The Ugly The Truth About Machine Espresso

How Does Machine Espresso Work?

Machine espresso employs precise pressure and mind-blowing filter technology to make the perfect cup of coffee. What exactly is it that makes it work?

In order to make professional espresso maker, hot water is pushed under pressure through finely ground coffee. The process is similar to making drip coffee however the main difference lies in the pressure.

The Group Head

The group head is the portafilter that you put in when making espresso. It is responsible for dispersing water into the portafilter and then controlling the pressure that results from the extraction. There are numerous kinds of group heads each with distinct advantages and drawbacks. Some are designed to provide temperature stability while others are designed to handle pre-infusion. Some are designed to control the lever. Some include a combination like the E61. This is a popular choice among baristas because it offers multiple benefits in one package.

As you can see in the photo above the group head comes with numerous notches that you can place your portafilter and then twist it manually to secure it. A gasket made of rubber is placed inside the notches, which helps create a seal as you insert your portafilter. The notches on the head permit an exact location of the portafilter which is vital to ensure a consistent extraction.

Apart from allowing you easily connect your portafilter, the group head is responsible to maintain an even temperature. It does this by cycling hot water through the brew basket, and around the portafilter, ensuring that it is always at the correct temperature for extraction. This is vital, because just a few degrees could be the difference between a good and great espresso.

The Pump

The motorized pumps in espresso machines rotary provide nine atmospheric bar pressure required to extract espresso machine black friday. This differs from manual piston machines that use a lever. The pressure is created by drawing tap water from a reservoir, and pumping it through a heat exchanger prior being pushed through the ground coffee in the group head.

Pumps tend to be cheaper than piston-driven models, and they tend to last longer, however both types of machines could get damaged through overuse and lack of cleaning. They also make mechanically complex, which can result in the cost of even the simplest models.

Certain espresso machines eliminate the pump completely and instead employ steam pressure to create espresso. This can lead to over-extraction as the boiler that makes steam also causes the water to boil. In addition these machines are often required to restore their pressure between cups, which requires time and energy.

A majority of espresso machines use the rotary or vibration pump, which has a vibration model using a rotating disc to create pressure and an rotary model that pushes hot water through the grounds at high speed. Both machines can make excellent compact espresso machine but rotary machines are more stable, quieter and less likely to fail.

The Boiler

The boiler is the component that heats the water to the optimal temperature to extract. The steam that is produced reaches the portafilter, which contains the ground espresso coffee and is then pumped into the cup. During this process the steam causes enough pressure to push the grounds of coffee through. This results in a crema on the top of the espresso. This is one of the main characteristics of a great espresso.

There are three types of espresso makers, and they differ in the type of pump they employ and the degree of heat that the brew is. There are different ways to control the brew and the size of cup that can be produced by the machine.

The first espresso machines were steam-types. They used one boiler to create both brew and steam, however, the pressure they could generate was low - only two bars of atmospheric pressure at most. This led to the coffee tasting burnt and bitter. This is the reason Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most common espresso machine is a semiautomatic with an electric pump. These are what people imagine when they think of an espresso maker. Semi-automatic machines require you to grind and tamp your beans yourself, but the pump regulates the flow of water and pressure. This is an excellent compromise between human touch and mechanized consistency.

The Filter

Typically, espresso machines have a filter to separate out the coffee grounds as they pass through the hot water. The filter is also a vital part of the temperature control system as it prevents the machine from overheating.

It also helps with flavor, since a filter can allow for a longer bloom phase. This allows the beans to release their flavors, and improves extraction.

However it is crucial to keep in mind that even a good filter can make a terrible cup of coffee as the quality of the beans and extraction is still vital.

It's here that the magic takes place. This is the reason why espresso tastes so delicious. The grouphead, often called the brewhead, is where the portafilter (the thingy you put the ground coffee into) is located when you're 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 at high pressure. These kinds of machines are usually less expensive and simpler to maintain than pumps-driven models. However, they are not as efficient in their ability to create the perfect conditions for brewing, since they are only operating at 1-1.5 bars of pressure. The perfect shot requires 9-10 bars.

In recent years, compressed-air-pump-driven italian Espresso machine machines have been gaining popularity. They utilize an air compressor to force hot water through grounds and are significantly more portable than electric steam-driven machines.