Why do bulk grinders produce a superior grind for non espresso preparation? - Page 2

Coffee preparation techniques besides espresso like pourover.
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another_jim
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#11: Post by another_jim »

It's very cool, but it would be nice to have the axes labelled. Presumably the graph is for volume, not count or area. The particle sizes are shifted right from the TGP graphs, which is to be expected, since the grind is for brewing. But the Y axis is a mystery. The graph runs from 0.2 to 2.1, and that is not commensurate with the 2 to 15% levels shown on the TGP. For that matter, the numbers are not a distribution since the area under the graph doesn't sum to 100; nor are they a count, since they are decimals. It would be nice to know what the data means, how it was obtained.
Jim Schulman

earlgrey_44
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#12: Post by earlgrey_44 »

another_jim wrote: the Y axis is a mystery
Agreed. "distribution density" expressed as a decimal is a little too arcane for me. So, the exact relationship to TGP data is unclear.

Relative differences between the various Ditting charts remain meaningful, though.
Trust your taste. Don't trust your perception.

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Ben Z.
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#13: Post by Ben Z. »

another_jim wrote:The Grindmaster burr looks like an abrasion system with pegs, and I can't see this being much use for specialty coffee.
That's what my hobart looks like and it works really well. The motor it's attached to weighs about the same as 2 majors...

spaz2
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#14: Post by spaz2 »

Dave,

This is an especially well timed thread. I'm ready to learn whatever I can about drip coffee preparation. I have a Hario V60 and have made a few attempts at grinding for drip with the Mazzer mini B.
In reading some past postings on CG I see where an interest in filtering out the fines an espresso grinder produces has been a subject which has been introduced but perhaps fizzled out after a short discussion about using sieves to eliminate a percentage of fines produced by various grinders.

The grinders you mention do present an opening for an entrepreneur who can shrink one of those huge grinders into a chihuahua sized unit for home use. Perhaps there is a way to convert our less used grinders into a grinder for drip. Anyway I look forward to what ideas come from this ever inventive group. :)

Tom

Nick
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#15: Post by Nick »

Howdy. Infrequent visitor to H-B. :P

I've been asking other coffee professionals for a few months, "Have you ever brewed filter (drip) coffee ground on an espresso grinder?" So far: nobody. Needless to say, I'm looking forward to this thread develop.

One thought: So far, folks in this thread seem to be comparing what they know about espresso grinder burrs and particle size variation/distribution to bulk grinder burrs and their results. Keep in mind, what we know about espresso grinders applies to the effective range of grind size for espresso. Widen the gap between the burrs to a filter coffee particle size, and we're talking about a whole new grinding dynamic.

So here's a quick rundown of what I know of filter coffee brewing as it relates to grinding. My prior experience (before 2009) was brewing on a Fetco Extractor CBS-2052 1.5-gallon double brewer. Since then, I've been brewing a lot on pretty much every manual coffee brewing device there is. Siphon, V60, Chemex, Abid Clever... everything but an Aeropress (no real reason why).

I haven't done empirical study (using my ExtactMojo or otherwise), because there are too many variables for numbers to have relevance. The two results that have had the most relevance for me are taste and the amount of time that drawdown takes on an Abid Clever dripper. Drawdown-time might sound like an unusual thing to pay attention to, but I think it's very relevant; I dial-in the grinder to provide the right-tasting filter coffee beverage with 3m 30s as my target brew completion time. Sometimes, that drawdown is the last 30 seconds of the brew. Sometimes it takes 60 seconds (or a bit more). Would seem to correspond with quantity of fines to me, though "fines" in this context are probably different than for espresso.

Here's what I've had experience with, in some sort of chronological order.

Mahlkonig Guatemala: became the reference grinder for us. Hard to explain, but the Fetco brews had outstanding overall flavor with this grinder. No experience using this on any other brewer. Vertical burrs. Lots of static.

Bunn G-series bulk grinders: inexpensive, but my baristas complained that the flavors were less intense than with the Mahlkonig. Vertical burrs. Less static than the Mahlkonig. Manual brewing also resulted in very good, but not top-notch flavor potential.

Ditting 1203: the biggest 110V, I think. Baristas were as happy as they were with the Mahlkonig. Great clarity of flavor. Horizontal burr set. As much static as the Mahlkonig. Abid Clever drawdown took a full 60 seconds.

