How Does Machine Espresso Work?

Machine espresso utilizes precise pressure and mind-blowing filter technology to create the delicious coffee we enjoy. How does it work exactly?

Espresso is produced by pushing hot water at 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 name implies, the group head is where you put your portafilter in when making espresso. It disperses the water into the portafilter, and then regulates the pressure of extraction. There are various kinds of group heads, each with their unique advantages and drawbacks. Some are designed to provide stability in temperature, while others are specifically designed to handle pre-infusion. Others are made to control the lever. Some include a combination such as the E61. This is a preferred choice for baristas since it provides multiple benefits in a single package.

As you can see in the above photo The group head features several notches where you put your portafilter, then twist it manually to secure it. A rubber gasket is located inside the notches, which helps create a seal while you insert your portafilter. The notches permit the precise placement of the portafilter. This is crucial for an accurate extraction.

The group head does not just allow you to put in your portafilter easily however it also keeps an even temperature. It does this by circulating hot water through the brew basket, and around the portafilter to ensure that it is always at the right temperature to extract. It is important to note that even a small differences can make the distinction between a great and a great espresso.

The Pump

The motorized pumps used in rotary espresso machines provide the nine atmospheric bars of pressure required to extract espresso. This differs from manual piston machines which use a lever. The pressure builds by drawing tap water from a reservoir and pumping it through a heat exchanger prior being pumped through the ground coffee inside the group head.

Pumps tend to be less expensive than piston-driven machines and tend to last longer, although both types of machines may get damaged through overuse and lack of cleaning. They also add mechanical complexity which can result in costly prices for even the most basic models.

Certain espresso maker barista machines utilize steam pressure instead of a pump in order to brew travel espresso maker. The downside is that the same boiler that produces steam also raises the temperature of water to the point of boiling which could lead to excessive extraction. The machines must also constantly rebuild their pressure in between cups. This requires energy and time.

A majority of espresso machines use an rotary or vibrating pump, which has a vibration model using a rotating disc to create pressure and a rotary model pushing hot water through the grounds at high speed. Both machines can produce excellent espresso, however rotary machines are more stable, quieter and less likely to break.

The Boiler

The boiler will heat the water to the right temperature to extract. The resulting steam reaches the portafilter which holds ground espresso beans and gets funnelled down into the cup. During this process the steam generates enough pressure to push the grounds of the coffee through. This creates a crema on the top of the espresso. This is one of the main characteristics of a good cheap espresso machine.

There are three types of espresso makers, and they differ in the type of pump they employ and the degree of heat that the brew is. There are various 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 types. This resulted in the coffee tasting burnt and bitter. This is the reason Milanese makers Luigi Bezzerra and Desiderio Pavoni invented the modern barista espresso Coffee Machine machine.

The most commonly used espresso maker is a semi-automatic machine that has an electric pump. These are what people imagine when they imagine an espresso machine. If you have a semi-automatic machine you need to grind the beans and tamp them yourself but the pump regulates the flow of water and pressure. This is an excellent compromise between human touch and the mechanized quality.

The Filter

Typically, espresso machines for home machines utilize a filter to separate out the grounds of the coffee as they go through the hot water. The filter is also an essential element of the machine's temperature control, since it helps to prevent overheating.

Filters also aid in flavor because it allows for an extended flowering time. This allows the beans to release their nuances, and also allows for better extraction.

It is important to keep in mind that even the most efficient filter can produce a bad cup of coffee. The quality of the beans and the extraction process, remain crucial.

It's here that the magic happens. This is the reason why espresso tastes so good. The grouphead (also known as the brewhead) is where you put the portafilter - the thingy that you use to put the grounds of your coffee into when making espresso.

In a steam-driven espresso machine, hot water is heated in an airtight tank to create steam, which is then pushed through the grounds at a high pressure. These types of machines are typically less expensive and easier to maintain than pumps-driven models. However, they are not as efficient in their ability to create the ideal brewing conditions, because they operate at 1-1.5 bars of pressure. While the perfect shot requires 9-10 bars.

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