Bottomless Portafilter – Why Do You Need One and Where To Buy It?

The pursuit of the perfect espresso shot is a non stop race.  Professionals and enthusiasts alike try to improve the extraction down to the finest details. No wonder there are so many tools and accessories for espresso brewing, espresso lovers are truly passionate.

One of these espresso tools is the bottomless portafilter. In this page we will show how a bottomless portafilter can help you improve your espresso extraction, and where to buy one. We will tell you as well when you don't need to buy a bottomless portafilter.

What is a Bottomless Portafilter?

A bottomless portafilter, (sometimes called naked portafilter), is a portafilter that has the bottom side open, exposing the filter basket. This allows a clear view of the extraction process, thus giving the real time information about possible flaws in the puck preparation.

A regular portafilter is a solid spouted cup. The espresso extracts in the portafilter's cup, and from there it pours through the spout into the demitasse. 

On the bottomless portafilter the espresso pours through the filter basket directly into the cup. This gives the barista a clear view of the pour, and allows them to make adjustment on subsequent shots. 

portafilters and filter baskets
Bottomless portafilter and side by side with a set of filter baskets.

Benefits of Using a Bottomless Portafilter

The main purpose of a bottomless portafilter is to allow the barista to improve the extraction, and to perfect their shots. It does that by providing more information about the coffee being extracted. With this extra information, it's easier to troubleshoot and see irregular patterns in your extraction process. I'll expand on that in a bit. This information is also critical for beginner baristas, for understanding the espresso extraction, so we can say one other benefit is educational

Another important reason is cleaning. In a standard portafilter, coffee oils accumulate beneath the filter basket and above the spout. This requires regular maintenance, on top of your regular descaling and backflushing. 

You can use a larger basket size. It is not uncommon that the regular portafilter doesn't accommodate a triple basket. An open end will allow the triple basket to stick out. 

The spouted portafilter takes away the space between the spout and the cup. With more compact machines this would be a problem, so much so that you can't fit a scale, under the demitasse. The bottomless portafilter gives you a bit more clearance, which sometimes is all you need to fit a larger mug for a latte

There is another common reason people switch to a bottomless portafilter – the aesthetics. Let's admit it, looking at the nice stream of coffee coming out of your portafilter it's quite satisfying, and I personally can't get enough of it. Be warned though, using a naked portafilter is cool, but it's not easy. 

How a Bottomless Portafilter Helps You Pull Better Shots?

This is the main point of using a naked portafilter. If this is not your main reason, I don't suggest you buy one, because this is a rabbit hole. You have to be passionate, or work in the industry. There is a considerable learning curve, and it might get frustrating. This is the step up for the perfect espresso shot. I will talk about the pros and cons of the naked portafilter in a dedicated section. Let's see now, how this cool looking accessory can improve our shots. 

The biggest advantage, as we said before, is the bottom side open, which in turn allows open view of the extraction process. By examining the pour, you can get important info on how to adjust your tamping and distribution to improve that flow. Here a few things you can examine with  bottomless portafilter.

  • Firstly, you can examine the color and texture of the espresso as it brews. Does it have enough crema? Is it too thin? Does it have tiger stripes? Does it blonde too fast?
  • You can also look at the flow pattern, and if it flows on streams, or on the side, this means you have channeling. This is probably the most important aspect for advanced baristas. Maybe get a better , or improve your puck prep. 
  • Does it spray? If it does, then there is major channeling happening there, and you might need some additional espresso tools to prep your shot. Maybe a WDT tool, a puck screen, etc… 
  • This can help you quickly identify if your tamping technique is off or if there are any issues with the portafilter basket. Additionally, bottomless portafilters are often easier to clean than spouted portafilters since there's no spout to get in the way.

Another advantage of using a bottomless portafilter is that it can help you achieve tiger striping. Tiger striping is a visual effect that you can see when the espresso is being extracted properly. It looks like alternating dark and light lines running through the espresso. This is a sign of a well-extracted espresso with a good balance of flavor and crema.

In conclusion, if you're an intermediate or advanced espresso enthusiast or barista, a bottomless portafilter is a valuable tool to add to your arsenal. It can help you troubleshoot any issues with your extraction process, examine the color and texture of the espresso, achieve tiger striping, and make cleaning easier. So, try using a bottomless portafilter and see the difference it makes in your espresso game.

Naked vs. Spouted Portafilters – Pros and Cons

portafilters and filter baskets
Bottomless portafilter and spouted portafilter side by side

The most common portafilters are the dual pouted ones. This allows you to pull two espresso shots at the same time, in two . There are single spout portafilters for some espresso machines, but most model come with a double spouted one. 

For those who need a double shot, or a triple shot in the same demitasse, this could be a problem. It is not uncommon to see one of the coffee streams pour outside of the cup. Just a little misalignment and the pour flows on the outside of your espresso cup. A naked portafilter pours in a single stream, so it does solve this problem. But if you need to pull many small shots for a party, you'll have to dust off the old double spouted portafilter. 

The biggest problem with bottomless portafilters is that they can make a mess. If your technique is off, you will end up with coffee spraying all over your kitchen. It takes a bit more expensive equipment, and some more puck prepping tools to avoid catastrophic channeling. While you can raise the cup just under the filter basket to cover eventual spraying streams, fixing your technique is the right way to do it. 

