Hello,

Our shop has a 2015 EK that I have modified to grind finer for espresso. I sanded the carrier and chamber and used the Mahlkonig Alignment tool. The marker test shows removal all around for both the carrier burr and chamber burr.

We have been using the EK to pull decaf shots at a recipe of 18/36 in 28 seconds at a grind size of around 1.2-1.4. Our batch brew extracts at about 22% at an appropriate grind size.


Today, I tried to use the EK to pull our single origins, but have had constant side channeling issues. Nothing about my technique has changed. I am using a WDT tool and tamping with a Pullman Big Step Palm Tamper. Grind is about 1.5-1.7. Recipe is 18 in, 36 out.

Has anyone had success with EK espresso shots and can provide any tips? If needed I can post a video later.

Also: this isn't happening with our other grinders (Mythos and E65s)

Do you remember if you have the "A" casting or "B" casting of the burrs? The letter is cast into the back of the burrs. (The castings were changed from A to B right around 2015.)

If you have the "A" casting, then pulling espresso can be challenging and may not be possible with light roasts. The "B" casting was modified specifically to be able to better handle espresso. However, many feel that the no-longer-available "A" casting produces superior pourovers and batch brews than the "B" casting.

(I have the "B" casting reground by SSP to the "A" casting profile. I can't pull espresso without going through contortions, and even then I'm at 1:4+ brew ratios.)

I can check later this weekend.

If I do need to upgrade the burrset, which SSP burr set would be worth getting?

First, just a reminder that any espresso-capable burr will compromise pourover and batch brew qualities in some way, and vice versa. There are quite a few people who think that the Mahlkoenig's "A" burr is the 'best' brew burr available, although the more extreme, in terms of clarity, "SSP Brew" burr has its proponents.

For espresso, the current darling in 98mm is the SSP High-Uniformity (HU). However, this is a burr that seems to work best with light roasts - think Sey Coffee in Brooklyn, or Friedhats or Manhattan in the Netherlands. The burr has a reputation for revealing and arguably emphasizing every defect in the coffee, whether in the green or from roasting (some would say especially roasting). I'm not sure that I would use such a burr in a shop over a more forgiving burr - although you do have the Mythos (85mm?) for that.

I just checked and it's the "B" Burr



So maybe it's an alignment issue? I'm about to take it apart and use a dial indicator to double check

NYFilter93 wrote:I just checked and it's the "B" Burr

So maybe it's an alignment issue? I'm about to take it apart and use a dial indicator to double check

Okay, so much for my hypothesis .

I realize these may not be practical solutions, but I would try:
- WDT; and if that doesn't change things, then
- cut up a filter paper in a round to fit at the bottom of the basket - probably easiest to wet the paper a bit when putting it on the bottom of the basket. Then dose, WDT, tamp, and pull. (The pull will be faster, but that can be addressed afterwards by adjusting the grind finer.)
If either of these work, then it may well not be alignment.

Good luck, and my apologies for sending you on a wrong direction.

All good! I'm glad I found out which type of burrs we have.

I'll also take a video of the puck prep later in the week

"Side" channeling?

Curious how that's detected: visible holes around the top perimeter of the puck, no flow observed from the interior disk of the basket, odd-looking stripes? Or am I misinterpreting what 'side' means?

I like the suggestion of putting filter paper at the bottom of the basket, and it could be instructive to examine the pattern on the paper after the shot. Channels show up as dark spots, and uneven extraction shows up as a color gradient.

Okay I'm pretty sure it's technique related. I just pulled a shot with no side channeling. Also by side channeling I mean liquid flowing from the outer edge of a basket. The shot I just pulled had no side channeling at all,