Dooglas Senior Member Joined: 12 Mar 2005 Posts: 690 Location: Portland, OR Expertise: I love coffee
Espresso: Expobar HX, La Pavoni lever Grinder: Ascaso, Baratza Drip: Bonavita, Bodum press Roaster: GeneCafe, Behmor
Posted Sat Jun 13, 2009, 12:51pm Subject: Re: Technically and Mechanically - Conical vs Flat Burrs
I don't think any grinder made primarily for home use will stand up to the commercial units discussed in this thread. Having said that, I have used an Ascaso I-1d for years and have been well satisfied with the result. It is an excellent choice at the price point you have budgeted (it will also fit in spaces that will not hold an SJ).
Posted Sat Jun 13, 2009, 10:26pm Subject: Re: Technically and Mechanically - Conical vs Flat Burrs
"gory details" are you kidding. Finally some real facts and data.
I guess I am somewhat amazed at the general similarity of the wet and dry curves and the percentage fo fine particals all starting to peak at the same time at about 9 microns. I could not open the plots on the Teme's link but reading the text it sounds the the data indicated a wider partical distribution with conical burr than flat burr.
Are all 4 of your grinders in your test flat burr? Surely with 4 different grinders, they cannot all have the same shape burr design, cutting angle, etc or speed and yet the curves are all so similar. Is this making the case for flat burrs?
Being a novice to espresso but a trained engineer in design of experiments... this was good stuff. I wonder how much data I can learn with a simple "finess of grind" gauge? I certainly cannot see the bi-modal distribution but is it fair to say, looking at the charts, that I should see little or no fine particals smaller than 8 micons or so?
Posted Sun Jun 14, 2009, 11:51am Subject: Re: Technically and Mechanically - Conical vs Flat Burrs
Were you surprised when you saw the data and 2 were from flat and 2 conical?
Should the curves be that close or, do I infer from the data, that the better coffee grinder manufacturers actually design the burrs, motors, etc to actually create these curves as the industry considers these partical distribution as the "benchmark curves" for a properly ground bean that the user and the average good quality espresso machine can extract the proper flavor the roaster expected?
If that is the case. I'm satisfied. I was not prepared to blindly spend a lot of money on a grinder just because someone once said "better is better" or "spend the most you can on a grinder"
It may be then I am correct...and please correct me if I'm not, that the more expensive grinders do a better job mainly because they threw sufficient R&D money at their design to insure the burr and machine could create a grind with this benchmark curve and the quality of the machine parts and tolerances, insure that it will duplicate this curve for years to come.
An enormous amount of research has been devoted to coffee-related topics, including grinding for espresso. It wouldn't surprise me if the better manufacturers discovered these advantageous burr setups and others followed suit (although I'm guessing the bimodal distribution we see in John Weiss' test was discovered as the outcome and was not the driving basis of design).
Posted Sun Jun 14, 2009, 9:48pm Subject: Re: Technically and Mechanically - Conical vs Flat Burrs
Digger, you might also consider the Baratza Vario. It's more compact, has a timer, and grinds as well as the big iron giants. closer to $400, but has practically no waste, is quiet, and will grind eveything from Turkish to French Press grind, as well as espresso. click here
Posted Mon Jun 15, 2009, 6:35pm Subject: Re: Technically and Mechanically - Conical vs Flat Burrs
My first grinder was priced in the $150. range and was a conical burr grinder and my second grinder was in the $500 to $600 range and was flat burr. Ofcourse the second grinder performed better then the first as was evident even on my $150. starter espresso machine I had at the time before my prosumer espresso machine arrived.
There are many other factors to consider besides flat or conical burrs and they are not all technical decisions .. will the thing fit in your kitchen ? Most home espresso makers grind one shot at a time .. if you buy a grinder big enough to grind all the espresso that your neighborhood requires for their morning rush hour commute will it still be practical for that 15 to 20 gram dose you add for that single morning shot ?
It's been a few years since I looked at grinders but at least three of the top prosumer / semi light commercial grinders at that time were all flat burr. This is not to say or make any claim that one is better then the other but it certainly is not a decisive factor for home espresso makers.
It will not wreck your espresso making experience if you buy one of the reviwed sturdy flat burr grinders in the $500 range and not that conical burr grinder.
good advice for wrong reason. The biggest innovation in grinders manufacturing has been "RETURN" to conical burrs, since all manual grinders were built with conicals (and all electric, professional and household, with flats). While flat burrs are perfectly capable of doing the job, there are a number of reasons why a manufacturer should go conical : first and most important on same size OD (outside diameter) and same number of rotations conical have a much lower peripheral speed = less heat generated, "softer" contact with the bean ... secondly much bigger grinding surface of conicals resulting in a much longer life (at least twice as much) and more consistent uniformity of grind, third more precise adjustement (more forgiving..) due to the conical insert of lower burr into upper burr when compared to the super precise alignement of upper and lower in flat burrs (sorry if this does not explain clear enough, but I am trying to say that with the same rotation of adjustement the variation is bigger in flat versus conical).... Noise I believe is strictly a matter of housing because when you "impact" a bean logics say that at higher speed you produce more noise, and this could mean that a conical is supposed to be quieter, and that does not always happen in real life, but you can always verify that by placing your noisy grinder into a cardboard box...... But then there are a number of industrial and commercial reasons that justify the actual market reality (last but not least the totally different opinions of users, as you can easily see from this very thread..). P.S. Bigger is not necessarily better ..........
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