9 . What Your Parents Teach You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso makes use of precise pressure and mind-blowing filter technology to create the perfect cup of coffee. What exactly is it?

In order 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 major difference.

The Group Head

As the name implies, the group head is where you put your portafilter in when brewing espresso. It is responsible for dispersing the water into the portafilter, and controlling the pressure of the resulting extraction. There are many different kinds of group head, each with their own advantages and disadvantages. Some focus on temperature stability, others on pre-infusion features, and others are designed to control the lever. Some include a combination such as the E61. This is a popular choice among baristas since it provides multiple benefits in one package.

As you can see in the image above the group head is made up of several notches where you place your portafilter and then twist it with your hands to lock it in. A gasket made of rubber is positioned within the notches to create a seal when you insert your portafilter. The notches on the head permit a precise location of the portafilter which is vital to ensure an even extraction.

Apart from allowing you easily insert your portafilter, the group head is also responsible for maintaining a consistent temperature. This is achieved by cycling hot water around the portafilter and through the brew-basket, making sure that the temperature is constant to extract the coffee. This is important, as even a few degrees can make the difference between excellent and great espresso.

The Pump

In contrast to manual piston machines which rely on a lever to pressurize water, rotary espresso machines rely on motorized pumps to provide the nine atmospheric bars of pressure that are required to extract espresso. This pressure is built up by pumping water through a heat exchanger and then through the ground coffee.

Pumps are generally more affordable and last longer than piston-driven machines. However, both types of machines are susceptible to degrading because of frequent use and poor cleaning. They also add mechanical complexity that can lead to costly prices for even the most basic models.

Some espresso machines make use of steam pressure instead of a pump to make espresso. The disadvantage of this is that the same boiler that produces steam also increases the temperature of the water to the point of boiling which can cause excessive extraction. The machines must also continually rebuild their pressure between cups. This requires energy and time.

Many espresso machines employ an rotary or vibrating pump, which has a vibration model that uses a vibrating disc to generate the pressure and the rotary model pushing hot water through the grounds at high speed. Both machines produce great espresso coffee maker but rotary machines are more stable, quieter and less likely to break.

The Boiler

The boiler is what makes the water warm to the perfect temperature for extraction. The resulting steam reaches the portafilter, which contains ground espresso beans and is then pumped into the cup. During this process the steam is able to create enough pressure to push the grounds of the coffee through. This creates a foam on top of the espresso. This is the hallmark of a good espresso.

There are three types of espresso machine black friday makers, which differ in the type of pump they employ and how hot the brew is. There are various ways that the brew may be controlled and the size of the cup that the machine is capable of making.

The earliest espresso machines were steam types. The earliest espresso machines were steam-type machines. The coffee tasted bitter and burned. The modern espresso machine was invented by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most common espresso maker is a semi-automatic machine that has 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 yourself however the pump controls the water flow and pressure. This is a fantastic combination of human control and mechanised consistency.

The Filter

Typically, best cheap espresso machine machines use filters that separate the coffee grounds as they pass through the hot water. The filter is also an essential element of the temperature control system, because it stops the machine from overheating.

A filter can also help with flavor, as it permits a longer flowering period. This allows the beans to release their nuances and gives an opportunity to improve extraction.

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

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

Steam-driven espresso machines use hot water heated in an airtight container to create steam. The steam then pushes hot water through the grounds of coffee under high pressure. These types of machines are usually less expensive and easier to maintain than pumps-driven models. They are however limited for creating the ideal 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 powered by compressed air-pump are becoming increasingly popular. They use an air compressor to push hot water into the grounds, and are far more portable than electric steam-driven machines.