Curious what a bottomless portafilter actually is and why so many baristas use one? This special portafilter shows exactly how your espresso flows and helps you improve your technique.
In this blog, we’ll explain what a naked portafilter is, what its benefits are, and how to use it.
What is a bottomless portafilter?
A naked portafilter is a portafilter without a bottom. When you look underneath it while pulling an espresso shot, you can see the filter basket directly, which is where the espresso flows out of the machine.
Having a clear view of the extraction is valuable because it lets you see exactly how evenly the coffee flows and immediately spot any mistakes.
Plus, a bottomless portafilter doesn’t have a spout in which coffee residue builds up, making it easier to keep clean.
Benefits of a bottomless portafilter
A good extraction equals a delicious, balanced espresso. When an espresso is out of balance, you can taste it, but with a naked portafilter, you can also see it happening.
A naked portafilter has no bottom, allowing you to look directly at the underside of the filter basket. If your tamping is uneven, you’ll immediately notice that the espresso doesn’t flow evenly from the basket.
If there are clumps in your ground coffee, the water can’t pass through evenly. It will follow the path of least resistance, creating small tunnels in the puck, a phenomenon known as channeling. This prevents the full range of aromas from being extracted, resulting in an unbalanced espresso.
A naked portafilter makes it much easier to spot what’s going wrong during extraction, so you can fix it. With a regular portafilter that has a bottom and spouts, you wouldn’t be able to see this.
How to use a bottomless portafilter
You use a naked portafilter the same way you would use a regular one:
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Click the included filter basket into the naked portafilter.
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Use a dosing ring to get all the ground coffee neatly into the basket.
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Break up any clumps with a WDT tool and use a coffee distributor to create an even surface.
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Place your naked portafilter on a tamper mat to protect your work surface.
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Tamp the coffee evenly by applying firm, consistent pressure once.
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Insert the bottomless portafilter into the group head.
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Keep in mind that the espresso might splatter when you start the machine.
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Observe the extraction carefully.
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Adjust your grind size or dose if needed for your next espresso.
Bottomless portafilter tips & tricks
Stir the ground coffee before pulling your espresso shot. By breaking up any clumps, the water can flow evenly through the coffee, improving your extraction.
Use a coffee distributor to create a flat surface, which you can then tamp evenly with a tamper.
Use a tamper mat for stable tamping, this helps the water flow evenly and reduces splattering.
If your espresso still splatters when using a naked portafilter, make your grind a bit finer. This increases resistance and helps the espresso flow in a smooth, consistent stream from the basket.
Always use freshly roasted beans, that’s the key to great extraction. Check out our selection of specialty coffee beans to get started.
Frequent problems when using a bottomless portafilter
My espresso is splattering everywhere
Splattering usually indicates that the water is flowing unevenly and with too much pressure through the coffee puck. When that happens, it’s time to go back to the basics. The tips below can help you fix it:
Are your ratios correct?
A good starting point for a double espresso is 18–19 grams in, 25 seconds extraction time, and 40 grams out.
Did you distribute and tamp the coffee properly?
If the grounds aren’t evenly distributed, the water will form channels through the puck, creating high-pressure spots that cause splattering. This step is crucial.
You can use a coffee distributor or simply tap the portafilter gently with your palm to start. Then tamp with firm, level pressure so the water flows evenly through the puck.
How fresh are your beans?
Freshly roasted beans (ideally roasted within the last two months) tend to slow down the flow and improve both extraction and flavor.
How fine is your grind?
If the water runs through too quickly, grind your coffee a bit finer to create more resistance.
My shot runs too fast (or too slow)
This is another common problem. Even when you’ve distributed and tamped correctly, your shot might still flow too fast, for example, reaching 40 grams in just 15 seconds. This usually results in a weak, sour espresso.
If your coffee tastes sour, your extraction is likely too fast. Try grinding finer to achieve a longer, more balanced extraction time.
If your extraction takes too long, grind slightly coarser instead.
I have channeling on one side of the portafilter
This issue can be tricky to spot. Sometimes, one side of the portafilter shows a smooth extraction, while the other side doesn’t.
Recording your shot can help you identify this problem since it’s often less obvious than splattering. You might notice bubbles or foam forming on one side of the basket.
This usually happens when the puck separates from the wall of the basket.For example, if you accidentally tap the side with your tamper after tamping.
Make sure to tamp once, firmly and evenly, to prevent channeling as much as possible. It’s a small detail, but it can make a big difference in your espresso.
Cleaning your bottomless portafilter
A naked portafilter requires very little cleaning because there’s no bottom where coffee residues can build up. In a regular portafilter with a base and spouts, coffee often gets trapped inside.
If you remove the filter basket from a traditional portafilter after some time, you’ll usually find the inside covered in black coffee residue. To clean it properly, the stainless steel parts need to be soaked.
Cleaning a naked portafilter is much simpler: just rinse it with water. You can also use a brown barista cloth if you’re pulling multiple shots in a row.
Keep in mind that the black and wooden handles of naked portafilters should not be left soaking in water. And never put your naked portafilter in the dishwasher, it can’t handle that.
