Nine Things That Your Parent Teach You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso uses precision pressure and mind-blowing filter technology to make the perfect cup of coffee. How does it work exactly?

In order to make best espresso maker hot water is pushed under pressure through finely ground coffee. The process is similar to that of making drip coffee. However the pressure is the primary difference.

The Group Head

The name implies the group head is where you place your portafilter while making espresso. It is responsible for dispersing the water into the portafilter and controlling the pressure that results from the extraction. There are several different types of group head each with its own advantages and drawbacks. Some focus on temperature stability, while others on pre-infusion capabilities, while others are designed to control the lever. Some contain a variety of features, like the E61 one, which is the most popular choice among baristas because of its ability to offer multiple perks in one package.

As you can see from the image above the head of the group is fitted with a variety of notches. You place your portafilter in these notches and then twist the head to lock it. A gasket made of rubber is placed in the notches to create a seal when you insert your portafilter. The notches allow for an exact placement of the portafilter. This is essential for an even extraction.

In addition to allowing you easily connect your portafilter, the group head is responsible to ensure that the temperature remains even. It does this by cycling hot water through the brew pan and around the portafilter to ensure that it is always at the right temperature to extract. It is important to remember that even a few degree difference can make the difference between a good and a excellent espresso.

The Pump

Contrary to manual piston machines that use a lever to pressurize water, rotating espresso machines rely upon motorized pumps to provide the nine atmospheric bars of pressure needed to extract espresso. The pressure builds up by drawing tap water from a reservoir and pumping it through a heat exchanger prior to being pumped through the ground coffee in the group head.

Pumps tend to be less expensive than piston-driven machines, and tend to last longer, however both types of machines may become damaged due to excessive use and poor cleaning. Pumps are also more complicated mechanically, which can increase prices of even simpler models.

Some espresso machines make use of steam pressure instead of a pump in order to brew espresso. The drawback is that the same boiler that produces steam also increases the temperature of the water until it reaches boiling, which can lead to over-extraction. The machines also need to continually rebuild their pressure between cups. This takes energy and time.

Many espresso machines utilize the rotary or vibration pump, with a vibrating model using a rotating disc that generates the pressure and an rotary model that pushes hot water through the grounds at high speed. Both types of machines are capable of producing excellent espresso, but rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the component that heats water to an ideal temperature for extraction. The steam that is produced reaches the portafilter that contains ground espresso beans and is then funneled down into the cup. The steam causes enough pressure to push the coffee grounds through. This creates a foam on the top of the espresso. This is one of the hallmarks of a good espresso.

There are three kinds of espresso machines, each having distinct pumps and brew temperature. There are many ways to control the amount of brew, as well as the size of the cup that can be produced by the machine.

The first espresso machines espresso machines were steam types. They employed one boiler to create steam and brew, however the pressure they were able to produce was very low - just two bars of atmospheric pressure maximum. The coffee tasted bitter and burnt. The modern espresso machine was designed by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most commonly used espresso machine is a semiautomatic with an electric pump. These are what people imagine when they think of an espresso machine. Semi-automatic machines require you to grind and tamp the beans by yourself however the pump controls the water flow and pressure. This is a fantastic combination of human control and mechanized accuracy.

The Filter

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

A filter can also help with flavor because it allows for a longer flowering period. This lets the beans release their flavors, and improves extraction.

However it is crucial to keep in mind that even a good filter can produce a bad cup of coffee, because the quality of the beans and extraction is still crucial.

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 put the portafilter, the device used to place the grounds of coffee into while making espresso.

In the steam-driven espresso machine hot water is heated in an airtight container to create steam, which is then pushed through the grounds under high pressure. They are less expensive and easier to maintain than pumps-driven models. However, they are limited in their capacity to create the perfect conditions for brewing, since 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 become more popular. They use an air-compressor to force hot water through the ground. They are also more mobile than steam-driven electric espresso machines.