Hopperless grinders and the affects of burr speed / type

Grinders are one of the keys to exceptional espresso. Discuss them here.
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tekomino

#1: Post by tekomino »

We know that conical burr grinder are not nearly as sensitive to column weight as flat burr grinders. Many of us single dose K-10 with fantastic results. Then you have Pharos hand-grinder which uses also those 68mm conical burrs and people report very good results with it. I have small 38mm conical burr Rosco Mini hand-grinder and it is working really, really nicely for espresso.

So evidence is on conical burrs being insensitive to column weight.

On another hand I do have first hand experience with Major, Vario etc. flat burr grinders and they are sensitive to column weight. You can single dose Major but you need weight on top of the beans. This works very well in my experience. But, yes, column weight is critical for flat burr grinders.

Interesting to note, Versalab which is hybrid conical/flat burr grinder works just fine as single dosing grinder.


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RapidCoffee
Team HB

#2: Post by RapidCoffee »

tekomino wrote:We know that conical burr grinder are not nearly as sensitive to column weight as flat burr grinders.
The grind size on my Robur is very sensitive to bean weight in the hopper - more sensitive, in fact, than any other factor (e.g., different beans or roast age). I never compared this to a flat burr grinder; I'm not even sure how to measure it. So... any data to back up your assertion?
tekomino wrote:Interesting to note, Versalab which is hybrid conical/flat burr grinder works just fine as single dosing grinder.
Well, one could argue that you are effectively single dosing the flat burr set on the Versalab. The conical burr set breaks the beans into chunks, which then feed into the flat burrs for grinding to espresso size. I imagine the double burr set helps with single dosing.
John

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tekomino

#3: Post by tekomino »

RapidCoffee wrote:So... any data to back up your assertion?
Don't know what kind of data you are looking for, but you try, you see, its simple like that :D Get Major and give it a try...

By sensitive I mean that you can use it for single dosing and without weight on the beans successfully. I and many here can single dose K-10 with great results without column weight. Single dosing Mazzer Major without weight on beans does not give consistent or even acceptable results to me. Vario was the same, its simply much more consistent with beans in hopper than when single dosed.

The question was:
bgn wrote:After using several different mazzer grinders, and currently using a Major E, I'm not sure i would trust any burrs to grind consistently that weren't loaded with the weight of a hopper full of beans. As Peacecup said earlier, you're working against the original design of their intended use.
So my answer is conical burrs, like ones used by the grinder which is subject of this thread, can give consistent results when single dosed which you do on hand grinder. People with Pharos also report same.
RapidCoffee wrote:Well, one could argue that you are effectively single dosing the flat burr set on the Versalab. The conical burr set breaks the beans into chunks, which then feed into the flat burrs for grinding to espresso size. I imagine the double burr set helps with single dosing.
I don't see Mazzer Major and Versalab behaving the same. Major must have weight on beans to grind consistently, M3 does not. Difference is that there are conical burrs crushing beans in Versalab before passing them onto the flat burrs and Versalab runs at slower speed...
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another_jim
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#4: Post by another_jim »

Rapidcoffee wrote:The grind size on my Robur is very sensitive to bean weight in the hopper - more sensitive, in fact, than any other factor (e.g., different beans or roast age). I never compared this to a flat burr grinder; I'm not even sure how to measure it. So... any data to back up your assertion?
For those of you new to the dosing wars: This has been an interminable argument. Here are the facts:
  • People who single dose, find the big conicals to be both more consistent than other grinders and completely satisfactory for their use
  • People who do not single dose, find that even with the big conicals, single dosing is not as consistent as using a hopper.
  • People who single dose use lots of different coffees every day and week; they are interested in getting each one good enough as quickly as possible. People who use hoppers, use one coffee for a long stretch, and try to get it eventually perfect.
  • I suspect this difference in intent and in the dialing in process has something to do with why we judge these grinders differently
Jim Schulman

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RapidCoffee
Team HB

#5: Post by RapidCoffee »

The assertion that "we know" it's OK to single dose conical but not flat burr grinders took me by surprise. I have single dosed flat burr grinders (including a Mazzer Major) many times, with perfectly acceptable results. The flow rate increases significantly as the bean load decreases, just as it does with conical burr grinders. But I never tried to compare them.

I have no interest in reopening the debate about single dosing, nor in derailing this thread. It's obvious that the slow rotational speed of a hand grinder changes matters.
John

Grant

#6: Post by Grant »

I agree. While I have no direct experience with large conical burrs, my "common sense" gene tells me that a hand-driven burr (ie being driven at very low rotational speeds) may have some different grinding characteristics than a motor driven burr.

It is conceivable to me that until the grinder is available for testing, that lumping (sorry...bad pun) it into the same characteristically similar area as a motor driven burr set of the same size may be premature.
Grant

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drgary
Team HB

#7: Post by drgary »

The only people who have these (added for clarity: HG One grinders) and have tested them are the makers. Maybe one of them can chime in. If they were experiencing inconsistent grinds I doubt they would be going into production. Similarly with the Pharos Doug and Barb did lots of testing to see if the grind quality really is good and consistent before their product announcement. Yes, there were tune-ups and such later to a grinder that was designed for mods. But we now are hundreds of Pharos into that journey.
Gary
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bgn

#8: Post by bgn »

I also have no desire go to with a single dosing question, but the prospect of using a hand grinder is interesting to me because I'm a person who rarely switches coffee and prefer a hopper. But grinders like the hg one don't have the option of using a hopper. Whatever, I'm looking forward to hearing more about this one.

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LaDan

#9: Post by LaDan »

RapidCoffee wrote:The assertion that "we know" it's OK to single dose conical but not flat burr grinders took me by surprise. I have single dosed flat burr grinders (including a Mazzer Major) many times, with perfectly acceptable results. The flow rate increases significantly as the bean load decreases, just as it does with conical burr grinders. But I never tried to compare them.
You are correct that for the same grind setting even the K10 will have a much faster flow when comparing single dosing to hopper load. I found that I need to set it about 5 marks finer if I want to single dose, and have about 2" of beans above the chute opening in the hopper to have an almost similar flow of a half full hopper.

The big question is, for example, if a single dose on "5" or hopper load on "10" give the same flow speed. Which cup will taste better? Sure, they both make very nice cups, but I always wonder if the hopper would be able to get you that next level of nicer flavors.

What I have serious doubts of, and I have no way of testing it, is that that particle size distribution, that bimodal distribution graph will look the same for both. I have a feeling that it will look a lot different between the same flows, the #5 and #10, for single dosing and hopper dosing. This SHOULD have an affect on the taste. But I am not capable of testing so many espressos in one session to make out the differences. My intuitive feeling is that hopper dosing will give me better cup. But wasting coffee, due to purging etc when I drink only about 2-3 drinks a day makes that not a good practice for me with the current crazy bean prices.

Somebody with access should make two graphs, one for a single dose, and one for half full hopper. I don't remember ever seeing such a comparison that is so important to us home-baristas. Then we can start discussing if one has flavor benefits over the other.

I'm sure the HG One will give very good cup with the Robur burrs in hand grinding RPM. But to jump to the conclusion that it will have the same flavor potential as in a Robur with a half full hopper is premature and my bet is on the Robur and its hopper.

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tekomino

#10: Post by tekomino »

LaDan wrote:But to jump to the conclusion that it will have the same flavor potential as in a Robur with a half full hopper is premature and my bet is on the Robur and its hopper.
As is jumping to a conclusion that:

1. There is difference in flavor

2. That hopper full of beans results in better flavor than single dosing

:wink:
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