How To Explain Machine Espresso To Your Grandparents

How Does Machine Espresso Work?

The machine espresso is made using precision pressure, and filtering technology that is amazing to create the coffee you enjoy. How exactly does it work?

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

The Group Head

The group head is the portafilter you place in the espresso maker when making it. It disperses water into the portafilter, and regulates the pressure of extraction. There are several different types of group heads, each with their distinct advantages and disadvantages. Some are designed for stability of temperature while others are specifically designed to handle pre-infusion. Others are built 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 above photo the group head is fitted with a variety of notches. It is possible to place your portafilter into these notches and twist the head to secure it. There is also a rubber gasket in the notches and helps to create a seal when you insert your portafilter into the machine. The notches on the head permit a precise position of the portafilter which is essential for an even extraction.

Apart from allowing you easily connect your portafilter, the group head is also responsible for maintaining a consistent temperature. It does this by circulating hot water through the brew basket, and around the portafilter, making sure that it is always at the right temperature to extract. This is vital, because just a few degrees could mean the difference between good and excellent espresso.

The Pump

The motorized pumps in rotary espresso machines supply the nine atmospheric bar pressure required to extract best budget espresso machine. This is different from manually operated piston machines that employ levers. The pressure is created by removing tap water from a reservoir, and pumping it through a heat exchanger prior to being shot through the ground coffee inside the group head.

Pumps tend to be less expensive than piston-driven models, and they tend to last longer, although both types of machine can become damaged due to excessive use and poor cleaning. They also make mechanically complex that can lead to costly prices for even the most basic models.

Some espresso machines eliminate the pump completely and instead employ steam pressure to create espresso. This can cause over-extraction because the boiler that makes steam also warms the water to boil. The machines must also constantly rebuild their pressure between cups. This requires energy and time.

Many espresso machines employ the rotary or vibration pump, with a vibrating model using a vibrating disc to create the pressure, and a rotary model pushing hot water through the grounds at high speed. Both types of machine can make excellent espresso, however the rotary models are quieter and more durable than vibration pumps.

The Boiler

The boiler is the one that heats the water to the ideal temperature for extraction. The resulting steam reaches the portafilter that contains the ground espresso and is then funneled down into the cup. The steam generates enough pressure to push the grounds of the coffee through. This results in a layer crema on top. This is one of the hallmarks of a good discount espresso machines.

There are three types of espresso makers, and they differ in the type of pump they employ and the degree of heat that the coffee is. There are also different ways in which the brew can be controlled and the dimensions of the cup the machine is capable of making.

The first espresso machines were steam-type. They utilized one boiler to make both steam and brew however, the pressure they could produce was very low - just two bars of atmospheric pressure, at most. The coffee tasted bitter and burned. This is why Milanese makers Luigi Bezzerra and Desiderio Pavoni created the modern espresso machine.

The most popular espresso maker is a semiautomatic machine that has an electric pump. This is what people envision when they think of an espresso maker. Semi-automatic machines require you to grind and tamp the beans by yourself while the pump controls the flow of water and pressure. This is an excellent compromise between human touch and the mechanised consistency.

The Filter

Espresso machines usually have a filter that separates the grounds of coffee from hot water. The filter is also a vital part of the temperature control system because it stops the machine from overheating.

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

It is important to keep in mind that even the most efficient filter could result in a poor cup of coffee. The quality of the beans and the extraction process remain vital.

It's in this area that the magic happens. This is the reason why espresso tastes so good. The grouphead (also called the brewhead) is where you place the portafilter, the thingy which you put the coffee grounds in, when making espresso.

Steam-driven espresso machines make use of hot water heated in an airtight vessel to create steam. The steam then pushes hot water through grounds of the coffee under pressure. They are less expensive and easier for the owner to maintain than pumps-driven models. However, they are limited in their ability to create the perfect brewing conditions since they are only operating at 1-1.5 bars of pressure. However, the perfect shot requires 9-10 bars.

In recent years, espresso machines driven by compressed air-pump are becoming increasingly popular. They use an air compressor to force hot water into the grounds and are more portable than steam-driven electric machines.