresso machines use the rotary or vibration pump. A vibration model employs a rotating disk to generate pressure, whereas a Rotary model pushes hot coffee through the ground at a fast speed. Both models are capable of producing excellent espresso, but the rotary models are quieter and more durable than vibration pumps.

The Boiler

The boiler is the part that heats water to an ideal temperature to extract. The resulting steam is then transferred to the portafilter which holds ground espresso maker beans and is then pumped into the cup. During this process, steam creates pressure and pushes through the grounds of the coffee. This results in a layer of crema on top. This is one of the hallmarks of a good best cheap espresso machine.

There are three types of espresso makers, and they differ in the type of pump they use and how hot the coffee is. There are a variety of ways that the brew may be controlled as well as the size of the cup that the machine can make.

The first espresso machines were steam type. They used only one boiler to make both steam and brew, but the pressure they could produce was not very high - two bars of atmospheric pressure maximum. The coffee tasted bitter and burnt. This is the reason why Milanese makers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

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

The Filter

Typically, espresso machines use filters to separate the grounds of coffee as they move through the hot water. The filter is also an essential component of the temperature control system, because it stops the machine from overheating.

A filter also improves flavor since it allows for a longer flowering phase. This lets the beans let their nuances out, and allows for better extraction.

However, it is important to remember that even a good filter could result in a bad cup of coffee, as the quality of the beans and extraction are essential.

This is where the magic happens, it's what makes an espresso really taste good. The grouphead (also known as the brewhead) is where you put the portafilter, the device that you put the coffee grounds in, when making espresso.

In a steam-driven espresso machine small machine hot water is heated in an airtight tank to produce steam, which is then pushed through the grounds at a high end espresso machine pressure. These machines are cheaper and easier for the owner to maintain than pumps-driven models. However, they are not as efficient in their capacity to create the perfect conditions for brewing, since they operate at 1-1.5 bars of pressure. The perfect shot requires 9-10 bars.

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