Want to know more about espresso machines? While they may seem complicated, most espresso machines are quite similar and more straightforward than they appear.
More importantly, knowing how each piece works tells you how it affects the brewing process, making it easier to choose the right machine or maintain them. Let’s get into the details of the espresso machine parts.
20 Parts Of An Espresso Machine You Should Know
Different machines from different brands may offer a few distinct features. However, if we break them down into pieces, they share many similarities in the components.
Here are the twenty main parts of an espresso machine.
* The following parts can be seen in most semi-automatic machines. While Automatic espresso machines also have some of the components below, they are all wrapped inside of the machine and automate the entire process.
1. Water Reservoir
The water reservoir holds fresh water for the machine to turn into a fresh brew. Sizes vary, but the containers on larger machines can reach 75 fluid ounces or more. A good shot of espresso is about two fluid ounces, so you can make quite a few cups from a brewer before you change the water.
A boiler heats pressurized water flowing from the water reservoir via the pump. A larger boiler can produce more drinks in a row, which is ideal if you want several cups of espresso. However, larger boilers also take more time to heat the water inside them, which is less popular for many home buyers.
Not all machines have an actual boiler, some home machines only have one heating element that heats water on demand.
3. Dual Boiler
High-end espresso machines have a dual boiler instead of a single one. The steam boiler heats water to produce steam, while the brew boiler keeps the correct temperature for brewing coffee.
With two separate boilers, baristas can brew espresso and steam milk simultaneously. Dual boilers are more common on high-end home machines and professional environments.
4. Heat Exchanger
Heat exchangers show up mainly on single-boiler machines. These pull some heat from the main steam boiler area, keeping it separate from the water you use for brewing. The extra water is for steaming milk, allowing you to get coffee and steamed milk at once.
Here is a comparison of different types of espresso machine boilers.
The pump pressurizes water and pushes it through the espresso machine. To get through the ground coffee, the machine needs to pump water at about 130 psi, or 9 bars of pressure. Modern brewers use either a vibratory pump or a rotary pump to do this.
While the pumps have their differences, both produce good espresso. Home buyers usually prefer vibratory pumps because they’re cheaper, while coffee shops use commercial machines with rotary pumps for more consistent pressure and reliability.
6. Vibratory Pumps
Vibratory pumps use electromagnetism to pressurize the water. These have a magnet attached to a piston, which are both inside an electric coil. When it gets electricity, the magnet causes the piston to move back and forth, pushing water through the machine. These pumps are small, affordable, and generally replaceable.
7. Rotary Pumps
Rotary pumps are more mechanical than vibratory pumps. These have a motor that spins a disc split into multiple sections. As it rotates, each segment gets smaller, increasing the water pressure. Rotary pumps are quieter and have a longer lifespan than vibratory pumps, but they’re also more expensive and somewhat larger.
Here is a comparison of the vibratory pump vs rotary pump, check it if you want to know more details.
8. Group Head (Brew Group or Brew Head)
The group head is a collection of parts that do most of the work for creating espresso. The function varies slightly depending on head design, but most modern machines use a saturated group head.
Many prosumer machines still use the iconic E61 Group. This E61 design is a mechanically-operated three-way valve where one part lets water in, another moves water into the portafilter, and the last relieves pressure.
Regardless of design, group heads usually offer excellent control over water to let you control how long the water goes through. With practice, this can help create a precise cup of espresso.
9. Filter Baskets
Filter baskets are fine metal grates that can block fine espresso grounds and withstand intense water pressure. You dose coffee in a metal filter basket, distribute them evenly and tamp them down. Pressurized hot water passes through the coffee puck in the filter basket and drips into your cup. They come in different sizes, including 51 mm, 54mm, or 58mm. Each portafilter basket has its own capacity, for a single, double or triple shot.
A pressurized filter basket has only one hole at the bottom. This allows you to use a coarser grind but still have enough resistance to extract coffee and create crema.
A non-pressurized basket has hundreds of holes instead of one, which requires a more accurate grind size.
Check our guide if you want to know more about the difference between pressurized vs non-pressurized baskets.
