Portafilters and Filter Baskets (All the Details!)

Portafilters and filter baskets are essential for making espresso. While they might seem simple and all similar, there are major and minor details that can make a difference in your at-home coffee experience.

If you have recently purchased an espresso machine or are looking to upgrade one, here’s what you should know about portafilters and filter baskets.

What is a Portafilter?

The portafilter is the espresso accessory that holds the filter basket, and locks into the espresso machine’s group head. Portafilters consist of a circular holder and a handle; some also have a spout or backpressure valve.

Portafilter vs. Basket

The portafilter is the accessory that holds the filter basket, letting the basket sit in the circular portion of the portafilter. The coffee grounds go into the basket when prepping a shot, and then the basket goes into the portafilter.

The filter basket has a thin semi-circle around its upper rim. This sets on top of the portafilter’s edge, thus holding the basket in place. All baskets are held by this upper edge, and don’t sit on the bottom of the portafilter.

Sometimes portafilters and baskets are simply referred to as portafilters, since they’re always used together. They technically are two distinct accessories.

Portafilter vs. Grouphead

The portafilter is the accessory that locks into the group head. The group head is the part of the espresso machine that water exits from, flowing into the filter basket that’s held in the portafilter.

Most portafilters have two small edge pieces that are slightly wider than the actual basket-holding portion. These pieces slide into slots that the group head has, and then they move into a little tunnel as the portafilter is rotated. This locks the portafilter in place.

A portafilter is needed in order to form a secure seal around the filter basket, so pressure can be maintained while the espresso shot is pulled. The portafilter’s handle also makes it easier to load than just a basket would be.

What Are the Different Types of Portafilters?

The most common type of portafilter is a non-pressurized version, which itself comes in a couple of different styles. There are several other types of portafilters that can be helpful for certain applications, though.

Non-Pressurized Portafilter

Non-pressurized portafilters are the traditional type of portafilter, and continue to be the most widely used. Don’t assume their simple design is inferior to other types. Non-pressurized will make the best espresso.

A non-pressurized portafilter consists of only the filter basket holder and the handle. They hold the basket in place but do little else — the pressure needed for brewing espresso is generated by passing hot water through fine coffee grounds.

Because the grounds are what actually build pressure, a non-pressurized portafilter requires a good grinder and a tamper. Upgrading to an espresso-specific grinder will make a significant difference in shot quality with these portafilters.

Spouted Portafilter

Spouted portafilters are non-pressurized portafilters that have a spout at the bottom. The spout may be a single spout or a double spot, with the latter being able to split shots for making two drinks at once.

The main advantage of a spouted portafilter is that it controls messes when shots go awry, which they will occasionally. The bottom and spout on these portafilters generally limit them to single or double baskets (see Portafilter Basket Sizes).

The spouted non-pressurized portafilter is the most traditional type, and is almost universally used in cafes. A spouted portafilter will serve you well if you have a decent espresso machine and grinder.

Bottomless (Naked) Portafilter

Bottomless (naked) portafilters are non-pressurized portafilters that don’t have a spout at the bottom. The bottom is “naked,” which allows espresso to flow directly from the basket into a cup.

Bottomless portafilters allow you to assess grounds preparation more thoroughly, as you can see how espresso flows out o the basket. They also can accommodate triple baskets (see Portafilter Basket Sizes) because there’s no bottom, and have a more compact design so there’s extra room for fitting a mug below the portafilter.

The bottomless portafilter is preferred by home baristas who like to overdose their espresso, giving shots more volume and/or stronger flavor. You might also choose this option for its slimmer profile.

Rocket Espresso 58mm Bottomless Portafilter
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Pressurized Portafilters

Pressurized portafilters have a valve that creates backpressure as espresso flows out of the basket. A double-wall structure has a space where espresso collects, to create the pressure needed for brewing and making crema.

Because pressurized portafilters actually generate pressure, they can be used with coffee that’s less precisely ground. The portafilters will even work with standard coffee grinders.

