How Does Machine Espresso Work?

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

To make espresso, hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee. However the pressure is the main difference.

The Group Head

The name implies, the group head is where you put your portafilter in 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 distinct advantages and drawbacks. Some focus on temperature stability, while others on pre-infusion capabilities, while others are designed to control the lever. Some include a combination such as the E61. This is a preferred choice for baristas because it offers multiple advantages in one package.

As you can see in the above photo, the group head has several notches to place your portafilter before twisting it by hand to lock it in. There is also a gasket of rubber which is located inside the notches to help create a seal when you insert your portafilter into the machine. The notches permit precise placement of the portafilter. This is essential for an efficient extraction.

The group head not only lets you to put in your portafilter easily however it also keeps the temperature at a constant level. It does this by cycling hot water through the brew pan and around the portafilter, ensuring that it's always at the right temperature to extract. This is vital, because even a few degrees can mean the difference between excellent and great espresso.

The Pump

In contrast to manual piston machines which rely on a lever to pressurize water, rotating cheap espresso machine machines rely upon motorized pumps that provide the nine atmospheric bars of pressure required to extract espresso. The pressure builds up by drawing tap water from a reservoir and pumping it through a heat exchanger prior it is shot through the ground coffee inside the group head.

Pumps are typically less expensive and last for longer than piston-driven machines. However, both types of machines can deteriorate due to excessive use and poor cleaning. Pumps are also more complicated mechanically, which can increase prices of even most basic models.

Some espresso machines make use of steam pressure instead of a pump to brew espresso. The disadvantage of this is that the boiler that produces steam also raises the temperature of water to boiling and can result in over-extraction. The machines must also continually rebuild their pressure between cups. This takes energy and time.

Many italian espresso machines machines employ the rotary or vibration pump, with a vibrating model that uses a vibrating disc that generates the pressure, and a rotary model pushing hot water through the grounds at high speed. Both models can produce an excellent espresso, but Rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the one that is used to heat the water to the ideal temperature to extract. The steam produced is then directed to the portafilter, which is a container for espresso grounds. It is then pumped into the cup. In this process, the steam creates pressure and pushes through the grounds of the coffee. This creates a foam on the top of the best budget espresso machine. This is a sign of a great espresso.

There are three types of espresso makers. They differ in the kind of pump they use and the degree of heat that the coffee is. There are a variety of ways in which the brew can be controlled, as well as the size of the cup that the machine is capable of making.

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

The most commonly used mini espresso machine machine is a semiautomatic with an electric pump. These are what people imagine when they think of an best espresso machine under 200 machine. Semi-automatic machines require you to grind and tamp the beans by yourself while the pump controls the water flow and pressure. This is an excellent compromise between human touch and the mechanised quality.

The Filter

Typically, espresso machines use a filter to separate out the grounds of the coffee as they go through the hot water. The filter is also an essential component of the machine's temp control, since it helps to prevent overheating.

It also enhances flavor, as a filter allows for a more prolonged bloom phase. This allows the beans to release their flavor and allows for better extraction.

It is important to remember that even the most efficient filter could result in a poor cup of coffee. The quality of the beans, and the extraction process are still crucial.

This is where the magic happens, it's what makes an espresso really taste good. The grouphead, sometimes called the brewhead, is where the portafilter (the thing you put the coffee ground into) sits when you're making espresso.

Steam-driven espresso machines make use of hot water that is heated inside an airtight container to produce steam. The steam then pushes hot water through the coffee grounds under high pressure. These types of machines are typically less expensive and easier to maintain than pump-driven models. However, they are limited in their ability to create the perfect conditions for brewing, because they operate at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bars.

In recent years, compressed air pump-driven espresso machines have been gaining popularity. They use an air-compressor to push hot water across the ground and are more mobile than electric steam-driven espresso machines.