9 Things Your Parents Teach You About Machine Espresso

How Does machine espresso (check out this one from www.coffeee.uk) Work?

Machine espresso uses precision pressure and amazing filter technology to make the delicious coffee we enjoy. How exactly does it work?

To make espresso hot water is forced under high pressure through finely ground coffee. The process is similar to making drip coffee, but the difference is in the pressure.

The Head of the Group

The group head is the portafilter that is inserted when you are making espresso. It is responsible for dispersing the water into the portafilter before controlling the pressure of the extraction. There are a variety of group heads each with distinct advantages and drawbacks. Some are focused on temperature stability, some on pre-infusion features, and others are designed to control the lever. Some have a combination, such as the E61. This is a popular choice among baristas since it provides multiple advantages in a single package.

As you can see in the above photo The group head features numerous notches that you can place your portafilter and then twist it manually to secure it. There is also a gasket made from rubber which is located inside the notches to help create an airtight seal after inserting your portafilter into the machine. The notches permit precise placement of your portafilter. This is crucial to ensure an efficient extraction.

Aside from allowing you to easily insert your portafilter, the group head is also responsible for maintaining an even temperature. This is achieved by cycling hot water around the portafilter, and through the brew-basket, making sure that the temperature is at the right level to extract the coffee. This is vital, because just a few degrees could make the difference between excellent and great espresso.

The Pump

The motorized pumps in rotary espresso machines provide the nine atmospheric bars of pressure required for espresso extraction. This differs from manual piston machines that rely on a lever. This pressure is built up by pumping water through a heat exchanger and then through the ground coffee.

Pumps tend to be less expensive than piston-driven machines and tend to last longer. However, both types of machines may be damaged by excessive use and inadequate cleaning. Pumps are also more complicated mechanically, which could increase the price of even the simpler models.

Some espresso machines can eliminate the pump completely and use steam pressure to brew espresso. This can result in over-extraction because the boiler that makes steam also warms the water to boil. In addition these machines are often required to rebuild their pressure between cups, which takes time and energy.

A majority of espresso machines use the rotary or vibration pump, with a vibrating model that uses a vibrating disc to generate the pressure, and an rotary model that pushes hot water through the grounds under high speed. Both machines produce great espresso, however rotary machines are more quiet, durable and less likely to break.

The Boiler

The boiler is the component which heats the water to the optimal temperature to extract. The steam that is created is then directed to the portafilter, which contains the espresso coffee grounds. It is then pumped into the cup. The steam causes pressure to push through the coffee grounds. This produces a layer of crema on top. This is one of the hallmarks of a great italian espresso machines.

There are three kinds of espresso makers. They differ in the kind of pump they use and how hot the brew is. There are many ways to control the strength of the brew and the size of the cup that can be produced by the machine.

The first espresso machines were steam-type. They had one boiler to create both steam and brew but the pressure they could generate was low - only two bars of atmospheric pressure maximum. The coffee tasted bitter and burned. The modern espresso machine was created by the Milanese producers Luigi Bezzerra & Desiderio Pavoni.

The most common espresso maker is a semiautomatic machine that has an electric pump. When people think of espresso machines, they imagine these machines. If you have a semi-automatic machine you grind the beans and then tamp them by hand, but the pump controls the flow of water and pressure. This is a great compromise between the human touch and the mechanised accuracy.

The Filter

Espresso machines usually use a filter that separates the grounds of the coffee from the hot water. The filter is also a vital component of the machine's temperature control, as it prevents overheating.

A filter also helps with flavor as it allows for an extended flowering time. This helps the beans to release their nuances and gives an opportunity for a better extraction.

It is important to remember that even the best filter could result in a poor cup of coffee. The quality of the beans, and the extraction process remain crucial.

It's here that the magic happens. 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 coffee grounds in, when making espresso.

Steam-driven espresso machines make use of hot water that is heated inside an airtight container to produce steam. The steam then pushes hot water through the grounds of the coffee under pressure. These types of machines are typically less expensive and easier to maintain than pumps-driven models. However, they are not as efficient in their ability to provide the perfect brewing conditions since they operate at 1-1.5 bars of pressure. The perfect shot requires 9-10 bar.

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