How Does The Espresso Machine Work: Every espresso machine is based on the same concept of forcing hot water through ground coffee. These machines, which give us an exceptional variation of coffee we all know and love, are very complicated and simple at the same time. With so many tubes and stainless steel boilers, taking a look at the inside of an espresso machine can be overwhelming. But at the same time, the process of how espresso machines work is simple.
How Does The Espresso Machine Work
The water from a reservoir or a constant water supply goes into a boiler. A pump is connected between the reservoir and a boiler. It’s needed to push the water through the firm ground coffee located inside of a portafilter. A boiler is necessary to heat and hold the pressurized water that comes from a pump. From there, water gets sent into a group head before it gets turned into an espresso. And of course, espresso machines come with a steam wand which heats the milk.
To get a better understanding of how an espresso machine works, let’s take a look at its design as well as the process it takes to make a brilliant espresso.
The Water Supply
For an espresso machine to work, it needs a source of water. That source of water can be a reservoir located in the machine, or the machine could be connected to a constant water supply. There are espresso machines that offer both a reservoir and the ability to connect the espresso machine to a consistent source. There are advantages and disadvantages to both, but to understand how an espresso machine works, we need to know why each source is used.
An espresso machine with a reservoir is designed for the most high-quality espressos. The water is filtered and conditioned exactly for making espresso instead of coming from the tap.
An espresso machine with a consistent supply of water is usually found in coffee shops. You don’t have to worry about refilling the reservoir; Therefore, they are an excellent choice for cafes and restaurants.
A water pump is an essential part of an espresso machine. It pushes water through the ground coffee at about 120 psi.
When the espresso machine was invented, people needed to use manual labor, such as pistons, to create the necessary pressure. Today, we have two categories of pumps, the vibratory pump, and the rotary pump.
A vibratory pump works by rapidly moving the piston back and forth with the help of electricity. A piston is connected to a magnet surrounded by a metal coil; Electricity travels through that coil, causing rapid vibrations.
A rotary pump has a chamber with a disk and a motor inside. The motor spins the disk that is segmented into sections. As the disk spins, it pushes against individual segments, which in result creates pressure.
The espresso machine could not work without a boiler. It’s an essential part of an espresso machine. A boiler heats the water and holds the pressure created by the pump. Before we create an espresso, we must allow some time for a boiler to warm up the water.
The Group head and Portafilter
The group head is where the pressured and heated water reaches ground coffee and pulls a shot. Large espresso machines designed for cafes have more than one group head.
The group head is made of four basic parts:
- The portafilter is a metal basket set inside of a handle. Ground coffee is measured and put into the basket before the portafilter is locked in the espresso machine.
- A portafilter lock is a place where the portafilter gets set into the machine and locked.
- A pressure switch to activate the pump.
- A channel for the water to travel from the boiler to the portafilter.
The Steam Wand:
Espresso machines usually come with a steel tank designed to steam the milk. The espresso machine does not need the steam wand in order to work, but the steam wand is an essential part.
Most standard espresso machines come with a single boiler. Therefore, they need two thermostats. One thermostat is set for brewing coffee while the other one is set to boil water and produce steam.