Coffee Machines: What Are the Different Parts and Their Uses

Intelligent software, stainless steel boilers, and copper tubes: pieces of equipment precision-engineered to make a coffee machine. 

Ultimately, the inside of a coffee machine is a maze of steam, wires, and metal. However, underneath all the chrome, copper, and wiring, a coffee machine only pumps hot water through ground coffee.

Below is a list of different coffee machine parts and how they work together to provide you with a delicious cup of Joe. 

List of Different Coffee Machine Parts

The Tamper

A tamper is a piece of equipment that compacts espresso grounds into an espresso machine’s basket.

A tamper’s job is to pack the grounds for a good shot equally. The basket size and portafilter you are tamping must match the tamper size. 

Lastly, your tamper should be constructed of lightweight metal. Therefore, it would be best to avoid wooden tampers to ensure no breakage. 

The Portafilter

A metal filter basket mounted inside a handle is known as a portafilter, also referred to as a portable filter. 

The portafilter is inserted and secured into the coffee maker after being filled with finely ground coffee and tamped.

A portafilter comes in many different sizes. However, the two most commonly used portafilters are 58mm and 53 mm. 

Both sizes can make a great cup of java. However, 58mm is the most typical size for commercial machines. 

When equipped with the appropriate baskets, 58mm and 53m use the same quantity of ground coffee. 

But a smaller tamper won’t be able to equally compress all of the coffee, even though it can fit in a 58mm basket. So, ensure that you choose your tamper size accordingly. 

The Saturated Group Head

This group head is accessible to the boiler in a saturated group head. As a result, the group head is filled with hot water and functions as a boiler extension. 

A saturated group head will reach the proper temperature with the water in the boiler much more quickly than waiting for the pieces of brass to heat up.

The Semi-Saturated Group Head

Coffee machines such as Profitec Pro 300 or the LUCCA A53 come with a semi-saturated group head that performs the same job as the saturated group head. 

The main difference between the two is that the area right above the dispersion block is isolated from the boiler instead of having the entire group head exposed to it.

The enlarged boiler’s gicleur line enters the dry space above the dispersion block. From there, it travels through a three-way valve coupled to a third “waste” line and the dispersion block.

The E61 Group Head

The E61 Group head, which La Faema first developed in 1961, is a traditional element of a coffee machine. This style of group head can be found on different types of coffee machines.

This type of group head has a few unique characteristics. The entire group head is made of brass and is heavily constructed, weighing a little over 9 pounds.  

Although it takes the entire group around fifteen minutes to reach temperature, once it does, it will stay at that temperature with ease. 

Additionally, getting into an E61 group head to do routine repairs and maintenance is not too difficult. In fact, it’s rather easy for people who know their way around a tool kit. 

But, one thing to remember is that this type of group head requires more involvement from the barista. 

You will have complete control over the volume and length of the shot rather than being able to let the machine do all the work for you. 

The E61 group head is a mechanically-controlled component with three valves. One of these valves allows water from the boiler to enter the group head.

The second valve lets water into the portafilter. The third valve is there to release any back pressure caused by the portafilter. 

As far as functionality is concerned, the water intake, a sizable orifice on the back of the group head, receives water from the boiler. 

Then, water travels up to the top chamber, known as the filter chamber, from the outer chamber at the top of the group head. 

From there, the water enters the brewing channel through the water intake nozzle. The brew valve closes the top chamber when the brew lever is depressed. 

Water flows from the brew channel into the area around the water inlet cam as soon as the brew lever is halfway up.

Next, the water travels in two directions: through the infusion passages and the dispersion screen. It also flows into the infusion chamber after passing the open pre-infusion chamber. 

However, at this moment, that pump doesn’t turn on. Instead, the moderate pressure created by the heat causes the water to travel through the system.

Typically, the term pre-infusion is used to describe this period of moderate pressure. 

Pre-infusion allows the bed of coffee in the portafilter basket to stabilize with hot water for a long time before applying the high pressure of brewing. 

This will compensate for any discrepancies in dosing, dispersing, and tamping while lowering the likelihood of channeling. 

The E61’s mechanical lever allows the operator to regulate the pre-infusion duration.

The pump starts to work when the brew lever is fully raised, and pressured water starts to flow through the coffee machine. 

