The 10 Most Terrifying Things About Machine Espresso

How Does Machine Espresso Work?

Machine espresso utilizes precise pressure and incredible filter technology to produce the perfect cup of coffee. How does it work exactly?

Espresso is made by forcing hot water under pressure through finely-ground coffee. The process is similar to making drip coffee however the main difference lies in the pressure.

The Head of the Group

The name implies, the group head is the place you place your portafilter when brewing espresso. It disperses water into the portafilter, and then regulates the pressure during the extraction. There are a variety of group heads each with their own advantages and disadvantages. Some are designed to provide the stability of temperature while some are designed to handle pre-infusion. Others are built to control the lever. There are also some that come with a range of features, such as the E61, which is considered the most popular choice among baristas due to its ability to provide multiple benefits in a single package.

As you can see in the above image The group head features several notches to place your portafilter and then twist it by hand to secure it. A gasket of rubber is situated in the notches to create a seal while you insert your portafilter. The notches allow for the precise placement of the portafilter. This is crucial for an accurate extraction.

The group head not only allows you to put in your portafilter easily, but it also maintains the temperature at a constant level. This is done by cycling hot water around the portafilter and through the brew-basket to ensure that the temperature is at the right level for extraction. It is important to realize that even a slight difference can make the difference between a great and a great espresso.

The Pump

In contrast to manual piston machines that use a lever to pressurize water, the rotary espresso machines use motorized pumps to supply the nine atmospheric bars of pressure that are required for espresso extraction. This pressure builds up by removing tap water from a reservoir and pumping it through a heat exchanger prior to being pushed through the ground coffee in the group head.

Pumps tend to be less expensive than piston-driven machines and tend to last longer, however both types of machines may be damaged by excessive use and inadequate cleaning. They also add mechanical complexity and can lead to an expensive price for even the most basic models.

Some espresso machines eliminate the pump completely and instead make use of steam pressure to make espresso coffee machine home. This can result in over-extraction because the boiler that makes steam also warms the water to boil. Additionally these machines typically have to rebuild their pressure between cups, which takes time and energy.

A majority of best espresso machine under 500 machines utilize an rotary or a vibration pump. A vibration model utilizes a rotating disk to generate pressure, while a circular model pushes hot liquid through the ground at a high speed. Both models can make a great espresso, however Rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the part which heats the water to the ideal temperature for extraction. The steam that is created reaches the portafilter, which is the container that holds the espresso coffee grounds. It is then funneled into the cup. During this process, the steam creates pressure to push through the coffee grounds. This creates a layer crema on top. This is one of the main characteristics of a great espresso.

There are three types of espresso makers. They differ in the kind of pump they use and how hot the espresso is. There are different ways to control the brew and the size of the cup that can be produced by the machine.

The first espresso machines were steam-types. They used a single boiler to make steam and brew, however, the pressure they could generate was low - only two bars of atmospheric pressure maximum. This resulted in the coffee tasting burnt and bitter. This is the reason why Milanese producers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.

The most commonly used espresso machine is a semiautomatic that has an electric pump. These are the images people have when they imagine an espresso machine. Semi-automatic machines require you to grind and tamp the beans on your own The pump, however, regulates the water flow and pressure. This is a fantastic compromise between human control and mechanised consistency.

The Filter

Typically, espresso machines utilize filters to separate the grounds of coffee when they pass through the hot water. The filter is also an essential part of the machine's temperature control, as it helps prevent overheating.

It also improves flavor, as a filter can allow for a longer bloom time. This allows the beans to let their nuances out and provides an opportunity for a better extraction.

However, it is important to keep in mind that even a top espresso machines filter can make a terrible 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 espresso really taste good. The grouphead (also known as the brewhead) is where you put the portafilter - the thingy used to place the grounds of your coffee into while making espresso.

Steam-driven espresso machines make use of hot water heated in an airtight container to create steam. The steam then pushes hot water through coffee and espresso machine grounds under high pressure. These machines are cheaper and are easier for the user to maintain than pumps-driven models. They are however limited in their ability for creating the ideal conditions for brewing, as they operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

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