How Does Machine Espresso Work?

The machine espresso utilizes precise pressure and filter technology that is mind-blowing to create the coffee you love. 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 but the difference is in the pressure.

The Head of the Group

The group head is the portafilter you put in when making espresso. It is responsible for dispersing water into the portafilter before controlling the pressure that results from the extraction. There are many different types of group heads each with its own advantages and disadvantages. 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 include a mix of features, such as the E61 that is the classic choice among many baristas because of its ability to provide multiple benefits in one package.

As you can see from the photo above, the group head is fitted with a variety of notches. You can place your portafilter in these notches, then twist the head to lock it. There is also a gasket of rubber that resides inside the notches and helps create the seal when you insert your portafilter into the machine. The notches on the head allow for a precise position of the portafilter which is essential to ensure an efficient extraction.

The group head is not just able to allow you to insert your portafilter easily however, it also keeps a constant temperature. This is done by cycling hot water around the portafilter and through the brew-basket to ensure that the temperature is always at the right level for extraction. It is important to remember that even a slight variation can mean the difference between a great and a great espresso.

The Pump

The motorized pumps that are used in espresso machines that rotate provide the nine atmospheric bar pressure needed to extract espresso. This differs from manual piston machines which use levers. The pressure is created by drawing tap water from a reservoir, and pumping it through a heat exchanger prior being pumped through the ground coffee inside the group head.

Pumps tend to be less expensive and last for longer than piston-driven machines. However, both kinds of machines can degrade because of excessive use and poor cleaning. Pumps are also more complicated mechanically, which can increase prices of even simplest models.

Some espresso machines use steam pressure instead of a pump to brew espresso machine black friday. This could lead to over-extraction since the boiler that produces steam also heats the water until it comes to a boil. They also have to constantly rebuild their pressure between cups. This takes energy and time.

A majority of espresso machines utilize a rotary or vibration pump. A vibration model makes use of a vibrating disk to generate pressure, while the Rotary model pushes hot coffee through the ground at a rapid speed. Both models can make a great espresso, however rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the part that heats water to the optimal temperature for extraction. The resulting steam is then transferred to the portafilter which holds ground espresso beans and is then pumped into the cup. The steam causes pressure to push through the grounds of the coffee. This creates a layer crema that is then poured over. This is one of the main characteristics of a good espresso.

There are three distinct types of espresso machines, each with different types of pumps and the temperature of the brew. There are different ways to control the brew as well as the size of the cup that can be made by the machine.

The earliest espresso machines were steam-based. The first espresso home machine (writes in the official campusvirtual.newlink.es blog) machines were steam types. The coffee tasted bitter and burned. This is the reason Milanese makers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most common espresso maker is a semi-automatic one that has an electric pump. When people think of espresso makers machines, they picture these machines. With a semi-automatic espresso machine, you need to grind the beans and tamp them by hand. The pump is able to regulate the flow of water and pressure. This is a perfect compromise between human control and mechanized accuracy.

The Filter

Typically, espresso machines utilize filters to separate the grounds of the coffee as they go through the hot water. The filter is also an important part of the temperature control system since it helps prevent the machine from overheating.

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

It is important to remember that even the most efficient filter can make a bad cup of coffee. The quality espresso machine of the beans and the extraction, are still very important.

This is where the magic happens, it's what makes an espresso really taste good. The grouphead (also known as the brewhead) is where you place the portafilter, which is the thingy used to place the grounds of coffee into when making espresso.

In a steam-driven espresso machine, hot water is heated in an airtight container to create steam, which is then pushed through the grounds at high pressure. These types of machines tend to be less expensive and simpler to maintain than pumps-driven models. They are however limited in their ability to create the perfect conditions for brewing since they only operate with 1-1.5 bar of pressure. The perfect shot requires 9-10 bars.

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