Maisie Birdwood

How Does Machine Espresso Work?

Machine espresso employs precise pressure and amazing filter technology to make the perfect cup of coffee. What exactly is it that makes it work?

Espresso is produced by pushing hot water at high pressure through finely ground coffee. The process is similar to making drip coffee but the major difference is in the pressure.

The Head of the Group

As the name suggests the group head is where you put your portafilter in when making espresso. It disperses water into the portafilter, and controls the pressure of the extraction. There are many different types 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. There are also some that contain a variety 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 photo The group head features many notches in which you can place your portafilter and then twist it manually to secure it. There is also a rubber gasket that is a part of the notches and helps to create an airtight seal when you insert your portafilter into the machine. The notches permit an exact placement of the portafilter. This is essential for a consistent extraction.

The group head not only allows you to insert your portafilter easily however, it also keeps the temperature at a constant level. It does this by cycling hot water through the brew basket and around the portafilter, making sure that it's always at the correct temperature to extract. It is important to remember that even a few degree variation can mean the difference between a great and a great espresso.

The Pump

The motorized pumps in rotary espresso machines supply the nine atmospheric bar pressure required for espresso extraction. This differs from manual piston machines that rely on levers. The pressure builds up by drawing tap water from a reservoir, and pumping it through a heat exchanger prior it is shot through the ground coffee in the group head.

Pumps are generally more affordable and last longer than piston-driven machines. However, both kinds of machines may degrade due to excessive use and poor cleaning. Pumps are also more complicated mechanically, and can add to the cost of even simpler models.

Some espresso machines make use of steam pressure instead of a pump for brewing espresso. This could lead to over-extraction since the boiler that makes steam also heats the water until it comes to a boil. In addition, these machines frequently have to rebuild their pressure between cups, which takes time and energy.

Many espresso machines make use of an rotary or vibrating pump, which is a vibration model using a vibrating disc to generate the pressure, and rotating models that push hot water through the grounds under high speed. Both machines produce great espresso however rotary machines tend to be more stable, quieter and less likely to break.

The Boiler

The boiler is the element that heats water to the optimal temperature to extract. The resultant steam then reaches the portafilter that contains the ground best espresso machine coffee and gets funnelled down into the cup. The steam creates pressure and pushes through the grounds of the coffee and espresso maker. This results in a layer crema on top. This is the hallmark of a great espresso.

There are three different types of espresso machines, each having a different type of pump and brew temperature. There are different ways to control the amount of brew, as well as the size of cup that can be made by the machine.

The first espresso machines were steam types. The earliest italian espresso machine Espresso Machines (minecraftcommand.Science) machines were steam types. The coffee tasted bitter and burned. The modern espresso machine was developed by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used cheap espresso machine maker is a semi-automatic machine that has an electric pump. This is what people envision when they think of an espresso machine. Semi-automatic machines require you to grind and tamp the beans yourself however the pump controls the flow of water and pressure. This is a great compromise between the human touch and mechanized accuracy.

The Filter

Typically, espresso machines have filters to separate the grounds of coffee when they pass through the hot water. The filter is also an important part of the temperature control system, since it helps prevent the machine from overheating.

A filter can also help with flavor since it allows for a longer flowering period. This lets the beans release their flavor and allows for better extraction.

However, it is important to remember that even a high-quality filter can make a terrible cup of coffee as the quality of the beans and extraction is still crucial.

It's here that the magic occurs. This is what makes espresso taste so good. The grouphead (also called the brewhead) is where you place the portafilter, the thingy which you put the grounds of your coffee into while making espresso.

In the steam-driven espresso machine hot water is heated in an airtight container to produce steam, which is then pushed through the grounds at high pressure. These types of machines are usually less expensive and easier to maintain than pump-driven models. However, they are not as efficient in their capacity to create the ideal conditions for brewing 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 push hot water through the ground, and are more mobile than electric steam-driven espresso machines.