As more and more people opt to make their daily coffee in their kitchens, the demand for elevated setups is growing—particularly espresso makers, which call for portafilters.

Not all portafilters are created equal, though, so it's worth doing your research.

What is a portafilter, exactly? What's it for, and how do you know what kind to get? Keep reading for answers to these questions and an overview of the different types of portafilters for consistent extraction.

What is a portafilter?

A portafilter is a critical part of an espresso machine. The filter basket holds ground coffee and goes into the espresso machine's group head. (The group head is the component that sends hot water through the coffee during espresso brewing.)

What does a portafilter do?

A portafilter is where ground coffee goes in an espresso machine. It locks into the group head, which forces hot, pressurized water through the ground coffee. This process extracts flavorful espresso that pours out from the bottom of the basket to create a concentrated espresso shot with more solids for a bolder mouthfeel than traditional drip coffee.

Anatomy of a portafilter

Roughly the size and shape of an ice cream scoop, a portafilter comprises a small metal filter basket (much smaller than filters used for drip coffee) and a handle.

Some designs also have a spout (often called a spouted portafilter), which directs the espresso down into the cup, while others are "bottomless" with no spout. You might also find portafilters with spring clips, which attach the basket to the metal ring at the end of the handle.

Bottomless (naked) portafilters 

Bottomless portafilters don't have a spout or second wall, so the filter basket is visible when you look up toward the group head. Also called naked portafilters, the open-bottom design lets you see the espresso as it extracts from the compressed espresso grounds in real time.

Why baristas and home brewers love bottomless portafilters

Many baristas and seasoned home brewers prefer bottomless portafilters. Why? When you're able to directly see the espresso flowing out, you can identify various issues, like uneven extraction in areas where there's less pressure from an improperly packed puck (called "channeling").

This allows you to fine-tune your tamping technique and ensure you're getting the most consistent, flavorful shots of espresso—often with more crema than a pressurized basket. Without a spout at the base, a naked portafilter can be easier to clean.

Though the pieces are easy to clean, using a bottomless portafilter can get messy, as it's more prone to splashing. This type of portafilter might not be the best choice for beginners since properly tamping and identifying extraction issues requires a certain skill level and knowledge of espresso making. But with research and practice, anyone can do it.

Pressurized and non-pressurized portafilters

As for portafilters with bottoms, they can have pressurized or non-pressurized baskets. Let's review how they differ and what they're best for in espresso extraction:

● Pressurized portafilters – Sometimes called dual-wall filters, these have inner walls with lots of holes at the base and an outer wall with just one small hole. The smaller hole creates pressure to make up for inconsistencies in the grind size or uneven tamping. This is ideal for beginners. Thanks to the extra pressure, you can count on a consistent flow rate and rich crema at the top of each espresso shot.

● Non-pressurized portafilters – Non-pressurized (or single-wall) portafilters have just one wall with many holes at the base. They call for finely ground coffee and a precise tamping technique (flattening the ground coffee into a compact, even "puck"). Getting the right grind size and evenly packing down the coffee can be tricky, but it creates the pressure needed for optimal espresso extraction and professional-level shots with perfect crema.

Spouted portafilters

Spouted portafilters have one or two metal spouts at the base. The spouts help the brewed espresso flow into cups with less splashing and minimal mess. With a double-spout portafilter, you can extract espresso simultaneously and dispense it into two separate cups.

Portafilter size and material matter

When buying a portafilter, pay attention to the size and material. 

Common portafilter sizes

The most common sizes for portafilters are 54mm (millimeters), 49mm, and 58mm. Home espresso machines often use 54mm or 49mm, while 58mm is standard for coffee shops and cafés. The portafilter size affects how much ground coffee to use, so make sure you know what size you have.

Stainless steel vs. brass vs. aluminum

The best portafilters are usually stainless steel, a durable material with good heat retention that washes easily and resists rust. You'll also find options made of brass or aluminum. The handles are typically wood, so they don't get too hot as the metal component heats up.

Choosing the right portafilter for you

Once you determine what type of portafilter best suits your skill level and personal preferences, you can choose one for your espresso machine—just be sure you get the proper size.

For specialty coffee right at home, explore espresso machines from Breville. We also have a range of espresso accessories, including naked portafilters, tampers, dosing funnels, tamper mats, espresso glassware, and more.

Sources: 

1. Archive Market Research. Espresso Portafilter Machines Navigating Dynamics Comprehensive Analysis and Forecasts 2025-2033. https://www.archivemarketresearch.com/reports/espresso-portafilter-machines-484077#

2. MarkWide Research. Espresso Portafilter Machines Market Analysis– Industry Size, Share, Research Report, Insights, Covid-19 Impact, Statistics, Trends, Growth and Forecast 2025–2034. https://markwideresearch.com/espresso-portafilter-machines-market/

3. Specialty Coffee Association. Defining the Ever-Changing Espresso. https://sca.coffee/sca-news/25-magazine/issue-3/defining-ever-changing-espresso-25-magazine-issue-3

4. CoffeeGeek. Ten First Steps for a New Espresso Machine. https://coffeegeek.com/guides/feature-guides/10-essential-first-steps-new-espresso-machine-guide/

5. Perfect Daily Grind. Espresso Machine Mods: 4 Reasons to Use a Naked Portafilter. https://perfectdailygrind.com/2016/03/espresso-machine-mods-4-reasons-to-use-a-naked-portafilter/

6. Perfect Daily Grind. Why a Messy Naked Portafilter Means Bad Extraction. https://perfectdailygrind.com/2016/10/video-why-a-messy-naked-portafilter-means-bad-extraction/

7. Encyclopedia of Food and Health, 2016. Espresso: The Brew—Extracting for Excellence. https://www.sciencedirect.com/topics/food-science/espresso

8. Bangladesh University of Business and Technology. Stainless Steel Coffee Maker: The Ultimate Guide to Choosing the Best Brew. https://www.researchgate.net/publication/388637136_Stainless_Steel_Coffee_Maker_The_Ultimate_Guide_to_Choosing_the_Best_Brew

9. International Conference on Industrial Engineering and Operations Management. Product Design and Experiment on Espresso Machine Portafilter Using Reverse Engineering and VDI 2221 Methods. https://ieomsociety.org/proceedings/2022istanbul/378.pdf