As the poster who brought up refractometers, I'd like to point out that the only interest I have in measuring my Monolith Flat versus my K10 is to investigate the claims that, everything else being equal, large flat burr grinders produce a higher %EY than large conical burr grinders.

This is not to say that a higher %EY means the espresso will taste better. It might in some cases, such as very light roasts, but in other cases it won't.

I rarely use my refractometer when dialing in. The only time I do is to get an idea of where in the %EY spectrum an extraction lies when I'm having trouble dialing in a difficult-to-extract light roast. Otherwise, I mostly use it for experimentation, testing, comparisons and troubleshooting.

I would love to see a simple, valid comparison of %EY between the two. That would be easy - just get both dialed in a pull shots with equal parameters. A mean of 5 from each grinder would be enough to tell if there are consistent differences.

My understanding, however, is that one would probably be pulling shots of different types of beans with the different grinders - isn't that the supposed benefit of having both? In that case the brew parameters would differ anyway?

peacecup wrote:My understanding, however, is that one would probably be pulling shots of different types of beans with the different grinders - isn't that the supposed benefit of having both? In that case the brew parameters would differ anyway?

In actual usage yes highly likely different beans pulled different grinder. In a taste comparison no same beans all grinders each comparison flight or it wouldn't be a comparison.

There is value in attempting to achieve the highest EY possible for each grinder. Not at a specific EBF - but the highest EY possible. A better aligned/sharper burred grinder will always enable one to go higher.

Logically speaking - while it may taste awful for the specific blend tested - having the *option* to go finer opens up more possibilities...

Peppersass wrote:As the poster who brought up refractometers, I'd like to point out that the only interest I have in measuring my Monolith Flat versus my K10 is to investigate the claims that, everything else being equal, large flat burr grinders produce a higher %EY than large conical burr grinders.

This is not to say that a higher %EY means the espresso will taste better. It might in some cases, such as very light roasts, but in other cases it won't.

I rarely use my refractometer when dialing in. The only time I do is to get an idea of where in the %EY spectrum an extraction lies when I'm having trouble dialing in a difficult-to-extract light roast. Otherwise, I mostly use it for experimentation, testing, comparisons and troubleshooting.

Dick, I know this is old, but that was me. Ever get around to this? Are you ditching the K10 for good?

I'm in the fence.

RyanJE wrote:Dick, I know this is old, but that was me. Ever get around to this? Are you ditching the K10 for good?

I'm in the fence.

I did some espresso extraction yield comparisons between the Monolith Flat and the K10 when the Flat first arrived. I did five tests with four different coffees, one dark roast, one medium roast and two very light roasts. In all of the tests, the Flat extracted an average of about 0.1% more than the K10 (all in the in 20%-21% range). For all intents, that's within the margin of error and therefore identical.

This doesn't surprise me: both are high-quality grinders with large burrs. I didn't expect the Flat to produce significantly higher %EY than the K10 just because it has flat burrs. The higher extraction yields reported for the EK-43, for example, may be due to very large burrs designed for bulk/brew grinding being used for espresso. The Mythos burrs in the Monolith Flat are designed for espresso grinding (though I hear they do a very good job for brew grinding too -- haven't tested that yet.)

Caveat: The Flat was brand new when I did the tests and the burrs weren't fully broken in yet. I still need to run about 5-6 more lbs through it to get there. But I don't expect an earth-shattering difference in %EY.

The difference in taste is pretty subtle (I'm not a supertaster), but I slightly (and I mean slightly) prefer the Flat with light roasts. Again, that's with the Flat burrs not yet broken in.

The big difference between the grinders is the workflow: no comparison, even with my K10 being modified for single-dosing.

I'll hang on to the K10 until the Flat is broken in and will repeat the tests. Then some lucky buyer is going to get one of the best grinders ever made for a very good price.

Dick - did you try also at slow speed for the Monolith (same dial in)?

Peppersass wrote:I did some espresso extraction yield comparisons between the Monolith Flat and the K10 when the Flat first arrived. I did five tests with four different coffees, one dark roast, one medium roast and two very light roasts. In all of the tests, the Flat extracted an average of about 0.1% more than the K10 (all in the in 20%-21% range). For all intents, that's within the margin of error and therefore identical.

This doesn't surprise me: both are high-quality grinders with large burrs. I didn't expect the Flat to produce significantly higher %EY than the K10 just because it has flat burrs. The higher extraction yields reported for the EK-43, for example, may be due to very large burrs designed for bulk/brew grinding being used for espresso. The Mythos burrs in the Monolith Flat are designed for espresso grinding (though I hear they do a very good job for brew grinding too -- haven't tested that yet.)

Caveat: The Flat was brand new when I did the tests and the burrs weren't fully broken in yet. I still need to run about 5-6 more lbs through it to get there. But I don't expect an earth-shattering difference in %EY.

The difference in taste is pretty subtle (I'm not a supertaster), but I slightly (and I mean slightly) prefer the Flat with light roasts. Again, that's with the Flat burrs not yet broken in.

The big difference between the grinders is the workflow: no comparison, even with my K10 being modified for single-dosing.

I'll hang on to the K10 until the Flat is broken in and will repeat the tests. Then some lucky buyer is going to get one of the best grinders ever made for a very good price.

Great feedback! Main point of interest to me is that the taste was close even though maybe not broken in. I can see how workflow would improve.

What type of beans / roasts do you typically use at what doses? I like my 15g VST for lighter roasts and the compak is the only grinder I've used that doesn't cause clumping that isn't fixed very well by WDT. I still have to WDT light roast low dose tho for even pulls.

PLEASE let us know your thoughts on brew grinding if you ever try it out. Id love an AP grinder but can't fit an EK or R-line Compak under my cabinets!

Checking my notes, I used five coffees, not four, for comparing the Monolith Flat with the K10:

Cafe Lusso Gran Miscella Carmo - A much darker blend than I typically buy, but quite tasty. This was supplied by Kafatek with the Monolith Flat.

Temple Coffee Dharma Blend - One of my go-to coffees from one of my go-to roasters. I'd call it a medium roast, perhaps slightly toward the medium-light range.

Compass Ethiopia Idido Yirgacheffe - A light roast SO.

Terroir Borboya Ethiopia Espresso - A very light roast.

Terroir La Soledad Guatemala Espresso - A very light roast.

My take on the roast level is based on eyeballing the color, measuring it with a Tonino, and long experience with these roasters.

All of these coffees extracted 20%-21% on both grinders when run Normale. Nonetheless, there was still plenty of acidity in the light roasts.

bumping this back from the dead. Would love to see this single dosing showdown.