Everything You Need to Know about How Do Espresso Machines Work

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Last updatedLast updated: May 20, 2021
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We’re all constantly looking for ways to get more done on our normal days. One of the ways to add a few extra minutes to your day is to avoid the long queues at the coffee shop and invest in a quality espresso machine. Having your own espresso machine enables you to make your café favorites whenever you want without leaving your home or your office to get them.

With coffee makers being all the rage right now, the question on everyone’s mind might be how do espresso machines work? In this article, we’ll be looking at the parts that make up automatic espresso machines. I’ll also be looking at the way manual coffee machines work, and I’ll give you a nifty guide on prolonging the life of your espresso machine by cleaning it properly.

Parts of automatic espresso machine

Everything You Need to Know about How Do Espresso Machines WorkTo fully understand how espresso machines work, it’s necessary to know what the parts are as well as what their functions are. While espresso machines aren’t made up of too many complex parts, each component plays an integral part in creating your favorite cup of coffee.


Everything You Need to Know about How Do Espresso Machines WorkTo create the perfect espresso drink you need water, coffee grounds and pressure. It takes roughly 9 bars of pressure to make the average coffee drink. The pressure created puts the water in direct contact with the coffee grounds. To do this, a pump is used. All espresso machines contain one of two types of pumps: vibratory or rotary pumps.

Vibratory pumps

These types of pumps use a spring and piston design that easily vibrates to move water around and create the pressure needed to make an espresso. Vibratory pumps are commonly used because they have quite a few benefits that make them ideal for compact home espresso machines.

Some of these benefits include:

  • Small pumps so they can easily fit into compact espresso machines.
  • They’re cheap enough to not inflate the cost of the machine.
  • Easily produce 9 bar pressure which covers the entry-level requirement for all espresso machines.
  • Can last up to 5 years in espresso machines that are used and maintained correctly.
  • They’re also easy enough to replace by yourself.

While these little pumps do make a bit of noise some brands make the effort of mounting these vibratory pumps in a way that makes them slightly quieter. If the sound of a noisy espresso machine is too much too handle first thing in the morning, it would be a good idea to look into these models.

Rotary pumps

Rotary pumps or vane pumps are larger motors that make use of a gear-type mechanism to generate pressure. These types of pumps are mechanical and are quite complex. Essentially, a motor spins a simple disc inside a larger chamber. The disc is then segmented into different sections by vanes and slats which control the rest of the machine.

The advantages of these pumps include the following:

  • They’re very quiet and don’t make the loud vibrating noise associated with vibratory pumps.
  • If the espresso machine is handled correctly, these pumps can last a lifetime and are considered to be the most reliable parts of a household espresso machine.
  • Unlike vibratory pumps, a rotary pump can operate with a reservoir or a direct water line.

If you want an espresso machine that has a rotary pump, the unit will be slightly larger than the compact versions and will also be more expensive. It is however worth investing in if you’re going to be using your espresso machine often.

Water reservoir

Everything You Need to Know about How Do Espresso Machines WorkA water reservoir, or water tank as it’s sometimes called, is the container that you find inside the espresso machine. The reservoir is covered with a lid to protect the water from dust or any other debris that could get into the water. It’s crucial to check the water levels inside the reservoir before using your espresso machine.

Smaller espresso machines often have a detachable reservoir which makes for easy cleaning. Some models also have clear water reservoirs making it easier to see the water levels.


Everything You Need to Know about How Do Espresso Machines WorkAside from how your espresso machine produces its water pressure, another crucial feature is the temperature at which the water is boiled. The way the water is boiled is called brew temperature and the method used distinguishes one model from another. The heating methods commonly used in espresso machines are listed below:

Boiler or heat shedding group

This is the original system used in traditional espresso machines. The water heats at a temperature ranging around 250°F or 120°C. The water temperature then drops to the correct brew range in the group just before hitting the coffee grounds. This is the way traditional spring lever espresso machines work.

While this is the tried and tested way of heating espressos, it’s not the most reliable way to do it. If the group is too low, you’ll end up with a final brew temperature that’s too low. When the group overheats, the brew temperature will be too hot. Using this type of boiler on your home espresso machine means you’ll have to turn the unit off after about five shots to cool down. If not, the temperature in the group will be too high.

