Simplifying Coffee Distribution for Espresso

MacGyver Espresso Tools

Published in

The Startup

12 min readOct 4, 2020

When I started with a lever machine, I did a simple finger distribution. I didn’t pay much attention to shot distribution, but over time, I discovered seemingly minor differences in shot distribution can lead to major channeling problem during extraction. However, I haven’t been satisfied with what is available commercially for distributors, so I started to use whatever was around the house, resulting in some MacGyver distributors.

Also, I’m aware the title is paradoxical in that I’ve aimed to simplify the idea of coffee distributors to something I could make at home, and I’m able to easily modify them. However, the result is that I’ve made a few tools to use during my puck preparation, and as a result, I’ve complicated the process of distributing coffee even though I have simplified the tools.

The Start

Three years ago, I bought an OCD style distributor as well as a leveler. I used both for a long time. When I discovered layered shots, I had to make due with whatever was available because I had to distribute the fine layer at the bottom of the basket and nothing else existed.

I will also note that OCD style tampers actually reduce extraction yield. They mostly affect the top of the puck, and I have yet to see data to show they are valuable aside from the aesthetics during coffee prep.

The key attributes of a MacGyver distributor are that they are cheap, easy to make, and the work well enough.

The Toothpick

I started with a toothpick as I had started to do the WDT method to improve my shot. It was okay, and it was very portable, but I had some issues getting to the edge of the basket.

The Bent Paper Clip

I moved to the bent paper clip as a way to get to the edge of the basket, and it had the added bonus of breaking up clumps.

As a result of pulling quite a few shots on the Flair, I got used to the idea of holding the paper clip still and rotating the basket. So I took the springs out of all my bottomless portafilters for my other espresso machine.

No basket clip to hold a ridged filter basket

The Uneven Paper Clip

While examining multiple shots, I discovered I had a donut problem during extraction. Even for shots that typically would look good, pressure pulsing revealed they were not as good as I would have liked. I found multiple contributing factors to these donuts:

The water entered the piston on the sides resulting in side channeling.
The tamper doesn’t go to the sides, further contributing to side channeling.
A flat puck distribution didn’t help these issues.

So I made a paper clip that pushed more coffee to the side of the basket. After tamping, the side of the puck would have a higher density, slowing the flow a little relative to the center.

However, this arrangement proved difficult because the paper clip wasn’t easy to hold, and coffee would go over the top. So it didn’t completely eliminate the problem.

The Plastic Cutout

I moved to a cut out of plastic to solve the issues of the uneven paper clip, and I went through a few versions to make sure I got the right pitch angle for the sides. In this case, I used the hard plastic top from the top of a can of anchovies. I go through one can every two months, so I had plenty of materials for multiple iterations.

This really improved my shots, and it allowed me to focus solely on tamping as it allowed me to have a consistent shot to shot distribution.

This plastic distributor has been easy to reproduce for other basket sizes.

The bottom of a staccato tamped shot you show the effect of the distributor after tamping and pulling the shot.

The Cross Plastic Distributor

I decided to add another flat piece to make a cross to help the distributor stay balanced as I spun the basket.

Don’t Touch the Bottom

One issue with the previous plastic distributors was that they touched the bottom and shots were prone to having some unevenness in the middle to one side or the other as I pulled the distributor up, so I made another one to test and wasn’t able to touch the bottom.

However, the pitch on the cuts was slightly higher than before, which oddly caused donuting, so another modification was necessary.

The Improved Design to Not Touch the Bottom

I made the top of the distributor sit on the filter basket rim. This helped especially with a higher handle.

The Top Distributor with Ears

One of the issues of this distributor is that the higher you raise it, the less it can stay centered. So I made a separate one for the top half of a staccato tamped shot, but I included ears to help the filter stay centered.

The Bottom Distributor with Ears

The ears worked so well, I made a bottom distributor in the same fashion. This is quite difficult because the tolerance needs to be tight enough to stay centered but not so much that the filter can’t spin.

The Top Cleaner

Ears help coffee from going outside of the basket, but the coffee ends up on the top edge of the filter, which is also not ideal. So I made a finishing tool that sits on the edge to help push coffee on the lip of the filter back into the filter.

Adjustments

The bottom distributor was causing some issues leaving a dark ring in the puck, which indicates coffee wasn’t flowing well from there. I looked at it further and determined a slight adjustment was necessary.

So I made the flat part larger so that the center area, where density will be lower, will be larger.

This adjustment eliminated the ring and my extraction went from 20% EY to 23%.

The New Top Cleaner

For the top cleaner, it worked well but pushed coffee off of the side of the basket.

So I made an adjustment with the aim to push grounds on the filter lip into the basket.

Then after some testing, I changed the ears for the top cleaner because the previous adjustment only reduced the mess being made. I then added support to keep the basket more stable while spinning inside the cleaner.

This worked well:

Adjusting the Leveler

I use a leveler on the top, but it doesn’t quite go to the edge. I thought that was contributing to side channeling so I put a paper filter between the leveler and the coffee just during the tamp. Since the paper filter is larger than the filter, it pushes down the coffee on the sides.

This did reduce side channeling, but now there was some blockage in a ring.

Left: before using paper filter with leveler; Right: after using paper filter with leveler

This ring issue was very obvious looking at the bottom of the puck as well as an observed drop in extraction yield.

The dark ring about a third of the way from the side to the center

This problem occurs just at the point where the density starts going up because of the way the distributor pushes grounds to the side. So I made a very small cut to slighting increase the density in the center of the puck to help even this out.

Left: previous iteration and puck donut; Right: the slightly modified bottom distributor.

What amazes me is that such a small change could have such a big difference. Extraction yield went from 20% on the left to 24% on the right in a similar ratio shot.

Minor Adjustments to Reduce Mess

I added some bumpers on my scale to help the filter spin in one spot. This reduced grounds coming off of the sides, helped improve my consistency, and reduced the time to prepare each layer because the distributor stayed steadily in place.

The Overcomplicated, Simple Distribution End-to-End

Bottom distribution of two layers:

Top distribution of two more layers:

Tamping with paper filter aid:

The shot:

Post-shot puck bottom:

There is still room for improvement, but then again, I’m more and more doubtful of the existence of a God Shot. Rather, there’s always a better shot, and you may never know when you’ve had the best you’ll ever have.

There are many costly solutions for distribution, and while they effectiveness is not always fully known, the MacGyver distribution type of tool lends itself to a higher bang for your buck. At the very least, being willing to try to make your own gives you the ability to handle espresso issues while traveling.

If you like, follow me on Twitter and YouTube where I post videos of espresso shots on different machines and espresso related stuff. You can also find me on LinkedIn.