Some pressurized portafilters have less conventional designs, but they work the same way. All have a bottom that usually limits the portafilter to single or double baskets. As an example of a different design, look at the Uniterra Nomad that uses a drawer as a portafilter.

If you don’t have an espresso grinder, a pressurized portafilter will consistently pull quality shots with just a standard coffee grinder. If you have an espresso grinder, a non-pressurized portafilter will pull more vibrant and flavorful shots. A tamper is still needed to prepare espresso with a pressurized portafilter.

Gaggia Classic Portafilter Filterholder with double 14g. pressurized basket (21000491) & Spout
  • Gaggia - Portafilter with double spout, 2 cup 14g. pressurized basket (21000491) and two way pin for perfect cream.
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Pod Portafilters

Pod coffee brewing was made popular by Keurig, and Nespresso is a popular brand that makes espresso pods.

Pod portafilters hold a prepared capsule of espresso, which could be likened to a prepackaged tea bag. The pod is loaded into a specialized portafilter that’s usually built into the espresso machine. Machine’s portafilters may be compatible with name-brand and third-party espresso pods.

Between Keurig and Nespresso, Nespresso makes much more espresso-like coffee. Keruig essentially extracts like a drip brewer, making “espresso” by using less water and/or more grounds so that the brew is stronger. Nespresso espresso machines use centrifugal force to create some pressure when brewing.

All pod portafilters (including Nespresso) remove any control you have over grounds preparation and brewing, and will brew inferior espresso if compared to non-pressurized or pressurized portafilters. Completely automating the brewing process provides maximum convenience and requires no experience, though.

Adapter Portafilters

Adapter portafilters can function as either non-pressurized or pod portafilters. They’re constructed much like non-pressurized ones, but have an adapter for use with pods.

Only select machines have adapter portafilters that can be used with them, and a machine-specific adapter might be needed.

The adapter setup allows for the convenience of pod espresso when you’re in a rush, and the hands-on experience of tamping and pulling shots when you have a more leisurely schedule. It might not perform quite as well as a traditional non-pressurized portafilter, but most should be fairly comparable in shot quality.

If an adapter portafilter is something you’re interested in, you may have to specifically look for a machine that’s compatible with them. Contact the manufacturer to find out whether there’s an adapter available for any current machine that you already have.

How Do I Choose a Portafilter

There are three variables to consider when choosing a portafilter, and they should be taken in order. Prioritize size, then style and then look.

A Size That Fits Your Espresso Machine

You must use a portafilter that’s the same size as your espresso machine’s group head. Sizes are the diameter as measured in millimeters, and you should go by the manufacturer’s stated sizes rather than trying to measure them yourself.

Check your espresso machine’s manual or the manufacturer’s website to find out what size group head the machine has. While you can check a portafilter’s size if you already have one that fits well, it’s usually easier to find espresso machine information.

What is the Standard Portafilter Size?

The standard portafilter size for commercial espresso machines is 58 mm, and higher-end home machines sometimes use this size. Many home espresso machines (including some high-end ones) use smaller portafilters, however.

Common home espresso machine portafilter sizes range from 49 mm to 58 mm. A few models might be slightly smaller or larger, but they’re outliers. See the chart at the end of this article.

Are Portafilters Universal/Interchangeable?

The actual mechanism by which portafilters lock into place is pretty universal. So long as portafilters are the same size, they should be interchangeable.

Portafilters must have the same diameter, and switching out pressurized/non-pressurized ones might have negative results. The different types sometimes can be changed out with each other, though, and there’s no issue switching spouted/naked portafilters.

The few models that don’t have interchangeable portafilters usually have odd sizes that aren’t within the common range of 49 to 58 mm, or have an obviously unconventional portafilter design.

A Type That You Prefer to Use

Within the scope of what your machine accepts, choose whatever type of portafilter has the advantages that you want most. You can freely switch between spouted and naked if using non-pressurized ones. A few machines can accept non-pressurized or pressurized, but you should first check the owner’s manual or manufacturer’s website.