Single boiler

Everything You Need to Know about How Do Espresso Machines WorkIn general, the more compact home espresso machines have a single boiler. Quite often there are two thermostats. One thermostat heats the water when brewing and the other thermostat heats the water when steaming. These boilers are popular choices because of their small sizes.

Average quality espresso machines are made using thermostats that can heat less than an ounce straight off the bat. High-end models use thermostats that can eat roughly 25 ounces of water. On average, you only need a thermostat that can boil anywhere from 12 to 16 ounces of water to have the right temperature espresso.

Double boiler

Everything You Need to Know about How Do Espresso Machines WorkThe major disadvantage of single boiler machines is that they can’t steam and pull shots simultaneously. Double boiler machines have one boiler used for seaming and another for brewing. Each boiler is set at a required temperature for the specific function the espresso machine needs to perform.

Theoretically, these types of boilers can produce the most stable temperatures to produce the perfect coffee drink. These two steam boilers can reach and maintain pressure ideal for frothing milk. This is ideal for drinks like lattes that require a great deal of milk foam.

A modern espresso machine that sports the double boiler feature is the Breville Fully Automatic Espresso Machine with Oracle Touch. With its 4-key formula, it offers caffeine lovers a variety of specialty coffee drinks. Not only is the temperature control unparalleled but the unit offers simultaneous steaming and extraction which offers a top-quality cup of espresso.

Other handy features that make this espresso machine a cut above the rest include its 8 customizable settings and programmable milk temperature. The user can also easily pre-program 5 favorite coffee drinks, making it that much quicker to make your favorite café specialty drinks.

The foam delivered by the steam wand is automatically textured to your set preference that not only increases the flavor but will have you making Barista-style coffee drinks in no time! It’s no wonder this espresso machine is listed as one of the most advanced automatic models on the market.

Heat exchanger

Bigger home machines or those used for commercial business use the heat exchanger system. Simply put, the heat exchanger is a pipe placed inside the actual boiler. As water pumps into the group, it flows through the pipe and heats up to within the brew range temperature.

Since heat exchanger heating systems use a single boiler, the boiler itself provides the steam needed for stretching milk. The heat exchanger assists in creating the desired temperature-regulated water needed for brewing the perfect espresso.

Group head

Everything You Need to Know about How Do Espresso Machines WorkA group head can be defined as the component of the espresso machine from which water is distributed into the coffee filter basket. Essentially it connects the unit to the group handle and in turn connects the water to the coffee grounds.

The two common types of group heads are saturated and semi-saturated. They can be defined as follows:

  • Saturated group heads: These groups’ heads are exposed to the boiler. They can easily reach the same temperature as the hot water because they’re simply an addition to the boiler and get flooded with the hot water.
  • Semi-saturated: These types of group heads are detached from the main boiler by a heat exchanger. Semi-saturated group heads are cheaper to manufacture and easier to fix if necessary. A down-side of these group heads is that they aren’t as stable in maintaining the desired temperature.


Everything You Need to Know about How Do Espresso Machines WorkThe portafilter is the part of the espresso machine that embraces the ground coffee or espresso beans before, during and after the brewing process. Portafilters create the required pressure to brew a palatable cup of espresso.

Just like the other components on an espresso machine, there are different options to use in different units. Four types of portafilters are listed as follows:

  • Commercial: The commercial portafilter can be used in both home espresso makers as well as commercial machines. Since these portafilters weigh more they’re able to produce better heat retention and are generally more stable. Expert coffee makers agree that these portafilters produce better pulls than the pressurized options. This makes it the best option for commercial espresso machines.
  • Adapters: Portafilter adapters enable the user to make small modifications allowing it to do more than what it was intended for. Generally, coffee lovers will use adapters to convert their existing portafilters to units that can sustain espresso or coffee pods.
  • Pods: Generally, pod portafilters are designed specifically for espresso pods. Pods are prepackaged little containers that contain the ground or tamped coffee. The user can easily insert or remove the capsule without too much effort.
  • Pressurized: A pressurized portafilter adds pressure immediately after the coffee extraction through a basket that features a two-layer bottom.

Without a doubt, one of the most popular espresso machines making use of a pressurized portafilter is the Gaggia Carezza De Luxe Espresso Machine. Since the portafilter is pressurized, it allows for both ground coffee beans and ESE pods to be easily brewed.

