Getting Naked: Making My Portafilter Bottomless

Robert McKeon Aloe
Geek Culture
Published in
6 min readFeb 6, 2020

Two years ago, I got my first bottomless portafilter for my Kim Express. I was aiming to get a better insight into how to improve my shot, but I didn’t realize I would see an immediate improvement. My skill didn’t change immediately, only the obstacles between the coffee and the cup changed. Recently, I decided to go bottomless on my Pavoni and my Enrico of Italy, and that decision requires some word to cut the bottoms off.

The Naked Advantage

There are four main advantages to a bottomless portafilter:

  1. Nothing between the coffee and the cup (other than the filter).
  2. Ability to watch and adjust shot live.
  3. Ability to video and review later for further failure analysis.
  4. No need to clean a portafilter on a regular basis.

I didn’t anticipate the first advantage, but it made a big difference. I have since used a regular portafilter for the same shot, same basket, and it reduces the mouthfeel and complexity of a shot. That small residue that builds over time on the portafilter is key to the cup.

Failure analysis has been key for me to improve my shot by allowing me to see where my shot preparation or shot technique went wrong. It has helped make sure if the shot isn’t level, not distributed well, or the levels of my staccato shot are not dialed in. Videotaping also takes away some stress of having to be so focused on viewing the shot looking for the key detail. Additionally, I use the video to recording pre-infusion, bloom, and infusion timings, which allows me to focus more on the shot.

Recording the shot for me has become as vital as recording data for the shot.

Finally, I don’t like to clean. I’ve only more recently been regularly cleaning the piston head of my main machine. So going bottomless certainly helped.

Too Many Machines

My mother-in-law gave me an old Pavoni in the basement, and I bought an Enrico of Italy from an old guy on a boat in South San Francisco. Both machines work well, la Pavoni a bit better, but I knew they had even more potential. So I decided to go bottomless.

The beauty of an espresso machine is the resulting coffee, not the machine.

At first, there was resistance. My mother-in-law and brother-in-law were insistent that I not do it. They said it would ruin the beauty of the machine. To me, I don’t care so much for the astetic of the machine; the beauty of an espresso machine to me is the espresso it produces. However, I had a spare portafilter, so game on without hurt feelings!

Buying a bottomless for la Pavoni was a possibility, but it was more money than I’d like to spend. I saw online that some people used a drill, drilled multiple holes, and eventually they got to the bottom coming off. I bought a drill bit, tried, and quickly failed. I didn’t have a drill press, but even still, the drill bit was not going to be easy.

I posted my struggles to la Pavoni group on Facebook, and someone suggested a diamond tipped bit. It was $10 and seemed like it would do the trick in a few minutes with a drill press.

I also decided I could use this on the Enrico of Italy. The trick with that portafilter was that I didn’t have an original basket. I found a 63mm basket, and I had to have part of the top lip trimmed down. Then a friend suggested adding a plastic piece to help it stay in the portafilter. It turns out that this drill piece was just the right size for the bottom of the filter. The trick was to make sure the hole was centered.

Drill Baby! Drill!

I borrowed a friend’s drill press, and once I got everything setup, la Pavoni took a few minutes. I was nervous I think because the Enrico went faster.

La Pavoni

Enrico of Italy

After a little sanding

Taking a Shot, Naked

La Pavoni is at my in-laws house, so I have to wait a few more months to use it, but I was able to use the Enrico of Italy soon after. The bottom of that portafilter looked a little wild, but I left it because I thought it looked cool. The two pieces sticking out don’t serve a function, but I didn’t want to risk grinding them down and causing an issue with how the filter sits in the portafilter because parts for the Enrico are scarce.

First Shot

The first shot looked uneven, and I wasn’t sure if the filter sat in the portafilter unevenly. So I pulled another shot and rotated the filter basket.

Second Shot

The second shot came out almost the same, and I started to suspect the machine wasn’t sitting level because during the pre-infusion, everything came out pretty evenly. So I check with a level, and there was a big tilt on the table.

Not only did I benefit from the coffee not touching the portafilter, I discovered a machine setup issue that I’m not sure I would have run across otherwise.

I now am able to better understand the intricacies of the Enrico considering that almost nobody regularly uses the machine, so document on best techniques is scarce. One might claim it is just another manual, but it’s functionality seems to be in-between a spring driven lever and a manual lever in my experience. The Enrico is spring driven, but it doesn’t react the same like the Kim Express.

I dreamed of getting some naked portafilters for these machines, and I only have three machines that don’t have a naked portafilter but could in theory: la Peppina, la Moka, and la Brikka. I know the possibility la Moka and la Brikka are slim considering nobody has done a moka style before, but la Peppina seems doable with custom hardware because that handle is so weird.

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Robert McKeon Aloe
Geek Culture

I’m in love with my Wife, my Kids, Espresso, Data Science, tomatoes, cooking, engineering, talking, family, Paris, and Italy, not necessarily in that order.