10 Tell-Tale Warning Signs You Need To Get A New Machine Espresso

How Does Machine Espresso Work?

Machine espresso employs precise pressure and amazing filter technology to make the delicious coffee we enjoy. What exactly is it?

Espresso is created by forcing hot water under pressure through finely-ground coffee. The process is similar to that of making drip coffee. However, the pressure is the major difference.

The Group Head

As the name suggests, the group head is where you place your portafilter while brewing espresso. It disperses water into the portafilter, and regulates the pressure of extraction. There are many different kinds of group heads, each with their particular advantages and drawbacks. Some focus on temperature stability, while others on pre-infusion capabilities, while others are designed to control the lever. Some are a combination, like the E61. This is a favorite among baristas because it offers multiple advantages in a single package.

As you can see from the photo above the head of the group is equipped with several notches. The portafilter is placed inside these notches, and then twist the head to secure it. A gasket made of rubber is placed within the notches to create a seal when you insert your portafilter. The notches permit an exact placement of the portafilter. This is essential for an even extraction.

The group head is not just able to allow you to place your portafilter easily but also maintains a constant temperature. This is accomplished by cycling hot water around the portafilter and through the brew-basket, making sure that the temperature is at the right level for extraction. This is important, as even a few degrees can make the difference between excellent and great espresso.

The Pump

Motorized pumps in rotary espresso machines supply the nine atmospheric bars of pressure required for espresso extraction. This is different from manually operated piston machines that employ a lever. The pressure is created by drawing tap water from a reservoir, and pumping it through a heat exchanger before being pumped through the ground coffee inside the group head.

Pumps are generally less expensive than piston-driven models, and they tend to last longer, however both types of machine can get damaged through overuse and lack of cleaning. Pumps are also more complicated mechanically, and can add to the cost of even simpler models.

Some espresso machines make use of steam pressure instead of a pump for brewing espresso. The disadvantage of this is that the same boiler that produces steam also increases the temperature of water to the point of boiling and can result in over-extraction. In addition the machines often have to rebuild their pressure between cups, which takes time and energy.

Many espresso machines make use of an rotary or a vibration pump. A vibration model uses the vibrating disk to create pressure, while a circular model pushes hot liquid through the ground at a high end espresso machine speed. Both types of machines can make a great espresso, but Rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the component that heats the water to the optimal temperature for extraction. The steam created will eventually reach the portafilter, which is the container that holds the espresso coffee grounds. It is then pumped into the cup. During this process the steam is able to create enough pressure to push the coffee and espresso machine grounds through. This creates a crema on the top of the espresso. This is the hallmark of a good espresso.

There are three kinds of espresso makers. They differ in the kind of pump they use and the degree of heat that the coffee is. There are many ways to control the brew and the size of the cup that can be made by the machine.

The first espresso machines were steam-based. The first retro Espresso Maker machines were steam-type machines. This led to the coffee tasting bitter and burnt. The modern espresso machine was invented by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most common espresso maker is a semi-automatic machine with an electric pump. These are the things people think of when they think of an espresso machine. Semi-automatic machines require you to grind and tamp the beans on your own however the pump controls the water flow and pressure. This is a great compromise between human control and mechanized consistency.

The Filter

Typically, espresso machines employ filters that separate the grounds of the coffee as they go through the hot water. The filter is also an essential part of the machine's temperature control, as it helps prevent overheating.

It also aids in flavor, since a filter allows for a more prolonged bloom phase. This lets the beans release their nuances, and allows for better extraction.

It is important to remember that even the best filter can result in a bad cup of coffee. The quality of the beans as well as the extraction, are still crucial.

This is where the magic happens, and it's what makes espresso taste great. The grouphead (also known as the brewhead) is where you put the portafilter, the device that you use to put 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. Steam is then pushed through the grounds at high pressure. These types of machines are typically less expensive and simpler to maintain than pumps-driven models. They are however limited in their ability for creating the ideal conditions for brewing as they only operate with 1-1.5 bar of pressure. The ideal shot requires 9 bar espresso machine-10 bars.

In recent times, espresso machines powered by compressed air-pump are becoming increasingly popular. They utilize an air compressor to force hot water into the ground. They are also more mobile than steam-driven electric espresso machines home machines.