Grinder burr seasoning? - Page 2

Grinders are one of the keys to exceptional espresso. Discuss them here.
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#11: Post by shadowfax »

John, that won't help, because neither of us would be able to do side-by-side, blind comparisons. You need to send me your Robur on loan so I can do the necessary testing. If I like your burrs better, I'll swap with you and send yours back with my burrs. :lol:
Nicholas Lundgaard


#12: Post by portamento »

shadowfax wrote:It sounds fishy, but on the other hand--I am a big fan of cast iron cookware, and I know firsthand that it takes a very, very long time to fully season a cast iron skillet. Persuading my wife to bake cake and cornbread in it definitely seemed to speed up the process on my favorite skillet, but it certainly improves only slowly for me. I would imagine if someone at a restaurant took it under their wing, it would be fully seasoned in a matter of weeks.
Have you tried removing your burrs and baking them into a few cornbread batches?

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#13: Post by shadowfax »

Hmm, that could be interesting... Maybe not cornbread, but coffee cake? eh? Who's got the guts to try that? Not me. :lol: I was just illustrating how long it can take to season metal with oil...
Nicholas Lundgaard

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gyro (original poster)

#14: Post by gyro (original poster) »

Hi guys, thanks for the responses. I figure I've only put through around 4lbs so far. Perhaps I used the wrong title for this thread... 'Grinder break in' may have been more appropriate. I have no doubt that the taste will improve, but I suspect the performance will improve over a longer time period as the burrs settle in a bit.

At present, the taste is a definite improvement over the Mini-E (with SJ burrs) I have been using. The main point of concern is the apparent inconsistency and 'relative' lack of speed. I'm doing a double in about 7.5secs, which is about half the speed what I expected and what the grinder was factory set at for a double timed dose.
From the video, the speed is apparent, but so is the fluffy grind. Looks a little different on mine to date...

HB wrote:But the Compak K10 WBC did arrive fresh from the factory and I noticed its grind setting drifted initially.
mivanitsky wrote:I have the Kony E. It has the impeller augur like the Robur E.

It improved greatly, in terms of ease of dialing-in and flavor, over its very real break-in period. This was mostly over by 8lbs through the grinder, but I noticed some change up to 12lbs.
another_jim wrote: did an initial test on the Compak, which arrived new, and was disappointed since it tasted slightly dull and burnt compared to the other Titans (which I got broken in). After about 5 pounds, it pulled even.
I am thinking perhaps the speed has something to do with the 'lumping'. The extractions even without WDT are still visually on par with the Mini-s WDT pours, but they are disconcerting to look at in the basket. I wonder if as the burrs get worn down a little to a more 'even' state if grinding speed increases and literally throws the coffee out the chute. At present it is slow, backs up, and gets forced out the chute once its clogged. At the end of the chute, the anti-static wire cuts it into nice little cubes that eventually break off and fall into the portafilter.

This may be masked a lot on a dosered grinder, as the lumps are broken up by the thwacking of the doser.

Do you think its possible that as the burrs wear that speed will increase. I am thinking along the lines of during manufacture, the burrs cannot possibly be all even. That must mean that during grinding, if a few are sitting proud, they must be doing the lion's share of the work. So instead of 420RPM, if only half the burrs are actually doing the business when brand new, perhaps I am getting more like and equivalent of half that. Just an idea that could explain it? or not...
RapidCoffee wrote:But I have replaced burrs on several commercial flat burr grinders, and never noticed any need to run vast quantities of beans through the burrs prior to use.
Me too, a difference between conicals and flat burrs? dunno... got me stumped.

I keep coming back to this though, from the current USBC, from coffeed...

"Having seen the first lbs through 3 or so new Robur Es, I can agree that they need seasoning. 150 to 200 sounds excessive but it certainly takes a bit. When ours first landed in our Chicago shops they were spiting out cubes... literally small cubes of coffee falling into the portafilter. The dosing was a bit inconsistent at this point as well. Now however (several hundreds of pounds later) they are working like magic, smooth, consistent and fast. However, even when they were spiting out cubes, we could still pull good shots, it was just really disconcerting.."

