9 Lessons Your Parents Taught You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso uses precision pressure and amazing filter technology to make the perfect cup of coffee. How exactly does it work?

In order to make espresso hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee. However, the pressure is the primary difference.

The Head of the Group

As the name implies the group head is the place you put your portafilter in when making espresso. It is responsible for dispersing the water into the portafilter before controlling the pressure of the resulting extraction. There are several different types of group head each with its own advantages and drawbacks. Some are focused on temperature stability, while others on pre-infusion capabilities, and still others are designed to control the lever. Some come with a combination of both, like the E61. This is a popular choice among baristas because it offers multiple advantages in a single package.

As you can see from the image above the group head has a number of notches. You can place your portafilter into these notches and twist the head to secure it. A gasket made of rubber is placed inside the notches, which helps make a seal when you insert your portafilter. The notches on the head permit an exact position of the portafilter which is crucial to ensure an efficient extraction.

The group head not only lets you to place your portafilter easily, but it also maintains a constant temperature. It does this by cycling hot water through the brew pan and around the portafilter, making sure that it's always at the correct temperature to extract. This is crucial, since even a few degrees can be the difference between a good and great espresso.

The Pump

Motorized pumps in espresso machines that rotate provide the nine atmospheric bar pressure that is required to extract espresso. This differs from manual piston machines which use levers. This pressure is built up by pumping water through a heat exchanger and then through the ground coffee.

Pumps are typically less expensive and last longer than piston-driven machines. However, both kinds of machines can deteriorate because of excessive use and insufficient cleaning. They also make mechanically complex that can lead to a high price tag on even the most basic models.

Certain espresso machines eliminate 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 to the point of boiling which can cause over-extraction. In addition these machines typically have to restore their pressure between cups, which takes time and energy.

Many espresso coffee machine home machines utilize either a rotary or vibration pump, with a vibration model using a vibrating disc to create pressure and a rotary model pushing hot water through the grounds under high speed. Both machines produce great espresso but rotary machines are more quiet, durable and less likely to break down.

The Boiler

The boiler is the part that heats the water to the ideal temperature to extract. The steam that is created is then directed to the portafilter, which is the container that holds the espresso coffee grounds. It is then poured into the cup. The steam generates enough pressure bean to cup espresso machine push the grounds of coffee through. This creates a layer crema on top. This is the hallmark of a good espresso.

There are three kinds of espresso machines, each having distinct pumps and brew temperature. There are many ways to control the brew and the size of cup that can be made 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. The modern espresso machine was developed by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most common espresso maker is a semi-automatic machine that has an electric pump. When people think of espresso machines, they picture these machines. Semi-automatic machines require you to grind and tamp the beans by yourself while the pump controls the flow of water and pressure. This is a great solution that combines human control with mechanized reliability.

The Filter

Espresso machines usually have a filter that separates the coffee grounds from the hot water. The filter is also a crucial component of the temperature control system because it stops the machine from overheating.

A filter can also help with flavor as it allows for a longer flowering period. This allows the beans to let their nuances out, and allows for better extraction.

It is important to keep in mind that even the most efficient filter can result in a bad cup of coffee. The quality of the beans, as well as the extraction, are still crucial.

It's here that the magic happens. This is what makes retro espresso machine taste so delicious. The grouphead (also called the brewhead) is where you place the portafilter, the thingy that you use to put the coffee grounds into, while making espresso.

Steam-driven espresso machines espresso machines make use of hot water that is heated in an airtight container to create steam. The steam then moves hot water through the grounds of coffee at high pressure. These kinds of machines are usually less expensive and easier to maintain than pumps-driven models. They are however limited to create the ideal brewing conditions as they only operate with 1-1.5 bar of pressure. The ideal shot requires 9-10 bars.

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