A pre-infusion feature pre-wets the coffee grounds before the brewing process starts, allowing not only for even extraction but for that robust flavor espresso lovers enjoy so much. Since the water reservoir is front-loaded, it can easily be pulled out and refilled when necessary.

It also sports a Pannarello frothing wand which is perfect for creating the right amount of foam needed to make delicious cappuccinos and lattes. The wand can be used to dispense hot water making it ideally suited to make tea and Americanos.

Steam wand

Everything You Need to Know about How Do Espresso Machines WorkModern espresso or coffee machines have a steam wand that usually hangs off to one side. This useful arm essentially forces steam into the milk. This steam slowly warms the milk with a small amount of pressure.

By doing this, air is introduced into the milk which causes the foam you see on drinks like lattes. The steam wand essentially works by shooting jets of steam through the small holes on the wand’s tip.

Control panel

Everything You Need to Know about How Do Espresso Machines WorkEssentially, the control panel on a coffee or espresso machine is the control center giving the user access to the unit’s different functions. Depending on the type of espresso machine, the functions could be controlled digitally or with switches and knobs. The models with switches could vary from rocker types to push-buttons. Pressure-sensitive switches are also an option on certain models.

Some of the functions and controls that you’d find on a control panel include the following:

  • Power – on/off
  • Brew control or temperature (in more upmarket models)
  • Steam control
  • Hot water dispensing

Drip tray

Everything You Need to Know about How Do Espresso Machines WorkAll espresso machines also have a drip tray. The drip tray is designed to catch any fluid spills. That avoids a mess on your countertop as well as on your machine. A drip tray is situated at the bottom of the espresso machine and usually has a grating over it. Some drip trays are detachable so that taller mugs can fit under the spouts. This is ideal for taller latte glasses.

How do manual espresso machines work

Everything You Need to Know about How Do Espresso Machines WorkManual espresso machines are regarded as one of the most hands-on ways of making espressos. Often called lever espresso machines, the movement of the lever is where the phrase “pulling a shot” comes from. After being introduced in 1947 the lever espresso machine now has two variants, the direct lever and the spring piston lever. But, what makes them different?

Spring piston lever: This type of espresso machine works when an internal spring pushes water through ground coffee under pressure. The user pulls a lever downward (i.e. pulling a shot) which forces the spring to compress. When the lever is released, the spring expands and forces the water through the coffee.

While the spring automates the pressure of the water, the barista or person using the machine can control the pre-infusion time as well as the volume of water running through the coffee. They also decide on the exact time to pull the shot. Needless to say, this takes a certain level of skill!

Direct Lever: A direct lever on the other hand doesn’t use a spring to automate the pressure. With this machine, it’s only the “pull” of the barista or user that forces water over the coffee grounds. A skilled barista will be able to change the pressure if they need to. Baristas refer to this skill as “feeling” the coffee which they’re taking a very calculated guess based on a lot of experience. Watching and timing of the pull define the true art of espresso making.

Not all coffee aficionados are sold on the idea of using automatic espresso machines. Manual espresso makers like the Flair Signature Espresso Maker are 100% manual, giving the user complete control over how the espresso turns out.

Another advantage of this nifty espresso press is that it can easily be taken with you to make your favorite drink without needing electricity! A padded carry case keeps your manual espresso maker safe and provides easy storage. A custom pressure gauge gives you an easily readable target espresso range. With the 6 to 9 bar brewing range, even a novice can pull shots like a true Barista!

Semi-automatic vs automatic vs super-automatic

Everything You Need to Know about How Do Espresso Machines WorkOther than the manual options, espresso machines can either be automatic or semi-automatic. The major difference between these two types and the manual version is the amount of guesswork that’ involved.

As I’ve already mentioned in the section above, manual espresso makers require a lot of skill and a good sense of “feel” for when the shot is ready to be pulled. Semi-automatic espresso machines on the other hand take some of the guesswork out of the process because in essence the machine has been partly programmed to know when the brewing process is complete.

Automatic espresso machines control the exact amount of water that’s pushed through to the grounds. Some automatic coffee and espresso machines have digital readings that can assist the barista by allowing for the exact temperature required to be programmed in.

