The Most Hilarious Complaints We ve Received About Machine Espresso

How Does Machine Espresso Work?

The machine espresso uses precise pressure, as well as a filtering technology that is amazing to make the coffee you love. But how exactly does it work?

Espresso is created by forcing hot water under pressure through finely ground coffee. The process is similar to making drip coffee. However, the pressure is the main difference.

The Group Head

The name implies, the group head is where you place your portafilter when making espresso. It is responsible for dispersing water into the portafilter and then controlling the pressure that results from the extraction. There are many different kinds of group head, each with their unique advantages and drawbacks. Some are designed to provide temperature stability while others are designed to handle pre-infusion. Some are designed to control the lever. There are some that include a mix of features, like the E61 one, which is to be the most popular among baristas for its ability to provide multiple benefits in a single package.

As you can see from the picture above the head of the group is fitted with a variety of notches. You can place your portafilter into these notches and turn the head around to secure it. A gasket made of rubber is positioned inside the notches to help make a seal when you insert your portafilter. The notches on the head permit a precise location of the portafilter which is necessary to ensure a consistent extraction.

Aside from allowing you to easily place your portafilter in, the group head is responsible for maintaining a consistent temperature. It does this by circulating hot water through the brew basket, and around the portafilter to ensure that it is always at the correct temperature to extract. It is important to realize that even a few degree deviation can make the difference between a good and a excellent espresso.

The Pump

Motorized pumps in rotary espresso machines provide the nine atmospheric bar pressure required for espresso extraction. This differs from manual piston machines that rely on levers. The pressure is created by drawing tap water from a reservoir, and pumping it through a heat exchanger prior to it is shot through the ground coffee inside the group head.

Pumps are generally cheaper and last longer than piston-driven machines. However, both types of machines are susceptible to degrading due to excessive use and poor cleaning. Pumps are also more complex mechanically, which can increase the cost of even simplest models.

Certain espresso machines eliminate the pump completely and instead utilize steam pressure to make espresso. The downside is that the same boiler that produces steam also increases the temperature of water to boiling which could lead to excessive extraction. The machines must also constantly rebuild their pressure in between cups. This takes energy and time.

A large majority of espresso machines employ either a vibration or rotary pump. A vibration model utilizes an oscillating disk to create pressure, while a rotating model pushes hot water through the ground at a rapid speed. Both types of machine are capable of producing excellent espresso, but the rotary models are quieter and more durable than vibration pumps.

The Boiler

The boiler is the one that is used to heat the water to a temperature that is ideal for extraction. The steam created reaches the portafilter, which is a container for espresso grounds. It is then pumped into the cup. In this process, the steam creates pressure that pushes through the coffee grounds. This creates a crema on the top of the espresso. This is one of the hallmarks of a good espresso.

There are three types of espresso makers. They differ in the type of pump they use and the degree of heat that the coffee is. There are a variety of ways in which the brew can be controlled and the dimensions of the cup the maker can create.

The earliest espresso machines were steam-based. They employed only one boiler to make steam and brew, but the pressure they could create was minimal - two bars of atmospheric pressure at the most. The coffee tasted bitter and burnt. This is the reason why Milanese manufacturers Luigi Bezzerra and Desiderio Pavoni invented the modern espresso machine.

The most popular Espresso Machines Home machine is a semiautomatic model with an electric pump. When people think of espresso machines, they picture these machines. Semi-automatic machines require you to grind and tamp the beans yourself however the pump controls the flow of water and pressure. This is a great combination of human control and mechanised consistency.

The Filter

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

A filter also helps with flavor, as it permits a longer flowering phase. This allows the beans to let their nuances out and provides an opportunity to improve extraction.

It is important to remember that even the most efficient filter can result in a bad cup of coffee. The quality of the beans, and the extraction, are still very important.

This is where the magic happens, it's the thing that makes espresso taste great. The grouphead, also referred to as the brewhead, is where the portafilter (the device you put the coffee ground into) is located when you're making espresso.

Steam-driven espresso machines make use of hot water that is heated inside an airtight container to make steam. The steam then pushes hot water through grounds of coffee at high pressure. These types of machines are generally cheaper and easier to maintain than pump-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 force hot water through the grounds and are significantly more portable than steam-driven electric machines.