Posted Wed Jun 10, 2009, 3:09pm Subject: Technically and Mechanically - Conical vs Flat Burrs
Looking at grinders at various price points from $300 to $1000 I noticed some have conical burrs and some flat burrs. Refusing to believe that grind quality can be solely related to price, is there a fundamental reason to choose a flat over a conical burr grinder? Currently I’m just gathering information. I know everyone has an opinion of what’s best. I read them. They tell me to buy the Rocky or the SJ or the la Pavoni and I’ll be perfectly happy and I probably would be.
I just like to make an informed decision based on technology.
My question then is “technically” and “mechanically” why is it better.
Posted Wed Jun 10, 2009, 3:23pm Subject: Re: Technically and Mechanically - Conical vs Flat Burrs
Well, "better" is a value judgement.
One cannot generalize based on burr type alone. I have both flat burr grinders and conical burr grinders (multiples of each type). Each has their advantages and disadvantages. Which is "best" is subject to personal preferences.
The larger commercial grinders with conical burrs are very expensive, and tend to be high quality and well made. But if you're lucky enough to be in a position to choose between grinders that cost over $1k each then you will probably be very pleased with the performance (conical or flat burrs alike).
Posted Wed Jun 10, 2009, 5:43pm Subject: Re: Technically and Mechanically - Conical vs Flat Burrs
Let me start by saying I really do appreciate the comment...and I really liked the artical you attached on the 3 grind heads
With that said..
better is a value judgement is the very comment I'm trying to avoid. Of course Better is Better... and If I spent $1000 you can rest assured I would expect to be happy.
what I'm interested is an opinion based on real experience and first hand facts and data. You stated in your reply that you have both and "each has thier own advantages and disadvantages"
This was exactly what I am looking for. Given all things equal and assuming the 2 you have both are of at least "better" quality... Please tell me what the advantages and disadvantages of each have been in your experience. i.e. Does one type grind lightly roasted beans better? Is one type easier to clean? Does one type have a tendency to need it's burrs replaced more often ?
Jmanespresso Senior Member Joined: 18 Jan 2009 Posts: 2,151 Location: Westchester NY Expertise: I live coffee
Espresso: Alex Duetto II Grinder: Compak K10 - Vario Vac Pot: Yama-SY5/SY8/TCA5 Drip: V60, Beehouse, CCD Roaster: Hottop B
Posted Wed Jun 10, 2009, 6:20pm Subject: Re: Technically and Mechanically - Conical vs Flat Burrs
When it comes to large burr sets, BOTH stlyes do a good job.
Flavors in the cup change between conical and flat... Some people LIKE the taste from a conical, some dont. same with flat.
In general, bigger is better, but, you hit a point where it doesnt really get better persay, but different. Is a flat burr Mazzer Major better then a Mazzer kony? Well.. it may grind FASTER.. but the taste in cup will be no better or worse, just different.
I highly suggest you to make yourself a large cup of coffee, and sit and read the entire "Titan Grinder Project" Thread. You will have a much better perspective then. I used to think Large conicals were the best, and I was ready to sell my Major to get one... After reading that thread I have changed my mind. I will take my Mazzer Major to my grave, as well as adding a large conical to my setup.
Follow Your Bliss
Coffee makes your constantly overcome your prejudices and re-evaluate your own "received wisdoms" when it comes to judging cup flavors. -Tom Owen, SweetMarias
(IMO) I'd say that within certain price ranges the "better" grinders are comparable to each other independant of burr type. This is why I linked the Robur taste test, because I feel it illustrates that point. Bear in mind that the taster is a highly accomplished cupper who has a more sensitive palate than most of us mere mortals and you will see that the differences between the high-end grinders are slight.
In the picture you can see the three grinders on my espresso bar today. Two have large flat burrs and one has 68mm conical burrs. For most conditions, the quality of the shot when properly adjusted and groomed is comparable for all three. The factors that best differentiate these three grinders are not the burrs (but rather the adjustment mechanism, or the doser, or timer, or speed or noise, convenience, waste, etc.)
Here are some of the pros and cons (all based onmy personal preferences, yours may be different):
The big conical seems easier to dial in (it seems to have a larger sweet spot). Maybe it's a tad more forgiving because of the longer grind path of the big conical burrs, but I feel like that same grind path causes it to waste coffee when run with a full hopper because there are more grounds to clear out between sessions (it also grinds volume quickly so if you adjust while grinding you run through a bunch of beans). I load per shot and clear the path every time so there is virtually no waste. This Macap is also noisier than the Mazzer or the Mahlkoenig, but if I could keep only one it would probably be this one.
