The 9 Things Your Parents Teach You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso makes use of precise pressure and mind-blowing filter technology to create the coffee we love. What exactly is it?

Espresso is produced by pushing hot water under pressure through finely-ground coffee. The process is similar to making drip coffee. However it is the pressure that makes the main difference.

The Head of the Group

As the name implies the group head is where you place your portafilter when brewing espresso. It disperses the water into the portafilter and regulates the pressure during the extraction. There are many different types of group heads each with its own advantages and disadvantages. Some are focused on temperature stability, others on pre-infusion capabilities, and still others are designed to control the lever. Some are a combination, such as the E61. This is a favorite among baristas because it offers multiple benefits in a single package.

As you can see from the photo above the head of the group has a number of notches. You can place your portafilter in these notches, then twist the head to lock it. A rubber gasket is located inside the notches to help create a seal as you insert your portafilter. The notches allow for the precise placement of the portafilter. This is crucial to ensure an efficient extraction.

Aside from allowing you to effortlessly insert your portafilter the group head is also responsible for maintaining a consistent temperature. It does this by cycling hot water through the brew basket, and around the portafilter, ensuring that it's always at the correct temperature for extraction. This is crucial, since even a few degrees can be the difference between a good and great espresso.

The Pump

The motorized pumps that are used in best espresso maker machines rotary provide nine atmospheric bar pressure required to extract espresso. This differs from manual piston machines that use levers. The pressure is built by pumping water through a heat exchanger and then through the ground coffee.

Pumps are generally less expensive than piston-driven models, and they tend to last longer, however both types of machines may degrade with overuse and insufficient cleaning. They also add mechanical complexity and can lead to costly prices for even the simplest models.

Certain espresso machines can eliminate the pump entirely and use steam pressure to brew espresso. This can result in over-extraction because the boiler that makes steam also heats the water until it comes to a boil. The machines also need to constantly rebuild their pressure in between cups. This takes energy and time.

Many mini espresso machine machines make use of either a vibration or rotary pump. A vibration model utilizes a vibrating disk to generate pressure, whereas the rotating model pushes hot water through the ground at a fast speed. Both machines produce great espresso but rotary machines are more quiet, durable and less likely to fail.

The Boiler

The boiler is the part that heats water to an optimal temperature for extraction. The resulting steam reaches the portafilter, which contains ground espresso beans and is then pumped down into the cup. The steam is able to create enough pressure to push the grounds of coffee through. This creates a layer crema that is then poured over. This is one of the main characteristics of a good espresso.

There are three kinds of espresso machines, each having a different type of pump and the temperature of the brew. There are different ways that the brew may be controlled, as well as the size of the cup the maker can create.

The first espresso machines were steam-types. They had a single boiler to make steam and brew, however the pressure they were able to create was minimal - two bars of atmospheric pressure maximum. The coffee tasted bitter and burnt. This is why Milanese makers Luigi Bezzerra and Desiderio Pavoni developed the modern espresso machine.

The most well-known espresso machine is a semiautomatic one with an electric pump. When people think of espresso machines, they imagine these machines. Semi-automatic machines require you to grind and tamp the beans by yourself however the pump controls the water flow and pressure. This is a great compromise between the human touch and the mechanised accuracy.

The Filter

Typically, espresso machines have a filter to separate out the grounds of coffee as they move through the hot water. The filter is also a vital element of the machine's temperature control, as it prevents overheating.

It also enhances flavor, as it allows for a longer bloom time. This allows beans to release their flavors and provides an opportunity for better extraction.

However it is crucial to remember that even a good filter can result in a poor cup of coffee, since the quality of the beans and extraction are vital.

It's here that the magic takes place. This is the reason why espresso tastes so good. The grouphead (also called the brewhead) is where you place the portafilter, the thingy used to place the coffee grounds in, while making espresso.

Steam-driven espresso machines use hot water that is heated inside an airtight container to produce steam. The steam then moves hot water through the grounds of coffee under high pressure. These machines are cheaper and easier for the owner to maintain than pumps-driven models. However, they are limited in their capacity to create the ideal conditions for brewing since they are only operating at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bar.

In recent years, espresso machine small machines driven by a compressed air pump have become increasingly popular. They use an air compressor to push hot water across the ground and are much more mobile than electric steam-driven espresso machines.