I suspect Nicholas may have it right
shadowfax wrote:it takes a few pounds to get them tasting right, but >100lbs to get them to stop clumping?
I think I'll pop down the road and see if I can find some cheap coffee to sacrifice, although 'cheap' and 'coffee' are two words you don't often find in the same sentence in HK. Mind you, neither is 'good' and 'coffee'...

Cheers, Chris

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Team HB

#15: Post by another_jim »

I keep wondering who's sillier; the grinder manufacturer's who keep converting grinders designed for dosers to doserless, or the people who keep buying them. Is there any grinder originally designed to operate with a doser that is better without one?
Jim Schulman

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#16: Post by shadowfax »

The thing that shocks me most about your comment (Chris) is that it takes 7.5 s to grind a double shot. I've used my own Robur and a friend's Robur E--both of them grind 14-17g of coffee (a good variety of coffees from light to dark roast) in about half the time you're getting. The Robur E I used is noticeably faster than my own Robur, which I attribute to the augur that's on it. On the other hand, I know John Weiss has said that his Robur is somewhat slower than mine... I really wonder what the deal is there.
Nicholas Lundgaard

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gyro (original poster)

#17: Post by gyro (original poster) »

another_jim wrote:I keep wondering who's sillier; the grinder manufacturer's who keep converting grinders designed for dosers to doserless, or the people who keep buying them
Thanks Jim. I love the doserless design on the Mini-E and from the look of the You Tube clip, the ROBUR E when running properly looks great. Each to their own I guess, plenty of threads on that one... I wonder how many people here use the doser version how it was designed for (ie full)?
shadowfax wrote:The thing that shocks me most about your comment (Chris) is that it takes 7.5 s to grind a double shot.
Yup, seems odd, given the factory setting was in the mid 3s range if I remember correctly before I had to change it. Just got another couple of pounds of stale beans, so will feed those through it. I would expect it to be slightly slower than the 110V versions, since on 50Hz it runs at 420 vs 500 RPM, but the video previously posted was 50Hz so its still off by a factor of 2.

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Team HB

#18: Post by RapidCoffee »

From page 1 of the TGP:
RapidCoffee wrote:Measurements of grinding speed and grinds retention:

Robur: ground 20.0g in 8-9 seconds, yielding 19.6g grinds
MXK: ground 20.0g in 20-22 seconds, yielding 19.2g grinds
Super Jolly: ground 20.0g in 10-11 seconds, yielding 20.0g grinds (using my doserless mod :) )
Robur and MXK were brand new, fresh out of the box. Different coffees, roasts, and especially grind settings will have an impact on grinding speed. But I'm getting similar results on my used Robur.

Conicals are not (typically) speed demons, due to their (typically) slower rpm. The flat burr Major (or SJ with duranium burrs) beats the Robur in grinding speed. But for home use, who cares?

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gyro (original poster)

#19: Post by gyro (original poster) »

Thanks John. Interesting to note that there may be quite a variance between grinders of the same make and model. As for speed, I hope to use the grinder in a cafe in around 2-3 years (after a career change), but the difference of 3 or 4 seconds is unlikely to be of real significance. It was just my thought that the grinding speed may have been affecting the exit velocity, which in turn has caused the lumps...

I found a fairly inexpensive 1kg bag down the road, so thats been through. Just dumped a kg out of the roaster as well of old SM greens that are way past their best before date. That will give me some freshly roasted stuff to play around with before I move back onto the nice tasting stuff.

Cheers, Chris

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#20: Post by dsc »

Hi guys,

I've got a Major which was converted to doserless using the funnel approach and I couldn't be more happy with it. Yes the grinds are pushed through the grid, but I have no clumping problems what so ever, so I'm a bit surprised that you are getting some.
another_jim wrote:I keep wondering who's sillier; the grinder manufacturer's who keep converting grinders designed for dosers to doserless, or the people who keep buying them
I can't really agree with you here Jim, I think the funnel works very well, even though it leaves some coffee stuck in the grinder 'throat'. Besides what else is there on the market that offers doserless grinding without the need to weigh the beans everytime you make a shot? K30, the new Elektra grinder, anything else?

Strange thing about the grinding times, although the Robur is 3 times slower than the Major (and I doubt that conicals grind 3 times faster than flat burrs).