The Mahlkoenig k30 Vario is a serious piece of engineering work. It is easily the fastest and quietest grinder I've ever owned and it's comparable to the Robur-E in this regard. The doserless timer-based design makes it a very precise coffee dispenser and if I was to pick a grinder for higher volume or to serve a party it would be this one. It's engineered features make this grinder a breeze to use. The downside (for me) is that to use a timer for dosing you must keep beans in the hopper. As I just mentioned, I find this a wasteful practice because you must clear the grind path at the start of a session....BUT the advanatge of the flat burrs in this regard is that there is less coffee trapped in there so there is less waste.
The Mazzer Super Jolly is one of the "Gold Standard" commercial espresso grinders available today. The grind quality is excellent and it's fairly fast, and quiet too. Mazzer is well known for build quality and of the three commercial espresso grinders I have; this one is probably the heaviest even though the motor power rating is less than the others. Mazzer dosers have issues unmodified, but these are easily overcome with simple (quick and inexpensive) modifications.
I personally feel like the shot quality is indistinguishable between the Mahlkoenig and Super Jolly. Both have similar-sized flat burrs and whatever differences may exist are generally overshadowed by my inconsistency pulling shots.
As far as comparing my grinders for conical vs. flat burrs for your stated criteria (in my experience):
No difference in grinding light vs. dark beans
No difference in ease of cleaning the burr area due to burr type
No difference (that I know of) in terms of time between burr replacement. It would probably be more accurate to say that the conical burrs are more expensive but expected to last longer so the cost of ownership is probably a wash.
Taste profiles may differ slightly in that the big conical sometimes seems to help delineate better while the large flat burr grinders seem to make smoother/rounder shots. Of course this is very slight to my palate and very dependant on operator technique, most times it would be hard for me to tell the difference.
Of course, my grinders all retail in the "expected to be excellent" price range. I feel like the big conical is more forgiving for adjustment and it sure seems to make it easier to pull consistent shots, but this is NOT true for less expensive conical grinders I own (hand grinders, Baratza Virtuoso, and the LaPavoni PGC with Trespade burrs).
The less expensive conicals seem to offer more bang for the buck in terms of grind quality but they tend to be very loud and not as easy to dial in....the stepless adjustment is a must for me with these.
While you probably would be happy, do not confuse being "happy" with high quality. I've never seen anyone compare a Rocky and an SJ, and prefer the Rocky. Nor do I know anyone who recommends a grinder from Pavoni over an SJ . . .
My question then is “technically” and “mechanically” why is it better.
First of all, Chuck, define "better." This is not a trick request. What does "better" mean to you? How do you quantify it?
It's easy to define what constitutes a good grinder: one where ALL the particles are of a consistent size. In other words, it isn't just about how fine (or coarse) it will grind, but the even size of all the grinds. What you do not want is some individual grains the size of a grain of rice, while others are the size of table salt, and still others are like talc. You want them all the same size (or close to it.)
Both a conical and a flat design is capable of accomplishing this, but not every conical and/or burr set can do so. The biggest thing to remember is that with either a conical or flat set, bigger is better. That is, a 64mm FLAT burr set will be preferred over a 38mm conical every time -- or rather, I will prefer it. So, too, will I prefer a 64mm flat burr set over a 50mm flat burr set. And so on . . .
But among the grinders that feature a large conical v. large flat burr sets? The simple answer is either one does the job.
So, given that either burr set is capable of providing excellent results, we return to my initial questions: What does "better" mean to you? How do you quantify it?
I quantify it in the cup: is there a difference in taste? As others have already pointed out, some say that large conicals yield a more focused cup (sometimes described as "brighter"), while large flat burrs yield more rounded ("laid back") flavors in the cup. That said, I'm with Jon when he says
Of course this is very slight to my palate and very dependant on operator technique, most times it would be hard for me to tell the difference.
Indeed, rather than continuing to repeat variations on a theme, let me just point to Jon's posts in this thread and say "+1" . . .
OK, there's more to it than that (but not much more).
I used a Gaggia MDF (50mm flat burr set) for 20+ years, and thought it was great. Or, at least, I was quite happy with it. Then I got a Mazzer Mini (58 mm flat burrs). Now 8mm isn't much, and of course there is more to it than that, but the Mazzer significantly improved what was in the cup. Then, I got a La Cimbali Max Hybrid, and it blew the socks off the Mazzer Mini -- as I've said before, getting the Max Hybrid (with its combination conical and 64mm flat burr) was the single biggest improvement I've ever made to my espresso quality.
I still have the CMH, but I moved it to my office, and have a Mahlkönig K30 Vario*at home now. I love its quiet, its speed, its engineering, and I love the flavors in the cup . . .
* Note: the link here is to the K30ES, not to the K30 Vario. The ES is stepped; the Vario is stepless.
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