A portafilter is a handle that holds the filter basket, allowing you to move it in and out of the machine easier. Portafilters typically have a spout for helping espresso pour out, a spring clip to keep the filter in place while your brewer is in use, and sometimes a gauge for checking the water pressure.
A bottomless portafilter doesn’t have a spout, so you can observe and troubleshoot the espresso shot via the bottom of the basket directly.
Should you get one? Check this: Why use a bottomless portafilter?
11. Steam Wand
The steam wand dispenses hot water to quickly steam milk and get it to the right temperature and texture. The wand is mainly relevant if you’re making a milk-based espresso drink, such as a cappuccino.
A beginner espresso machine usually comes with a Panarello wand which makes thicker and foamier milk froth. Better machines use pin-hole steam wand for more silky microfoam for latte art.
12. Steam Tip
The steam tip is on the very end of the steam wand. This tip is what dispenses the steam into specific patterns, allowing you to steam milk properly.
You can find steam wand tips with one, two, or four holes. For beginners, one hole tip is easier to get the optimal texture, while more holes are more efficient.
13. Hot Water Spout
A hot water spout dispenses hot water directly from the boiler, allowing you to add it to drinks or use it to clean cups and other things. Not all automatic espresso machines have a hot water spout. Some integrate it with the steam wand.
Grinders grind coffee beans to get them to the right size for brewing. However, the best coffee grinder for espresso can grind fine enough but also offers room for minor adjustments.
Or you can choose espresso machines with grinder, so you don’t need to invest in an extra one.
15. Bean Hopper
A bean hopper holds coffee beans and feeds them into the grinder when you’re ready to make coffee. Most hoppers are plastic, but durable glass options are also available for some machines. Some espresso machines do not have hoppers or grinders, but some do.
Bean hopper sizes vary, but most hold up to a few days worth of beans.
The Proportional Integral Derivative is a simple digital temperature controller that helps control the parts and keep the water at a set temperature. They have a temperature probe inside the boiler to get information and make adjustments.
Most dual boiler machines feature a PID in each boiler to keep the water in the optimal temperature range. PIDs come with a digital display and let you adjust things like the water temperature.
17. Shower Screen
The shower screen helps distribute water evenly over the compacted coffee grounds inside the portafilter. If water isn’t distributed evenly, it could result in a messier, lower-quality drink. Shower screens require occasional maintenance and replacement, as the buildup of minerals and particles within them will eventually affect their performance and the final taste of your espresso.
18. Drip Tray
Drip trays sit beneath your cup to help catch water, falling dregs, and any splashing that may occur. Most espresso machines come with a drip tray by default, and they’re easy to clean with just a quick rinse. You shouldn’t need to replace this unless it sees a ton of use, but if you do, ensure you get one that fits your machine.
19. Pressure Gauge
Pressure gauges are usually on the front of an espresso machine. They have two needles indicating pressure. One shows the boiler pressure, while the other shows your pump operating pressure. Watching these can help alert you to any problems with your brewing.
Remember, about nine bars are ideal for producing espresso. As a general principle, higher pressure means more extraction from the coffee grounds. Too much pressure can negatively impact the flavor. Lower pressure tends to get better flavor as long as it’s enough to get the water through the grounds.
Many entry-level machines don’t have a pressure gauge.
20. Control Panel
Depending on the espresso machine design, the control panel can be a touch screen, a few buttons, or a lever.
Control panels include a selection of functions and controls that let you adjust what you’re making. These frequently allow you to choose whether you’re making a single or double shot of coffee and whether you’ll use the steam wand. Some control panels are button-and-dial only, while others have digital controls.
On advanced models, control panels can adjust things like water pressure and temperature. Beginners should stick with the default settings, but once you understand your machine, this is one of the main ways to alter the flavor of a drink.
Now that you know the espresso machine part names, you’re ready to get to work brewing the perfect cup. If you’re not sure where specific espresso machine parts are on your machine, check the manual. Most manufacturers have diagrams indicating the major components, so you shouldn’t have any trouble finding them.