A Style That You Like

The handles of many portafilters unscrew and can be changed out with another handle. Wood portafilter handles are readily available, and other aesthetics are also available. You could even get a portafilter handle engraved if you like.

You usually don’t have to worry about whether handles will fit into metal holders, as most are a fairly typical screw. You might want to double-check with the handle maker before purchasing, however.

Because a fancy portafilter handle is far from necessary but fairly affordable, this makes a good present for a home barista. A setup with matching wood portafilter handle, tamper handle and knock box looks especially sharp on the counter. (Get a matching cart and wood-accented espresso machine for the ultimate Pinterest-worthy setup.)

What Are the Different Types of Portafilter Baskets?

Portafilter baskets have a pretty straightforward design, but they can differ in how precisely they’re made. Although you probably won’t notice much difference between standard and competition filter baskets, the latter can brew minorly better espresso.

Standard Portafilter Baskets

Most espresso machines come with standard portafilter baskets, and any basket that’s not specifically “competition” is a standard basket. These baskets work fine for virtually all home use.

You can probably tell whether you have a standard by performing a basic visual inspection. Look at the perforations in the bottom of the basket, and you’ll likely see minuscule defects. A hole might not be fully punched through, or the occasional edge might not be perfectly clean.

These defects do have an impact on water flow, and therefore extraction. You must be perfectly grinding and perfectly tamping in order for a basket defect to have any measurable impact on shot quality.

Competition Portafilter Baskets

Competition portafilter baskets might have a slightly different hole pattern, but the primary difference lies in the tolerances allowed during manufacturing. Stricter tolerances create a more uniform product. In this case, a more uniform bottom perforation.

Look closely at the bottom of a competition portafilter basket, and you shouldn’t be able to see any holes that aren’t punched or uneven cuts. These baskets should allow water to flow as evenly as is possible.

Only consider a competition portafilter basket if you already dial in the grind, tamp to a specific pressure and monitor your water temperature. Once all of these other variables are attended to, then a competition basket could make your shots a small amount better.

What Are the Different Portafilter Basket Sizes?

Portafilter basket sizes must be considered in terms of both diameter and depth.

Portafilter Basket Diameters

The diameters of portafilter baskets follow those of portafilters, and a basket will fit in the same size portafilter. As is true with portafilters and group heads, you should rely on manufacturers’ stated dimensions rather than measure them yourself.

A 58 mm portafilter basket should fit in a 58 mm portafilter. The same is true for a 49 mm basket and 49 mm portafilter.

In rare cases, some older model espresso machines might be minorly different than the basket diameters that they purportedly are compatible with. This is primarily due to minor differences in manufacturing tolerances.

If a basket is supposedly the right size for a group head but seems hard to lock in place, sometimes the very edge of the basket’s rim can be sanded down. A power sander or a few minutes of hand sanding occasionally will shave off just enough for an easier fit.

Portafilter Basket Depths

Portafilter baskets come in varying depths, but depth usually isn’t measured as precisely as diameter.

Sometimes portafilter depths are referenced by how many shots they’re intended for, with single, double and triple baskets all being available. Shot size provides only a rough measurement, as shots can be pulled with different coffee ground doses.

Measuring portafilters by how many grams they hold is somewhat more precise. The method still isn’t perfect, however, as bean density and grind size affect the weight-volume ratio. You can also fudge the grams dosed slightly, by either overdosing or underdosing shots if you prefer.

You don’t have to be concerned with basket depth if you use a bottomless portafilter, as the design of these portafilters specifically accommodates baskets of any depth.

If you use a spouted, pressurized or any other portafilter, make sure that the basket isn’t too deep for the portafilter. The best way to check this is by asking the manufacturer and reading others’ comments.

Chris’ Coffee has an excellent selection of baskets.

Using a Portafilter

Loading a portafilter with a basket and locking the portafilter into place is simple enough. A couple of finer points can influence extraction and shot quality, however.

Should You Tamp Grounds in a Portafilter?

