The 9 Things Your Parents Teach You About Machine Espresso

How Does machine espresso (Learn Even more) Work?

Machine espresso uses precision pressure and mind-blowing filter technology to make the coffee we love. How does it work exactly?

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

The Group Head

The group head is the portafilter is inserted when you are making espresso. It is responsible for dispersing water into the portafilter and then controlling the pressure that results from the extraction. There are many different kinds of group heads, each with their particular advantages and drawbacks. Some are specifically designed for temperature stability while others are designed to handle pre-infusion. Others are made to control the lever. There are even some that come with a range of features, such as the E61 that is to be the most popular among baristas for its ability to offer multiple perks in one package.

As you can see from the above photo, the group head is equipped with several notches. You place your portafilter in these notches, then twist the head to lock it. A rubber gasket is located inside the notches to help make a seal when you insert your portafilter. The notches permit an exact placement of the portafilter. This is essential for an efficient extraction.

The group head does not just allow you to place your portafilter easily however, it also keeps a constant temperature. It does this by cycling hot water through the brew basket, and around the portafilter to ensure that it is always at the correct temperature for extraction. This is important because even a few degrees can mean the difference between good and great espresso.

The Pump

In contrast to piston machines that are manually operated, which rely on a lever to pressurize water, rotating espresso machines rely upon motorized pumps to provide the nine atmospheric bars of pressure necessary for espresso extraction. This pressure builds up by drawing tap water from a reservoir, and pumping it through a heat exchanger prior being pushed through the ground coffee and espresso maker inside the group head.

Pumps are typically less expensive and last longer than piston-driven machines. However, both kinds of machines can degrade due to overuse and insufficient cleaning. Pumps are also more complicated mechanically, which could increase the cost of even simpler models.

Some espresso machines use steam pressure instead of a pump to brew espresso. This could lead to over-extraction since the boiler that produces steam also warms the water to boil. In addition these machines typically have to restore their pressure between cups, which takes time and energy.

Many espresso machines use either a vibration or rotary pump. A vibration model makes use of a vibrating disk to generate pressure, while a rotary model pushes hot water through the ground at a high speed. Both machines can produce excellent espresso but rotary machines are more stable, quieter and less likely to break down.

The Boiler

The boiler is the element which heats the water to the ideal temperature for extraction. The resultant steam then reaches the portafilter which holds the ground espresso maker coffee, and is then pumped into the cup. During this process the steam generates enough pressure to push the grounds of the coffee through. This results in a crema on the top of the espresso. This is the hallmark of a good espresso.

There are three different types of espresso machines, each with different pumps and the temperature of the brew. There are different ways in which the brew can be controlled and the size of the cup the maker can create.

The first espresso machines were steam-based. The earliest espresso machines were steam types. The coffee tasted bitter and burnt. The modern espresso machine was developed by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most common espresso machine is a semiautomatic 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 on your own however the pump controls the flow of water and pressure. This is a perfect compromise between human control and mechanized accuracy.

The Filter

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

A filter also helps with flavor, as it permits a longer flowering phase. This lets the beans release their flavor and allows for a better extraction.

It is important to remember that even the best ground coffee for espresso machine filter can result in a bad cup of coffee. The quality of the beans, as well as the extraction, are still very important.

This is where the magic happens, it's what makes an espresso really taste good. The grouphead, also called the brewhead, is where the portafilter (the container you place the coffee ground into) is placed when making espresso.

Steam-driven espresso machines use hot water that is heated inside an airtight container to make steam. The steam then pushes hot water into the coffee grounds under high pressure. These types of machines are usually less expensive and easier to maintain than pump-driven models. They are however limited to create the ideal conditions for brewing since they only 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 utilize an air compressor to push hot water into the grounds, and are far more portable than steam-driven electric machines.