The water input cam will finish raising the brew valve at this point, sealing the pre-infusion valve in the process. 

The extremely pressurized, hot water is only permitted to exit through the dispersion block and onto the ground coffee when the pre-infusion valve is closed.

The Single Boiler

Two thermostats and one heating element make up the boiler. An appropriate temperature range for brewing coffee is set on one thermostat. 

The other is set to a temperature that will cause steam and water to boil.

Water can be heated either to the boiling point or brewing temperature, but not both at once.

Consequently, you cannot steam milk and pull shots with a single boiler machine. When switching from espresso to steaming and vice versa, you must wait for the water to reach the proper temperature.

Vibratory Pump

The vibratory is a miniature electromagnetic device found inside coffee machines. It has a coil of metal that contains a piston. 

The magnet quickly moves the piston front and back when an electrical current flows through the coil, pushing water through the coffee maker.

These pumps are more compact, less expensive, and typically simpler to replace.

The Rotary Pump

A rotary pump is a mechanical pump. It works by offsetting a disc inside a sizable, rotary spherical chamber. 

The veins in the section contract as the disc rotates by pressing against the outer chamber wall. This causes pressure to build up. 

When the portion expands, water is sucked in, and when the segment contracts, water is pushed out. 

Compared to other pumps, rotary pumps are quieter, provide more consistent pressure, and typically have longer lifespans.


The Proportional-integral-derivative controller or PID is a straightforward computer that regulates the heating element to maintain the desired temperature of the water. 

To do this, a temperature probe within the boiler and the heating element are both connected to a PID. 

The PID constantly reads the temperature probe’s input and, using a preprogrammed algorithm, cycles the heating element on and off.

The Heat Exchanger

As mentioned before, a single boiler coffee maker can only heat water to one temperature. However, you need boiling and non-boiling water for the brewing process.

This means that in order to pull a shot, you must first heat the brewing water, then wait for it to reach the boiling point before adding steam. 

Next, you will have to wait again for fresh water to get up to brewing temperature, especially if you want to pull multiple shots from a single boiler coffee machine.

The heat exchanger is the answer to this issue. Although a second water line extends from the pump, it does not feed directly into the boiler. Instead, it travels within a copper tube through the boiler’s body.

The brew water in the heat exchanger is heated but not fully boiled. It doesn’t touch the boiling water section. 

The outcome is water that is at two different temperatures, enabling you to steam milk and draw shots at the same time.

Unfortunately, using a heat exchanger makes it more difficult to regulate the temperature of the brewing water. The brewing water may become excessively hot if left in the exchange coil for too long. 

This is why temperature surfing bleeding or purging a small amount of water is crucial before brewing espresso with a heat exchanger.

However, the solution to this dilemma is the dual boiler. It can be used in equipment designed to produce large quantities of drinks with simultaneous steaming and brewing.

The Dual Boiler

Dual boiler machines, as the name suggests, feature two distinct boilers. Both receive water from the pump.

One boils water, which is necessary to steam milk. The other raises the water’s temperature to the brewing level.

Typically, dual boiler machines have a digital temperature controller or PID, which precisely regulates the temperatures of both boilers.

Steam Wand

A steam wand is a component of a coffee machine that is used to heat and froth milk. Depending on the style of your coffee machine, the lever on this steam wand can be used to control its operation. 

Typically, the steam wand is like an elongated pipe made of chrome. 

The Group Dispense Switch

Although the group dispense switch is only an On/OFF switch, it functions similarly to the dosing keypads. It stands above the groups. 

A dispense button is found on some automatic coffee machines, providing various other operational features and options.

The Group Dosing Keypad

Both automated and super-automatic espresso machines include group dosing keypads. It houses buttons that let you power up the group head once pushed. 

The Pressure Gauge

The pressure gauge is located on the front of a coffee maker. It houses two needles or “hands” that display the pump operating and boiler pressure. 

The pressure gauge allows you to track your coffee machine’s health, temperature, and pressure. 

Wrapping Up

The equipment you use to make a fresh cup of java is integral to your everyday life. Therefore, it’s crucial to understand how such equipment works and how to use it properly. 

So, if you don’t know what goes on in a coffee machine, this article shares everything you need to know about the important parts of a coffee machine. 

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