The best practice is usually to tamp grounds in the basket when the basket isn’t loaded into the portafilter. This keeps any spout or valve on the portafilter from causing an uneven tamp, and it’s easier to hold/feel the basket when it’s not sitting in a portafilter.

You also should remove the basket from the portafilter for between-shot rinsing (see How to Clean), so tamping in just the basket doesn’t add any work.

Should You Preheat a Portafilter?

Whether you should preheat a portafilter is a much more complicated question, and you could even decide that cooling the portafilter is preferable at times.

The reason to preheat or cool your portafilter is to maintain a consistent and correct brewing temperature when pulling espresso. On home espresso machines, altering the portafilter and group head temperatures are the most effective ways to manage brewing temperature.

The group head will initially be cool, but the water that flows through will quickly heat the group head as more shots are pulled. Many home espresso machines’ group heads are a little too cool when pulling the first shot, but then quickly become hotter than is wanted for brewing espresso. You may notice shots become more bitter after pulling a few back-to-back.

The portafilter will be room temperature, which is substantially lower than espresso brewing temperatures, when you initially load it into the group head. Most espresso machines have more mass in the group head than the portafilter, however, so heat will quickly transfer from the group head to the portafilter.

Think of the group head as primarily influencing brew temperature, and the portafilter influencing the group head. This is essentially how the two interact because of the difference in masses.

Thus, you can use the portafilter to counter some of the group head’s temperature as you see fit. The group head may not be warm when you first turn on your espresso machine, so you can preheat the portafilter to provide some warmth. As the group head heats with successive shots, you can cool the portafilter so it brings the group head’s temperature down some. (On some models, you can warm the machine up by cycling water through the group head without actually pulling a shot.)

A small bowl of hot water or ice water works well for altering the portafilter’s temperature.

Portafilter Accessories

Many smaller accessories must be or can be used during grounds preparation. These include a tamp, a dosing cup, a dosing funnel and a distribution tool.

What is a Tamper?

A tamper is used to compress grounds in the portafilter basket. The tamper ideally should be just smaller than the basket, so that the tamper fits without room around its sides.

You can make do with a tamper that’s slightly too small, but extraction will suffer because you won’t be able to tamp the edges well. A tamper that’s significantly smaller than the basket won’t work well.

What is a Portafilter Dosing Cup?

A portafilter dosing cup helps reduce how many espresso grounds get on the counter rather than in the portafilter basket. This doesn’t just reduce waste, but it also ensures a more accurate weight measurement of the grounds in the basket. No grounds are lost in the dosing process.

You grind directly into a dosing cup, and then place the basket on top of the dosing cup. The fit doesn’t need to be perfect, but it’s good enough that grounds don’t spill onto the counter when you flip the two parts. Most baristas place the basket in the portafilter before using a dosing cup, simply because the handle makes holding everything either.

Some dosing cups have specially designed lips and/or antistatic treatment that further reduces lost grounds. The most important aspect is that the dosing cup fits your espresso grinder, though.

What is a Portafilter Dosing Funnel?

A portafilter dosing funnel is also used to prevent grounds from spilling when they’re poured into the portafilter basket. The funnel sits atop the basket and channels grounds into it, rather than dumping them when turning over as is the case with a cup.

A dosing funnel won’t prevent static electricity from keeping some grounds stuck to the sides of the grinder’s chamber, which a cup will do.

The higher sides of a funnel make it possible to use a distribution stirrer (see below) without spilling, even if the basket is overdosed. A cup won’t keep grounds from spilling during distribution.

Many companies that make dosing cups and dosing funnels sell these two accessories together. You can use a cup or a funnel on its own, but they’ll be most effective if used together. A funnel has to be the same size as your portafilter.

What is a Portafilter Distribution Stirrer?

A portafilter distribution stirrer is a tiny rake that’s drawn through the espresso grounds to improve distribution. The rake both spreads out grounds so that they’re even, and breaks up any clumps of grounds that are in the basket. This second benefit makes a distribution stirrer preferable to tapping, finger leveling and other distribution techniques.