A minor issue with closed-bottom portafilters is the extra contact of the shot while pouring out. This breaks the crema, and if the portafilter is not properly maintained, coffee sediments can transfer into your beverage. Coffee brewed with a bottomless portafilter is fluffier, and foamier because of that. 

The biggest disadvantage of the bottomless portafilter is the high skill level it requires.  The lack of a bottom will expose problems with channeling but in the process it  could spray and splatter all over your kitchen. Trust me, I know this from experience. While my skills and puck prep evolved since then, the first two shots with a naked portafilter made a disaster in my kitchen.

However, if you're looking to take your espresso game to the next level, a bottomless portafilter is a great way to get more insights about your extraction.

I hear often times the question: “How much coffee holds a naked portafilter?” It's not the portafilter that holds the coffee, it is the filter basket. So it depends on the filter basket. Some spouted portafilters are not deep enough to fit a triple shot basket. This isn't a problem with bottomless portafilters, since the bottom is open, and the basket can be as tall as you want.

Are bottomless portafilters better than the spouted ones? We can't say it's better, but it does have its advantages, which might make it slightly more appealing to many baristas.

Brewing with a Bottomless Portafilter

Brewing espresso can be a complex and nuanced process, especially when using specialized equipment like a bottomless portafilter. In order to achieve the perfect espresso shot, it's important to understand the espresso extraction process, tamping technique, and other key factors. Let's take a closer look at some of the other aspects of pulling shots with a naked portafilter.

spraying because of channeling
Bottomless portafilter spraying because of channeling. This is an obvious puck prep miss.

Tweaking Brewing Variables when Using a Bottomless Portafilter

I mentioned before that if you don't prep your coffee puck properly you might get a disaster in your kitchen. In this section I'll go briefly through all variables that matter for the extraction, and link to more detailed guides for each of them. Let's get to it. 

Grind Size

There are two factors when talking about grind size. The grind size itself, which is something that the barista tweaks until they get the best shot. The consistency of the coffee grounds is also important. If your grinder doesn't give you a consistent grind size and it gives you dust and boulders, you will need to change it. We have an article where we recommend some of the best espresso grinders on the market. Grind size problems will show as an abnormal flow rate, (too slow, or too fast).

Tamping Pressure and Technique

Tamping errors will be the most obvious when using a bottomless portafilter. If you tamped sideways, you will see coffee flowing on a half of the filter basket. Pressure is also important as it creates the necessary puck resistance. Applying even pressure on the tamper ca be trained, but you can look at some of the leveling tampers we have in our guide, for a shortcut. If you want to do it the hard way, look at our tamping tutorial, that should help you start your training. 

Dose

The amount of coffee used depends on the filter basket you are using. The dose in the basket is set by the manufacturer, and when you buy a new naked portafilter it might come with a double basket and a triple basket. Don't try to guess, they vary from manufacturer to manufacturer. A double basket can be designed for anywhere from 14 to 18 grams, and a triple basket anywhere from 20 to 22 grams. 

Distribution

Distribution is the most common reason for spraying. Use a WDT tool, and we talk about the WDT more on a separate page, it's almost mandatory with a bottomless portafilter. If coffee clumps together, these clumps will form dry pockets, where water doesn't reach. Clumping is more common with cheap espresso grinders. 

However, when you have channels forming in the puck, those are going to be used by the hot water to travel through, and that is the main reason for spraying. 

Where to Buy Bottomless Portafilters

The best place to buy a portafilter is from your espresso machine manufacturer. If they sell a bottomless portafilter for your machine, I recommend you to buy it from the folks that made your machine. But many times, buying from the manufacturer is not simple and many times they don't carry one. So the next best place is Amazon. Here are bottomless portafilters for some of the most popular espresso machines on the market:

54mm bottomless portafilter for breville barista express

A bottomless portafilter for the very popular espresso machines Breville. This is 54mm unit, compatible with Barista Express, Barista Pro, Barista Touch, Bambino Plus, Infuser, and Duo-Temp Pro.

58mm bottomless portafilter for e61 espresso machines

A 58mm naked portafilter for all espresso machines with an E61 brew group. It is compatible with the Flair 58, ECM, Rocket, Sanremo, Synesso, Slayer, VBM, etc… Made by Normcore, a reputable espresso accessories manufacturer.

gaggia classic pro naked portafilter

One of the most popular inexpensive espresso machines on the market, Classic Pro, is certainly going to need a bottomless portafilter. This is a 58mm OEM portafilter, Made in Italy.

58mm naked portafilter for breville bes920

58mm bottomless portafilter for the higher end Breville machines, including BES920XL , BES920CBXL , BES920BSXL , BES900XL, and the Oracle BES980XL.

51mm portafilter for delonghi ecp3420

This is a 51mm portafilter for cheaper DeLonghi espresso machines such as Delonghi ECP3420, EC155, BCO430, EC260.

51mm bottomless portafilter for delonghi dedica

A three ears 51mm bottomless portafilter for the DeLonghi Dedica EC680 and EC685. It has a double shot filter holder.

Conclusion

In conclusion, using a naked filter holder for bottomless extractions offers a direct feedback of the espresso extraction process. If you are committed to improving your espresso skills is one of the best espresso accessories to own. However, if you are buying it just because it looks cool, maybe you should reconsider.

While being able to view the shot flowing in a beautiful stream with tiger stripes is appealing, getting to pull a shot like that requires dedication and determination. A regular filter holder on the other hand is simpler to use, but you will never get perfect shots with it.

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