The Most Negative Advice We've Ever Received On Machine Espresso

How Does Machine Espresso Work?

Machine espresso makes use of precise pressure and mind-blowing filter technology to make the delicious coffee we enjoy. How does it work exactly?

Espresso is made by forcing hot water under high pressure through finely ground coffee. The process is similar to that of making drip coffee. However it is the pressure that makes the main difference.

The Group Head

The group head is the portafilter you put in when making espresso. It is responsible for dispersing the water into the portafilter and then controlling the pressure of the extraction. There are numerous kinds of group heads each with distinct advantages and drawbacks. Some focus on temperature stability, while others on pre-infusion options, and others are designed to control the lever. Some come with a combination of both, like the E61. This is a preferred choice for baristas as it provides a variety of advantages in a single package.

As you can see in the photo above The group head features many notches in which you can put your portafilter, then twist it by hand to lock it in. There is also a gasket made of rubber that resides inside the notches and helps create an airtight seal when you insert your portafilter into the machine. The notches permit precise placement of your portafilter. This is crucial to ensure a consistent extraction.

Apart from allowing you easily place your portafilter in, the group head is also responsible for maintaining a consistent temperature. It does this by cycling hot water through the brew basket and around the portafilter, making sure that it is always at the correct temperature to extract. It is important to remember that even a slight variation can mean the difference between a decent and a great espresso.

The Pump

The motorized pumps used in espresso machines that rotate provide the nine atmospheric bar pressure required for espresso extraction. This is different from manual piston machines that use levers. The pressure is created by pumping water through a heat exchanger and then through the ground coffee.

Pumps tend to be less expensive and last longer than piston-driven machines. However, both types of machines are susceptible to degrading due to excessive use and poor cleaning. Pumps are also more complicated mechanically, which can raise the cost of even the simple models.

Some espresso machines do away with the pump completely and instead utilize steam pressure to make espresso. The downside is that the boiler that produces steam also raises the temperature of the water until it reaches boiling which can cause over-extraction. In addition these machines are often required to rebuild their pressure between cups, which takes time and energy.

Many espresso machines make use of an rotary or vibrating pump, which has a vibration model using a vibrating disc that generates the pressure, and a rotary model pushing hot water through the grounds under high speed. Both machines can make excellent espresso but rotary machines are more stable, quieter and less likely to fail.

The Boiler

The boiler is the part that heats water to the ideal temperature to extract. The steam that is produced reaches the portafilter containing ground espresso beans and is then pumped down into the cup. During this process, steam creates pressure to push through the grounds of the coffee. This produces a layer of crema that is then poured over. This is one of the hallmarks 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 espresso is. There are a variety of ways to control the brew as well as the size of cup that can be made by the machine.

The first espresso machines were steam types. They used one boiler to make both steam and brew, but the pressure they could create was minimal - two bars of atmospheric pressure, at most. This led to the coffee tasting bitter and burnt. This is why Milanese producers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.

The most well-known espresso machine is a semiautomatic with an electric pump. These are the images people have when they think of an espresso machine. Semi-automatic machines require you to grind and tamp your beans yourself however the pump controls the water flow and pressure. This is a great compromise between the human touch and the mechanized consistency.

The Filter

Espresso machines usually have filters that separate the grounds of coffee from hot water. The filter is also a vital component of the machine's temperature control, since it stops overheating.

A filter also helps with flavor because it allows for a longer flowering phase. This lets the beans release their flavor and allows for a better extraction.

It is important to remember that even the best filter can result in a bad cup of coffee.  espresso machines uk  of the beans, as well as the extraction, remain crucial.

It's in this area that the magic occurs. This is the reason why espresso tastes so good. The grouphead (also called the brewhead) is where you place the portafilter, which is the thingy which you put the coffee grounds in, when making espresso.

In the steam-driven espresso machine hot water is heated in an airtight tank to create steam. Steam then pushes the hot water through the grounds with high pressure. They are less expensive and easier to maintain than pumps-driven models. However, they are not as efficient in their capacity to create the perfect brewing conditions since they operate at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bar.

In recent times, espresso machines powered by compressed air-pump are becoming increasingly popular. They use an air compressor to force hot water through the grounds, and are far more portable than steam-driven electric machines.