Super-automatic espresso machines are the models that have all the bells and whistles with features and functions that take coffee and espresso brewing to the next level. These types of machines are ideally suited to serious coffee lovers!

Some of the features you could find in a super-automatic espresso maker include the following:

  • Liquid volume control gives the user total control over how much water is dispensed as a programmable function.
  • Pre-grinding while another drink is already brewing.
  • Pre-brewing allows beans to steep before brewing, enhancing the flavor.
  • Temperature control ensures the perfect temperature for each specified drink.

Cleaning tips to prolong espresso machine’s life

Proper cleaning and regular maintenance will go a long way towards prolonging the lifespan of your espresso machine. Generally, espresso machines have a lifespan of 8 to 10 years if taken care of properly. We asked some coffee machine experts to share a few tips to help extend the lifespan of your machine.

Everything You Need to Know about How Do Espresso Machines WorkDaily cleaning

The point of investing in an espresso machine isn’t to add to your daily chores, however, if you want to keep enjoying good, clean coffee the trick is to clean as you go. Cleaning your espresso machine daily applies whether it’s a unit for home use or a larger machine used in a coffee shop for commercial purposes.

Follow these simple steps to get started:

Full backflush: Use a machine brush to scrub and loosen leftover coffee grounds. Use the blind filter together with the detergent specifically designed for your machine. Do this a few times until the water comes out clear. A good idea here would be to pull a few espresso shots to make sure there isn’t any detergent still left in the machine.

Steam wand: The steam wand is a very easy place for bacteria to grow and live. It’s important to purge as well as wipe down the steam wand before and after each espresso drink is made. If possible, let the steam wand soak in a detergent solution overnight or for a minimum of 20 minutes. Remember to remove the tip. Any components soaked in any type of detergent or cleaning solution should be rinsed several times to ensure all soapy residues are washed out.

Draining hose: Avoid coffee ground build-up by thoroughly cleaning the draining hose. This will also keep your drip tray lines from getting blocked. Ensure that you clean the drip tray, portafilters and filter basket.

Regular descaling: Descaling is a term you’ll have to become familiar with if you’re going to own any type of espresso machine. Descaling refers to the removal of limescale build-up in the various components in your espresso maker. Limescale is a hard, chalky, white deposit that if not removed will damage the internal components of your espresso maker. It’s the same as the build-up you find in kettles or pipes. Descaling should take place once every month or when your machine alerts you to do it. Yes, some of the higher-end models notify you by utilizing a flashing light that the unit needs descaling.
If you were curious, here’s a quick vid for hard water and limescale origins:

Clean cloths and brushes: Make sure your cleaning cloths and brushes are fresh and clean. Launder them with detergent and at high temperatures to help eradicate bacteria. Clean cloths will prevent moving bacteria to your espresso machine components. Don’t clean your espresso machine components with the same cloths you use to wipe down your counters or mugs.

What cleaning products should be used?

Different models of espresso machines have different manufacturer’s recommendations for cleaning. Using the incorrect product can cause build-up or even damage to certain components.

A common household mixture to use is vinegar and water. It’s important to rinse all components cleaned by vinegar. The last thing you want is an espresso tasting like vinegar!

Why should you clean out the old coffee grounds?

You might have heard different people emphasizing the importance of cleaning out your old coffee grounds. You might be wondering what the big deal is. Does it matter if you use your espresso machine for a few days without cleaning it? After all, is there a difference between yesterday’s coffee grounds and those of today? The truth is, yes there is!

If you’ve heard of people saying that certain coffee tastes awful or bitter, here’s why. Coffee grounds produce oil. These oils can create build-up and can cause bitter flavors to your fresh coffee. It’s important to flush the group head before every new cup of espresso. It’s also possible for old coffee grounds to create build-up and create bacteria.

Final thoughts

After reading this informative article, I hope you’ll no longer be wondering, “How do espresso machines work?” Knowing the ins-and-outs of your espresso machine will enable you to use it properly as well as maintain and clean it correctly. Understanding the importance of each component and what it does will also help you identify any potential faults or flaws should anything go wrong.

By ensuring your espresso machine is correctly used and maintained, you’ll be guaranteeing yourself many hot and delicious coffee drinks, minus the long queues at the local coffee shop!

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