How Does Machine Espresso Work?

Machine espresso makes use of precise pressure and incredible filter technology to produce the coffee we love. What exactly is it?

To make an espresso hot water is pushed under 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 implies the group head is where you insert your portafilter when making espresso. It disperses the water into the portafilter, and regulates the pressure of extraction. There are many different types of group heads, each with its own advantages and disadvantages. Some focus on temperature stability, whereas others on pre-infusion capabilities, while others are designed to control the lever. Some are a combination, such as the E61. This is a popular choice among baristas because it offers multiple benefits in one package.

As you can see in the above image The group head features numerous notches that you can put your portafilter, then twist it by hand to secure it. A rubber gasket is located inside the notches to help make a seal when you insert your portafilter. The notches allow for an exact placement of the portafilter. This is vital for buy Espresso Machine an efficient extraction.

Apart from allowing you effortlessly insert your portafilter the group head is responsible for maintaining an even temperature. It does this by cycling hot water through the brew container and around the portafilter to ensure that it's always at the right temperature for extraction. This is crucial, since just a few degrees could make the difference between excellent and great espresso.

The Pump

The motorized pumps in espresso machines rotary provide nine atmospheric bar pressure needed for espresso extraction. This differs from manually operated piston machines that employ levers. The pressure builds by drawing tap water from a reservoir and pumping it through a heat exchanger prior to being shot through the ground coffee in the group head.

Pumps tend to be cheaper and last longer than piston-driven machines. However, both types of machines can deteriorate because of excessive use and insufficient cleaning. Pumps are also more complex mechanically, which could increase prices of even most basic models.

Some espresso machines use steam pressure instead of a pump for brewing espresso. The disadvantage of this is that the boiler that produces steam also increases the temperature of water to the point of boiling which can cause over-extraction. They also have to constantly rebuild their pressure between cups. This requires energy and time.

A large majority of espresso machines employ an rotary or a vibration pump. A vibration model utilizes a rotating disk to generate pressure, whereas a Rotary model pushes hot coffee through the ground at high speed. Both machines can make great espresso, however rotary machines are more stable, quieter and less likely to break down.

The Boiler

The boiler will heat the water to a temperature that is ideal bean to cup espresso machine extract. The resulting steam reaches the portafilter which holds the ground espresso coffee and is then funneled down into the cup. During this process the steam causes 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 great espresso.

There are three distinct types of espresso machines, each with a different type of pump and the temperature of the brew. There are various ways in which the brew could be controlled and the dimensions of the cup the maker can create.

The earliest espresso machines were steam type. The earliest espresso machines were steam types. This led to the coffee tasting bitter and burnt. The modern espresso machine was developed by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most well-known decent espresso machine maker is a semiautomatic machine that has an electric pump. This is what people envision when they imagine an Cafe espresso machine machine. 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 great compromise between human control and mechanized accuracy.

The Filter

Espresso machines typically have filters that separate the grounds of the coffee and espresso machine from the hot water. The filter is also a vital element of the temperature control system, as it keeps the machine from overheating.

It also aids in flavor, since a filter can allow for a longer bloom time. This allows beans to release their flavors and provides an opportunity for better extraction.

However, it is important to remember that even a great filter can result in a poor cup of coffee as the quality of the beans and extraction is still important.

It's in this area that the magic takes place. This is what makes espresso taste so good. The grouphead, sometimes referred to as the brewhead, is where the portafilter (the thing you put the ground coffee into) is located when you're making espresso.

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

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