Any distribution stirrer will work with any non-pressurized portafilter. The accessory is only needed if you’re at the point that a competition basket is also a worthwhile upgrade (see Competition Baskets).

Portafilter with Pressure Gauge

You need to have the right pressure to get the best espresso shot. If your espresso machine doesn’t have a gauge built-in, you can pick up a portafilter with a pressure gauge instead. This will tell you precisely the pressure at the grouphead so you can adjust accordingly.

Portafilter Maintenance

Portafilters are fairly basic and don’t require much attention, but there are a few simple maintenance items to know.

How Do You Clean a Portafilter?

Portafilters can be rinsed with warm or cold water between shots. Separate the basket and portafilter after rinsing so that you can thoroughly dry both. Any water that somehow gets onto the edge or bottom of the basket could cause channeling and interfere with extraction.

After making beverages, portafilters can be washed with warm water and soap. You don’t want to use any abrasive sponge that could rub off the portafilter’s finish, but there’s also no need to when you’re just washing off old espresso and grounds.

Can You Put a Portafilter in the Dishwasher?

Most portafilters are made of metal, and can be safely washed on either the top or bottom rack of a dishwasher.

Be sure to unscrew the handle before putting the metal holder in the dishwasher. Plastic and wood handles might not be dishwasher safe, and water can seep between the holder and the handle. Only wash the holder, and dry it thoroughly before reattaching the handle.

When Should You Replace a Portafilter?

Portafilters tend to be quite durable and rarely have to be replaced.

If you switch to a new espresso machine that has a different group head size, you’ll need to purchase a different portafilter. You also might purchase a different type of portafilter.

You likely won’t have to actually replace a portafilter because it breaks. Some can become worn around the edges where they lock into a group head, and handles occasionally do break. But, these issues usually only happen after years of regular use.

If you notice a portafilter is visibly damaged or doesn’t seem to sit properly in the group head, it’s possible that the portafilter has to be replaced. There’s little reason to worry about these maintenance items, though.

Common Home Espresso Machine Portafilter Size Chart

Astoria 58 mm
Azkoyen 58 mm
Bezzera 58 mm
Brasilia 58 mm
Breville (new models) 58 mm
Bunn 58 mm
Caramati 58 mm
Cimbali Junior 58 mm
Cimbali Casa (varies) 58 / 57 mm
Conti 58 mm
ECM (most models) 58 mm
Elektra 58 mm
Espressione Cafe Retro 58 mm
Expobar 58 mm
Fiorenzato 58 mm
Futurmat 58 mm
Gaggia Classic & Semi-Auto 58 mm
Grimac 58 mm
Isomac 58 mm
Kitchenaid Proline 58 mm
La Marzocco 58 mm
La Pavoni Scala 58 mm
La Valentina 58 mm
Nuova Simonelli (most models) 58 mm
Pasquini Livietta 58 mm
Rancilio (most models) 58 mm
Rocket 58 mm
Quickmill 58 mm
Ascaso 57 mm
Cinbali Casa 57 mm
Francis (older models) 57 mm
Innova 57 mm
Lelit 57 mm
La Pavoni Napolitana 57 mm
Astra 56 mm
Aurora 56 mm
Francis (newer models) 56 mm
Reneka 56 mm
Mokita 55 mm
Miscellaneous older models 54 mm (former standard)
Breville Express & Infuser 53 mm
Espressione Care 53 mm
Estro 53 mm
Faema 53 mm
La Pavoni Lusso 53 mm
La Spaziale (commercial models) 53 mm
Mypressi Twist 53 mm
Saeco 53 mm
Solis 53 mm
La Spaziale (home models) 52 mm
Starbucks Barista 52 mm
Bodum Granos 51 mm
Breville 800 Series 51 mm
Cuisinart 51 mm
Delonghi (new models) 51 mm
Gaggia Factory Lever 51 mm
Smeg 51 mm
La Pavoni Lever 49 / 51 mm (varies)
Rok 50 mm
Delonghi (old models) 49 mm
Olympia 49 mm