Burrs in grinders for coffee come in 2 types: conical and flat.
Conical Burrs
- Doesn’t require as much energy to work, so are used in both manual and electric grinders
- Produce a bimodal distribution of grounds (grinds at the selected size as well as a bunch of fines or very small grounds)
- Adds more body for espresso. Smaller conical burrs also work for filter coffee, but larger burrs (e.g, 83 mm) produce less clear filters
- More suitable for use in medium to dark roasted espresso
Flat Burrs
- Requires more energy to operate, only found in electric grinders
- Most people prefer flat burrs, more commonly found than conical burr sets in titan level grinders
- Produces a more unimodal distribution of grounds, easier to align than conical burrs as they only need to be parallel
- Produces espresso with less texture but more clarity for fruit notes in light roasts, can pull high extraction yield shots
- More clarity in filter coffee, better than conical for filter due to generating less fines
Differences Between 98MM Flat SSP Burrs
This is what SSP says about the 98MM burrs they have available:
- 98MM high uniformity (HU): Single Dosing espresso, Clean cup, intensity, has a similar taste profile to the 64 MM unimodal multipurpose burrs
- 98MM low uniformity (LU): Espresso, brewing, bulk grinding, more complexity, Lower grinding temperature, used to be the default burr set in monolith flat max until the switch to Shuriken burrs.
- 98MM ultra-low fines: only suitable for brews (although I’ve heard some people having success with espresso but I’d imagine it’ll be harder to pull shots)
- 98MM brew burrs: these are very new, there’s a thread on the HB forums discussing these new brew burrs
While deciding on which burr set to get for the Lagom P100, this is the response I got from someone on the Espresso Aficionados Discord:
I think the question of “what burrs should I get?” is essentially unanswerable.
The question really comes down to a small portion related to the types of beans you like to work with and a larger part of the type of shots you want to pull.
Many folks prefer pulling faster 1:3 shots on 98mm HU, but I like HU for light roasted espresso pulled tight at 1:1.5 or less.
I prefer thick and juicy fruit bomb shots and for me, HU extracts enough of lighter roasts early in the pull to get me a high TDS and flavors that I prefer over longer shots that will be lower strength, but higher overall extraction.
I choose to balance extraction with brew temperature, rather than yield. If a shot is sour, I will pull it hotter, not longer. I only go longer when the tastes turn bad at hotter temps and it is clear that I need more yield to hit the sweet spot. But again, this is all meaningless unless you’ve sat down and had espresso with me and tasted what I make and said “yeah, I like that” or “nope, I want something different in the cup”. Since I make espresso tailored to my tastes, my preferences are rather a moot point to everyone else…
LU is great, but for me, I like the punchy character that I get with HU more than the softer flavors I tend to get with LU. Both will dial in just fine and make very similar beverages, but HU will have a higher TDS at a given ratio and thus mouthfeel and -to a lesser extent- body are increased.
LU shots need to be shorter to match the mouthfeel of HU and since they are less aggressive on extraction, they require a slightly higher ratio to balance out the highs and the lows, which reduces strength and is just less appealing to my palate.
Others will have different preferences, but we are splitting hairs here. Really fine hairs.
For milk drinks, in not sure it much matters…
Think about it this way:
I pull short shots because I like the sensation of drinking them and the flavors pop.
In milk, if you extract more and have a less punchy shot as the base, you make up for that by adding less milk if the final beverage size stays the same.
So your option is less coffee and more milk with the tight shot or more coffee and less milk with the longer shot.
Seems to me the longer shot will cut through milk more than the short shot because it is equivalent to a larger dose of coffee in a fixed volume shot. I mean if you leave the basic recipe alone and just increase the yield, you are adding solids to a fixed-size final beverage.
And here’s another thread on comparative differences between the burrs:
Based on second-hand experience and looking at the geometries and reading SSP’s descriptions this is my best guess:
- ULF is the one that gives you a semi-traditional espresso shot. Low outfall = more fines. But at brew range, it delivers the most clarity and the less fines. Will excel at 1:2.2.
- HU has the most fines at spro range, it will extract fast and short. Good if you want high ey at 1:2.2.
- LU is the one that has the less fines at espresso range due to the high outfall. It will extract slower and need a slightly higher ratio to reach balance. Good if you want high ey at 1:3 and mid ey at 1.2.2.
- 98 Brew is like LU but on steroids, higher outfall, even less fines.
LU is generally seen as better for brew than HU and more forgiving of coffee flaws but more demanding on puck prep.
HU is the ultimate in clarity and has more fines so less demanding on puck prep.
Then there is the new SSP Brew which like the name suggests really is for brew not espresso
Based on this, I decided on the LU burrs.