Ditting 804: kid brother to the 1203. Compared favorably to the 1203, though took a bit longer to grind (naturally). Abid Clever drawdown takes the same time as the 1203. Horizontal burrs.

Baratza Virtuoso: About the same brew flavor quality as the Bunn. Much slower (obviously). Interestingly, drawdown on the Abid Clever takes only about 30 seconds.

Baratza Vario: I've been using one, but I don't have enough experience with it to give feedback yet. So far so good though.

That's it for now. Again, really interested to see this thread develop, and one of these days, I'm gonna brew coffee ground on my Mazzer Kony or Super Jolly. Hope there are enough folks here with enough time away from espresso to brew, taste, think, and discuss filter coffee!
Nick
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earlgrey_44
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#16: Post by earlgrey_44 »

This and the related threads linked above have given me some insight into what I can and cannot expect a good espresso grinder to do, and made me more aware of the design differences between burrs.

There's plenty of good info about the effectiveness of less expensive espresso grinders compared with the upper crust, and where the entry level points are. Not so much for other brew methods.

I do hope we can see more careful taste experiences shared to help identify the benefits of a specialized drip/press grinder, especially how inexpensive and compact ones compare to the high end. (Even though this may be a bit OT for this site.)
Trust your taste. Don't trust your perception.

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cannonfodder (original poster)
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#17: Post by cannonfodder (original poster) »

I picked up a second hand BUNN LPG dirt cheap on ebay earlier this week. It arrived yesterday. I did a complete tear down to clean it up. They cleaned the machine, inside and out, with citrus cleaner. The machine smells like rancid orange coffee. I was hoping to get away with not needing new burrs, the the mold on the burrs has prompted me to order a new set. That and the ones in the grinder were dull as a hammer. I took a bunch of photos and will post a rebuild thread in the near future.

Solid yet simple grinder. Took me all of an hour to pull it completely apart, and I mean completely. I even took the motor core out of the housing so I could soak everything is Joe-Glo. Looks new now and the orange cleaner smell is no more.

A warning to anyone thinking of getting one. As with espresso grinders, new burrs are a good idea. These guys regularly go for 250'ish used. Burrs are 200. A new grinder is around 500. So you could purchase a new one for what a used with new burrs goes for. I gave under a 100 for it, I was not willing to go any higher knowing that. I have been bidding on them for months, finally snagged one for a reasonable price.
Dave Stephens

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another_jim
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#18: Post by another_jim »

As with all Ebay ventures, patience and a willingness to do some restoration is what gets the big savings.

The burrs and motor on the LPG are the same as on the G1,2, & 3. So once Dave and I have put the grinder through its paces, HBers will know how useful it is for home brewing.
Jim Schulman

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cannonfodder (original poster)
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#19: Post by cannonfodder (original poster) »

The motor is rated at 1800 rpm no load, 1400 at load, and it is DC so if you wanted to play with slowing it down, you could just add a pot and dial down the voltage provided it still had enough torque to turn under load. I bet turning down the burr speed would reduce popcorning with low doses.

I have the added benefit of having a BUNN plumbed in commercial drip pot. I have it tuned to brew half pots of coffee. The funnel holder on the grinder is made to hold the bunn filter cones so you can grind directly into the brew cone and avoid any stray grinds mess. I also have a plastic filter cone coming. I have plans on hole sawing a 1 inch opening in it to make a purpose built slide in funnel for things like press pot grinding.

My burrs will not be in until next week, then I can get it put back together and try it out.
Dave Stephens

spaz2
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#20: Post by spaz2 »

Dave,

I was tempted to purchase one of the used Bunn grinders on ebay but I've held off thinking that it would end up costing too much if I had to buy and install new burrs. It appears from your experience that my caution was warranted. The ones I was looking at were $266. shipped.

Does reducing the rpm normally work to greatly reduce popcorning in flat burr grinders? My Mini B popcorns like crazy and the Nino conical at 600 rpms popcorns much less, but needs an over the throat stopper to empty out all the beans in any reasonable time.

If you haven't already discovered this source here is a place to buy teflon sheets in various thickness in small quantities. Perhaps for use in a funnel or chute.. http://www.eplastics.com/Plastic/PTFE_S ... agodi1w3TQ

Can't wait to see how this project progresses. :D

Tom