10 Things That Your Family Teach You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso uses precision pressure and amazing filter technology to make the perfect cup of coffee. What exactly is it?

To make an espresso 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 major difference.

The Head of the Group

As the name suggests, the group head is the place you place your portafilter while brewing espresso. It disperses the water into the portafilter and regulates the pressure during the extraction. There are various kinds of group head, each with their particular advantages and disadvantages. Some focus on temperature stability, while others on pre-infusion capabilities, while others are designed to control the lever. Some are a combination, such as the E61. This is a preferred choice for baristas as it provides a variety of benefits in one package.

As you can see in the above image the group head comes with numerous notches that you can place your portafilter before twisting it with your hands to lock it in. There is also a gasket made from rubber which is located inside the notches and helps to create the seal when you insert your portafilter into the machine. The notches allow for precise placement of your portafilter. This is crucial for an efficient extraction.

The group head does not just allow the portafilter to be inserted easily however, it also keeps an even temperature. It does this by cycling hot water through the brew basket, and around the portafilter, ensuring that it's always at the right temperature for extraction. It is important to remember that even a few degree variation can mean the difference between a great and a 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 required for espresso extraction. The pressure is created by pumping water through a heat-exchanger and then through the ground coffee.

Pumps tend to be cheaper than piston-driven machines, and espresso Machines for home tend to last longer, but both types of machines can degrade with overuse and insufficient cleaning. Pumps are also more complex mechanically, which could increase the cost of even the simpler models.

Certain espresso machines utilize steam pressure instead of a pump to brew espresso. This can result in over-extraction because the boiler that produces steam also warms the water to boil. They also have to constantly rebuild their pressure in between cups. This requires energy and time.

A large majority of espresso machines employ the rotary or vibration pump. A vibration model employs an oscillating disk to create pressure, whereas the Rotary model pushes hot coffee through the ground at a fast speed. Both machines can make excellent espresso, but rotary machines are more stable, quieter and less likely to break.

The dual boiler espresso machine

The boiler is the part that heats water to the ideal temperature for extraction. The resulting steam reaches the portafilter which holds the ground espresso and gets funnelled down into the cup. During this process, the steam creates pressure that pushes through the grounds of the coffee. This results in a crema on the top of the espresso coffee machine. This is a hallmark of a good espresso.

There are three kinds of small espresso machine makers, which differ in the kind of pump they use and how hot the brew is. There are different ways to control the amount of brew, as well as the size of the cup that can be made by the machine.

The first espresso machines were steam type. They used a single boiler to make both steam and brew, but the pressure they could generate was low - only two bars of atmospheric pressure at the most. The coffee tasted bitter and burnt. The modern espresso machine was created by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.

The most popular espresso maker is a semi-automatic machine that has an electric pump. When people think of espresso machines, they think of these machines. Semi-automatic espresso machine machines require you to grind and tamp the beans yourself however the pump controls the flow of water and pressure. This is a great compromise between the human touch and the mechanized quality.

The Filter

Typically, espresso machines use a filter to separate out the grounds of coffee as they move through the hot water. The filter is also an important element of the temperature control system because it stops the machine from overheating.

Filters also aid in flavor because it allows for an extended flowering time. This helps the beans to release their nuances and gives an opportunity to improve extraction.

It is important to keep in mind that even the most efficient filter can make a bad cup of coffee. The quality of the beans and the extraction process remain crucial.

It's in this area that the magic takes place. This is what makes espresso taste so delicious. The grouphead, also referred to as the brewhead, is where the portafilter (the device you put the coffee grounds into) sits when you're making espresso.

In a steam-driven espresso machine hot water is heated in an airtight container to produce 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 not as efficient in their ability to produce the perfect brewing conditions because they operate at 1-1.5 bars of pressure. While the perfect shot requires 9-10 bar.

In recent years, compressed air-driven espresso machines have been gaining popularity. They use an air compressor to force hot water through the ground and are more mobile than steam-driven electric espresso machines.