9 Things 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 make the perfect cup of coffee. How exactly does it work?

To make an espresso, hot water is pushed under pressure through finely ground coffee. The process is similar to making drip coffee. However, the pressure is the major difference.

The Group Head

The name implies, the group head is the place you insert your portafilter when making espresso. It is responsible for dispersing the water into the portafilter and then controlling the pressure of the extraction. There are a variety of group heads each with their own advantages and disadvantages. Some are designed to provide stability of temperature while others are built to handle pre-infusion. Others are made to control the lever. There are some that have a combination of features, such as the E61 one, which is the most popular choice among baristas due to its capacity to offer multiple perks in one package.

As you can see in the image above The group head features several notches to put your portafilter, then twist it manually to lock it in. A rubber gasket is located inside the notches, which helps create a seal when you insert your portafilter. The notches on the head allow for an exact location of the portafilter which is crucial to ensure an even extraction.

Aside from allowing you to easily connect your portafilter, the group head is responsible to maintain an even 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 crucial, since just a few degrees could make the difference between a good and excellent espresso.

The Pump

The motorized pumps that are used in espresso machines that rotate provide the nine atmospheric bar pressure that is required to extract compact espresso machine. This is different from manual piston machines that use levers. The pressure builds by drawing tap water from a reservoir and pumping it through a heat exchanger before it is shot through the ground coffee inside the group head.

Pumps are generally less expensive and last for longer than piston-driven machines. However, both types of machines may degrade due to excessive use and insufficient cleaning. Pumps are also more complex mechanically, which can raise prices of even simple models.

Some espresso machines do away with the pump entirely and utilize steam pressure to make best espresso machine under 500. This could lead to over-extraction since the boiler that makes steam also warms the water to boil. The machines must also constantly rebuild their pressure in between cups. This requires energy and time.

Many espresso machines use an rotary or a vibration pump. A vibration model uses a vibrating disk to generate pressure, whereas a rotating model pushes hot water through the ground at a high speed. Both models are capable of producing excellent espresso, however Rotary machines are quieter and more durable than vibration pumps.

The Boiler

The boiler is the component that heats water to the optimal temperature for extraction. The resultant steam then reaches the portafilter which holds the ground espresso coffee, and gets funnelled down into the cup. During this process, the steam causes pressure to push through the coffee grounds. This results in a whipped-up top of the espresso. This is one of the main characteristics of a great espresso.

There are three types of espresso makers, which differ in the kind of pump they use and the degree of heat that the brew is. There are various ways that the brew may be controlled and the dimensions of the cup the maker can create.

The first espresso machines were steam-type. They used only one boiler to make both steam and brew however the pressure they were able to create was minimal - two bars of atmospheric pressure maximum. This led to the coffee tasting burnt and bitter. The modern espresso machine was designed by the Milanese makers Luigi Bezzerra & Desiderio Pavoni.

The most popular espresso machine is a semiautomatic that has an electric pump. These are what people imagine when they think of an espresso maker. With a semi-automatic machine, you grind the beans and tamp them by hand. The pump provides regulated water flow and pressure. This is an excellent solution that combines human control with mechanised accuracy.

The Filter

Espresso machines usually have a filter that separates the coffee grounds from the hot water. The filter is also an important component of the temperature control system, as it keeps the machine from overheating.

It also helps with flavor as a filter lets you enjoy a longer bloom time. This helps the beans release their flavor and gives an opportunity for better extraction.

It is important to keep in mind that even the best cheap espresso machine filter can result in a bad cup of coffee for espresso machine. The quality of the beans, and the extraction process, remain crucial.

This is where the magic happens, it's what makes espresso taste great. The grouphead, sometimes called the brew head, is the place where the portafilter (the device you put the ground coffee into) is located when you're making espresso.

In an best home espresso machine machine that is driven by steam, hot water is heated in an airtight container to create steam. This then pushes the hot water through the grounds with high pressure. These kinds of machines are usually cheaper and easier to maintain than pump-driven models. However, they are not as efficient in their ability to create the perfect conditions for brewing, because they operate at 1-1.5 bars of pressure, while the perfect shot requires 9-10 bars.

In recent times, espresso machines powered by compressed air-pump have become increasingly popular. They utilize an air compressor to force hot water through the grounds, and are far more portable than steam-driven electric machines.