9 Things Your Parents Teach You About Machine Espresso

How Does Machine Espresso Work?

Machine espresso makes use of precise pressure and incredible filter technology to produce the delicious coffee we enjoy. What exactly is it that makes it work?

Espresso is made by pushing hot water under 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 disperses water into the portafilter, and regulates the pressure of extraction. There are many different types of group heads each with its own advantages and disadvantages. Some are specifically designed for temperature stability while others are specifically designed to handle pre-infusion. Others are made to control the lever. There are also some that have a combination of features, like the E61 one, which is the classic choice among many baristas due to its capacity to offer multiple perks in one package.

As you can see from the above photo, the group head is fitted with several notches. You can place your portafilter in these notches, then twist the head to lock it. A gasket made of rubber is positioned inside the notches to help create a seal when you insert your portafilter. The notches allow for precise placement of your portafilter. This is crucial to ensure an even extraction.

The group head does not just allow you to insert your portafilter easily however it also keeps an even temperature. It does this by cycling hot water through the brew container and around the portafilter, ensuring that it is always at the correct temperature for extraction. It is crucial to keep in mind that even a small variation can mean the difference between a great and a excellent espresso.

The Pump

In contrast to manual piston machines which use 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. The pressure is built by pumping water through a heat-exchanger and then through the ground coffee.

Pumps are generally cheaper and last longer than piston-driven machines. However, both kinds of machines can deteriorate due to overuse and poor cleaning. They also increase the complexity of mechanical systems, which can result in a high price tag on even the most basic models.

Some Breville Café Roma Espresso Machine - Stainless Steel machines do away with the pump completely and instead make use of steam pressure to make espresso. The downside is that the same boiler that produces steam also increases the temperature of water to boiling which can cause over-extraction. These machines also have to continuously rebuild their pressure between cups. This requires energy and time.

Many espresso machines employ a vibration or rotary pump, which has a vibration model using a rotating disc to create pressure, and the rotary model pushing hot water through the grounds under high speed. Both machines can make great espresso however rotary machines tend to be more quiet, durable and less likely to fail.

The Boiler

The boiler is the part that heats water to an optimal temperature to extract. The steam that is created reaches the portafilter, which is a container for espresso grounds. It is then poured into the cup. In this process, the steam creates pressure that pushes through the coffee grounds. This creates a foam on the top of the espresso. This is the hallmark of a good espresso.

There are three kinds of Swan Espresso Machine And Milk Frother - Nordic Grey machines, each with a different type of pump and brew temperature. There are a variety of ways in which the brew can be controlled and the dimensions of the cup the machine can produce.

The earliest espresso machines were steam type. They used a single boiler to make both steam and brew, however, the pressure they could create was minimal - two bars of atmospheric pressure at the most. The coffee tasted bitter and burned. The modern espresso machine was created by the Milanese manufacturers Luigi Bezzerra & Desiderio Pavoni.

The most common espresso maker is a semi-automatic one with an electric pump. This is what people envision when they think of an espresso machine. Semi-automatic machines require you to grind and tamp the beans yourself The pump, however, regulates the flow of water and pressure. This is a great solution that combines human control with mechanized consistency.

The Filter

Typically, espresso machines have filters that separate the grounds of coffee when they pass through the hot water. The filter is also an essential element 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 phase. This allows the beans to release their nuances and gives an opportunity for better extraction.

It is important to remember that even the finest filter can result in a bad cup of coffee. The quality of the beans, and the extraction, remain crucial.

It's in this area that the magic takes place. This is the reason why espresso tastes so delicious. The grouphead (also called the brewhead) is where you place the portafilter - the thingy that you use to put the grounds of coffee into when making espresso.

In a 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 generally less expensive and simpler to maintain than pumps-driven models. They are however limited in their ability for creating the ideal conditions for brewing since they only operate with 1-1.5 bar of pressure. The ideal shot requires 9-10 bars.

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