The spout of a regular portafilter sure makes it look like your espresso is coming out in a nice neat stream, doesn’t it? It gives you the impression that everything inside the basket is as it should be. How nice. Isn’t coffee wonderful and easy? La la la.


Once you take the bottom off your portafilter you may discover that it’s an absolute shambles in there. Coffee may shoot every which way and land anywhere but in your cup. I’m sorry to report it’s not the naked portafilter that’s letting you down – you have some homework to do.

A common misconception about the bottomless, or naked, portafilter is that it will instantaneously make your coffee better. I have news for you:

  • The bottomless portafilter won’t magic you some better coffee. Abracadabra! Nope.
  • You will probably make a mess. This is true of all naked portafilters, not only ours.
  • You may embarrass yourself in front of your friends
  • You may cry out in anguish and frustration
  • You may seek to take your frustrations out on me or the team here at EU
  • Just when you think you’ve figured it out, you change to a different coffee and all hell breaks loose again

The Skinny

With some homework and practice you will conquer the beast with no bottom. Here’s where to start your naked journey. Ponder these points:

The Mess

Your coffee is all over the shop. Your shots come out in multiple streams with lots of dripping, in and out of your cup, possibly even down the portafilter handle. Until recently, I made more of these than anything when using the naked portafilter. In truth, I almost gave up.

Possible causes:

  • Ground the coffee too coarse
  • Too much coffee in the basket
  • Coffee was clumped, poorly distributed or tamped unevenly

The Gusher

Shot gushes out quickly with little resistance. Resulting coffee is watery, weak and lacks crema.

Possible causes:

  • Coffee is far too coarse
  • Not enough coffee in the basket
  • Not tamped hard enough

The Hernia

You may strain so hard that you pop an eye out and still you hardly get any coffee to come through. I still occasionally experience this.

Possible causes:

  • Coffee is ground too fine
  • Too much coffee in the basket
  • Tamped too hard
  • Coffee is roasted darker than your usual. Dark roasts seem to benefit from a slightly coarser grind.

Of course this is grossly simplified and there’s many other subtle points to consider, but if you’re anything like me you’re probably bored by now and keen to go and tackle your newly acquired bottomless portafilter. If it ends in tears, come back and read the rest of this post. I’ll be here waiting.

Some time later

Oh, you’re back. How did it go? … Well I’m sure the cat will come back when it gets hungry. Do you need a hug? There there. Shall we continue?

One thing at a time

As with any experiment it’s better to change only one thing for each test. Try a grind adjustment but not both grind and dose in the same test. If you change two things and get a better shot, or a worse one, how will you know which change was the cause?

Here’s a video of me dialing in our espresso blend using the naked portafilter. In three attempts I change one thing at a time. First I reduced the dose, then increased the coarseness of the grind. I promise I’m having fun in the video and didn’t remove the audio because of the f-bombs. 😉

Grind for the cup

There’s little joy to be had in pre-ground coffee. Buying pre-ground coffee only to get home and find it’s either too coarse or too fine will end in tears. Invest in a burr grinder and grind only enough coffee for each cup.


You want your coffee to be fairly evenly distributed in the basket before you tamp. This helps reduce variations in coffee density, causing dead spots and channeling (cracks and fast spots). Tamping on a clumpy, peaked mound of coffee will likely lead to a dead spot in the middle of the basket.

I use the straight back of a knife or a business card to distribute and level off the coffee before I tamp. Depending on how fancy your pants are, you may even want to pull the trigger on some of Scottie Callaghan’s dosing tools.

If your coffee seems to be clumping, use needle to stir the coffee in the basket and break up the clumps. This is the kind of activity that results in jeers and sneers from non-believers. It also results in better coffee. Who’s laughing now, you instant coffee guzzling jerks?! That’s right. Me! AHAHAHAHAHA!

Still with me? You’re a real stayer. Let’s plow on.

Now Press

It’s not a race, but you should try to press the levers fairly quickly to build the pressure sooner. Taking too long to press will cause the water to find only the easiest path through the coffee. This can result in the coffee only extracting and channeling around the outside of the basket. I tend to press the levers firmly almost all of the way down and then slowly as the first drops of coffee appear. I want to see the extraction cover all of the basket fairly quickly.

Don’t play it again, Sam

Press the levers only once! Contrary to the misinformation from supposedly reputable sources (ooh snarky!), pressing the levers twice will disturb the coffee in your basket and almost certainly cause channeling.

Dark versus Light Roasts

I’m no scientist but my observations have concluded that at the same grind setting, shots from lighter roasted coffee run faster than with darker roasts. Don’t be surprised if you get great shots from one coffee then switch to a dark roast and give yourself a hernia. I’m serious, no word of a lie, just last week I pulled a back muscle pressing a shot.

In truth, you’re likely going to need to tweak things whenever you get a new coffee.

Have Fun!

Enjoy yourself! Give yourself time to experiment and don’t be discouraged if things get frustrating. There’s as much to be learned from your mistakes as from your victories.

If you’re ready to take the plunge, you can pick up a naked portafilter from all of our online shops. These fit both the ROK and Presso espresso makers.

New Zealand:
USA / International: