98mm Burrs for Brew

Grinders are one of the keys to exceptional espresso. Discuss them here.

#1: Post by gritts »

Hi all,

After having a few DM conversations with members (like zero610 and Jake_G), I thought it would be a good idea to pool the opinions of all HB brew-focused users.

I'm interested in uncovering what 98mm burrs are optimal for filter brewing only, promoting sweetness and clarity in the cup at a 1:15 to 1:18 ratio with extraction yields from 19-26%.

Currently I have SSP Low Uniformity and SSP High Uniformity burrs in 98mm (the latter of which need to be seasoned and installed), paired with a Monolith MAX at 250rpm. I've heard from a variety of sources that these burrs are "no good for filter," but I haven't heard too many reasons why. I'd love for this thread to open up meaningful discussion on these options. For example, with my SSP LU burrs, after three weeks, I notice a fair amount of clarity and acidity at all grind sizes (hitting 21-26% EYs), but the sweetness seems to top out prematurely in comparison to my Baratza Forté BG.

I'll follow up on my findings with the HU burrs. For the time being, I'd love to hear any conclusions or suspicion from other users on their 98mm brew experiences (with these or other burrs).


#2: Post by zero610 »

I'm no expert but from other posts I've read, your experience with the LU and HU burrs coincides with others - more on the side of narrow taste profiles. I feel like LU and HU burrs are the good choice for espresso and occasional brew. Jack of all trades but master of none; however, much more on the side of good espresso than good brew.

Purely opinion based, any variant of a cast burr seems to be the best if you're brew focused. The problem lies in just how many variants there are and whether there are real differences in taste to the common coffee drinker. Possible options are pre/post 2015 EK burrs, SSP's cast variant (both with the SSP modification and the clone of the pre-2015 EK burr). Also, coatings MIGHT play a part, albeit smaller than geometry. Uncoated, DLC, ZrN, etc. I believe that coating effects are mostly a function of how much friction is being generated from the grinding process.

I'd also love to hear other opinions and anyone with solid info! Thanks for starting this Gritts.

gritts (original poster)

#3: Post by gritts (original poster) »

Here's a small comparison video that I made between the High Uniformity and Low Uniformity burrs. The geometry of the HU seems to be more slanted, with shorter finishing teeth. Also, another detail which is hard to tell from the video, I believe the finishing grooves (between the teeth) of the LU burrs are inset further into the metal.


#4: Post by rmongiovi »

I'm really not clear what SSP is saying about its 98mm burrs. From the espressotool website:

1. Uniformity (aggressive) - High > Ultra Low > Low = > Cast burr

2. Amount of fine at brewing range - High > Low = cast burr > Ultra Low

3. Grinding Temperature - High Uniformity > Low = Ultra Low > Cast burr

And it also says that their cast 98mm has "more uniformity than original burr set with more complexity of your coffee."

How is ultra low greater in uniformity than low? I thought "uniformity" was built into the name.
How is cast at the bottom of uniformity but in the middle of amount of fines? (I'm presuming that "greater than" in bullet 2 means fewer fines, which is confusing all by itself.)

I really wish he'd just publish particle size distribution plots.


#5: Post by franklin270h »

A bit late reply but if looking for an additional opinion here are mine from using a few sets. Keep in mind, I use an EK43S, in which the difference in RPM may affect experiences with each burr comparative to the monolith.

I've used: Mahlkonig newer coffee burr (came with grinder), A reground set that was converted to the old (pre-2015) geometry, SSP Ultra Low, SSP Low for filter. I've tried plenty of coffee from the SSP highs before in a friend's grinder, but not my own personal use as filter is my use case.

The high uniformity is definitely not a great filter burr, though it is a great espresso burr. It functions more like a turkish burr, and those super flat teeth combined with the EK's larger burr size (compared to say 80mm) seems to make them even more espresso specific because of the longer cutting path. You can make decent brews with them, but you'll have an experience where the coffee kinda 'just tastes like coffee'-generic and sweet but not very interesting.

I found the Ultra lows to be a pretty awful filter burr. I used Ditting 804 burrs in a Bunn and thought I would get a similar cup profile with some extra advantages, but I didn't. The SSP Ultra lows comparatively have *much* more shallow finishing teeth than the Ditting design they are mimicking and I feel like that's what made all the difference- they had a fairly uniform grind but made a ton of mud and fines at filter grind settings and didn't have a lot of extraction potential. They actually made more fines than pretty much every other 98mm burr I've used. Perhaps he's tweaked the grind since then, I got mine in 2019, but I'd stay away from them tbh.

The SSP Low is their better machined burr for filter use in my opinion. I find they're capable of a pretty good cup and my experience with them is similar to your impressions- they highlight clarity and acidity but lose out a little on the depth and sweetness compared to some others. I also find they do better at finer grind settings (say v60) than coarser. Almost all of the SSP burrs seem to fall apart the coarser you get.

I'd call the MK old design cast burrs by far the best filter option, they blow all the others out of the water. The MK New cast burrs vs SSP LU is more of a wash. Every other one I've tried is markedly worse for filter coffee. I don't necessarily think it's "because they're cast" as much as it's because all of SSP's options were designed with being multipurpose in mind. Even the LUs.


#6: Post by Ejquin »

Great info. To be clear - the reground burrs are not the same as the SSP version of the cast pre-2015 EK burrs, correct? I have a grinder for filter on the way with the SSP version of those burrs and can't wait to try them, though some have reported there may be very small differences between the SSP version and the actual pre-2015 burrs.


#7: Post by franklin270h »

Yeah there's a difference between the ssp cast burr and the MK original. Mostly the angle of the middle section, he made his flatter (less dramatic angle from the center of the burr to the outside edge) for more uniformity (espresso potential).

He has a post on his Instagram some time ago where he showed the differences.


#8: Post by Ejquin »

Thanks. The verdict seems to be that the SSP version is still a very good brew burr. I'm assuming it would still be a better option than the others for pure filter. Anyhow, I should have it in my hands soon to try out.


#9: Post by zero610 »

From emails with Hansung at SSP, he can also make a copy of the original pre-2015 EK burrs. I'm guessing there would be minor differences between those and an original pre-2015 EK set but, again, just a guess and a close as you can get without finding an original EK burr set. Not sure if he'll charge more for those either, since they're "off menu." Good questions for him though - he's good about responding to emails.


#10: Post by franklin270h » replying to zero610 »

Hard to say, because I'd seen an Instagram discussion on that topic and he ended up sending them his new cast design and they were a little miffed about it.

For a copy of the original, he'd need the original to make a mold with. Perhaps he has one now, or can get one.

From a handful of discussions with people and observing, the difference with the old brew burr and the newer cast burrs and SSP's burrs is the final angle on the finishing section.

The old brew burr has a very slight angle, so theres a bit more of a "taper" from the inside to outside edge. That's what makes grinding it take longer (machine time) because you have to cut deeper into the cast teeth. That taper allows particles to more gradually be shaped to final size. The newer ones are more flat, which gives potential for a tiny bit more uniformity at the expense of fines.

Probably also what makes the old brew burr great at brew and more frustrating at espresso.