9 Things Your Parents Taught You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso utilizes precise pressure and incredible filter technology to produce the delicious coffee we enjoy. But how exactly does it work?

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

The Head of the Group

The group head is the portafilter is inserted when you are making espresso. It is responsible for dispersing the water into the portafilter, and controlling the pressure of the extraction. There are a variety of types of group head, each with their particular advantages and drawbacks. Some are designed to provide stability in temperature, while others are built to handle pre-infusion. Others are made to control the lever. Some include a combination like the E61. This is a favorite among baristas since it provides multiple benefits in one package.

As you can see in the photo above, the group head is equipped with several notches. You can place your portafilter into these notches and turn the head around to secure it. A gasket made of rubber is positioned inside the notches to help create a seal when you insert your portafilter. The notches on the head allow for an exact location of the portafilter which is essential for an even extraction.

The group head not only allows you to put in your portafilter easily however it also keeps the same temperature. This is done by cycling hot water around the portafilter and through the brew-basket, making sure the temperature is always right for extraction. This is important because just a few degrees could make the difference between excellent and great espresso.

The Pump

Unlike manual piston machines, which use a lever to pressurize water, the rotary espresso machines use motorized pumps to deliver the nine atmospheric bars of pressure that are required to extract espresso. This pressure is built up by pumping water through a heat exchanger and then through the ground coffee.

Pumps are generally less expensive than piston-driven machines espresso machines and tend to last longer. However, both types of machines may get damaged through overuse and lack of cleaning. Pumps are also more complex mechanically, and can add to prices of even simple models.

Some espresso machines do away with the pump entirely and utilize steam pressure to make espresso. This could lead to over-extraction since the boiler that produces steam also warms the water to boil. They also have to continuously rebuild their pressure between cups. This requires energy and time.

Many espresso machines utilize a vibration or rotary pump, which has a vibration model that uses a vibrating disc to create pressure and a rotary model pushing hot water through the grounds under high speed. Both machines can make excellent espresso however rotary machines tend to be quieter, more durable and less likely to break down.

The Boiler

The boiler is the element that heats water to the ideal temperature for extraction. The steam produced gets to the portafilter which holds the espresso grounds. It is then poured into the cup. The steam creates pressure to push through the grounds of the coffee. This results in a crema on top of the espresso. This is a sign of a good espresso.

There are three different types of espresso machines, each having distinct pumps and the temperature of the brew. There are a variety of ways in which the brew can be controlled and the size of the cup that the machine can make.

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

The most common espresso machine is a semiautomatic with an electric pump. These are what people imagine when they think of an espresso maker. Semi-automatic espresso machine machines require you to grind and tamp the beans yourself, but the pump regulates the water flow and pressure. This is an excellent combination of human control and mechanized accuracy.

The Filter

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

It also enhances flavor as a filter allows for a longer bloom time. This allows the beans to release their flavors, and allows for better extraction.

However it is crucial to remember that even a good filter can produce a bad cup of coffee espresso machine, because the quality espresso machine of the beans and extraction is essential.

This is where the magic happens, it's the thing that makes an best small espresso machine really taste good. The grouphead (also called the brewhead) is where you place the portafilter, which is the thingy used to place the coffee grounds in, when making espresso.

In a steam-driven espresso machine hot water is heated in an airtight tank to create steam. This is then pushed through the grounds under high pressure. These kinds of machines tend to be cheaper and easier to maintain than pump-driven models. They are however limited to create the perfect brewing conditions as they only operate with 1-1.5 bar of pressure. The ideal shot requires 9-10 bars.

In recent years, espresso machines powered by compressed air-pump are becoming increasingly popular. They use an air-compressor to push hot water across the ground. They are also more mobile than steam-driven electric espresso machines.