HomeRoast Digest


Topic: The life of burrs (13 msgs / 327 lines)
1) From: Kit Anderson
How long should a set of burrs last? My Kitchenaid set is looking pretty 
worn after a little more than a year, about 9 pots a week.
Kit

2) From: Tom Ulmer
Hello Kit-
I'm not sure which unit you're discussing. The ProLine says something about
600-800 pounds as the expected life expectancy.http://www.kitchenaid.com/assets/pdfs/product/ZUSECARE/KPCG100.pdf

3) From: Kit Anderson
Hi Tom,
I read that too. I do have the Proline. Something must be wrong. That 
amount of coffee should last me years. Either the alloy is soft, I have 
been making powdered coffee without knowing it, my beans are wicked 
hard, or there are a lot of rocks in my beans.
Kit
Tom Ulmer wrote:
<Snip>

4) From: mIke mcKoffee
That really sounds like an exaggerated life expectancy claim by Kitchenaid.
The Mazzer Mini burr replacement suggested at 300kg for average hardness
beans, 400kg for Jolly 500kg for Major. That's putting the Proline burrs
equal life of at the minimum the MM, I highly doubt it! Suggested
replacement for Rocky is 100# IIRC. From experience I know yearly highly
beneficial for Rocky, noticed a big improvement when I replaced after
1.5yrs, then went to yearly.
Kona Konnaisseur miKe mcKoffee
URL to Rosto mods, FrankenFormer, some recipes etc:http://mdmint.home.comcast.net/coffee/Rosto_mod.htmUltimately the quest for Koffee Nirvana is a solitary path. To know I must
first not know. And in knowing know I know not. Each Personal enlightenment
found exploring the many divergent foot steps of Those who have gone before.http://www.mdm.livingfreeandclear.com<Snip>

5) From: Aaron
the burrs will mostlikely show signs of 'use' as any mechanical device, 
especially one that will at times have metal on metal will do.
But the burrs themselves should be hardened steel and should last a 
lifetime really.
Someone mentioned 800 pounds of coffee...  again.  LONG time.
if yours is running into problems at a year,, something is not right there
aaron

6) From: raymanowen
Kit- the burrs amount to cutting tools, just like a straight cut flat
("Bastard") file.
A new file feels quite sharp as you slide your finger against it in one
direction- the cutting direction.
In the opposite direction, it won't cut and the feel to your finger will be
completely different.
Here's my suggestion: Purchase a spare set of burrs for your grinder, since
you will use them at some time. From time to time, A-B compare the feel of
the burrs to your finger.
In your grinder, I believe the burrs are two identical discs that cut nicel=
y
when facing each other, so you can just take out the easy one and compare
its feel to a new one. They both wear at the same rate.
Also, inspect the grind appearance. If the fresh grounds look like the fur
on the floor aftter a cat fight, s* can the burrs. Coffee grounds like that
will way overextract the fine fuzzy surface by the time the main body of th=
e
chunks extracts the way you want.
Blade mills do the same, although the sharp tips on my Grindmaster mills
seem to compensate for the weed whacker action.
By the way, Mahlkoenig makes what some people call the R2D2 grinder. I call
it the MOAG or BUFF, even though it looks kinda' neat. With the standard
three phase motor, it's pretty powerful and will grind a pound in under 15
seconds. At a Turkish setting, it takes about 15 seconds for a pound.
Did I say- their burrs are razor sharp and Mahlkoenig can actually resharpe=
n
them. For Three Big, it should have a V-6 and antilock brakes.
Cheers -RayO, aka Opa!
--
"When the theme hits the bass, I dance the Jig!" - -Virgil Fox at the Might=
y
Wichita WurliTzer

7) From: mIke mcKoffee
I respectfully disagree. Burrs use cutting edges. Just like the finest ice
hardened steel chef knife they become dull over time with use. Difference
being fine knives can be sharpened. Burrs as a rule you replace.
Kona Konnaisseur miKe mcKoffee
URL to Rosto mods, FrankenFormer, some recipes etc:http://mdmint.home.comcast.net/coffee/Rosto_mod.htmUltimately the quest for Koffee Nirvana is a solitary path. To know I must
first not know. And in knowing know I know not. Each Personal enlightenment
found exploring the many divergent foot steps of Those who have gone before.http://www.mdm.livingfreeandclear.com<Snip>

8) From: Aaron
you have a good point mike.
But are we supposed to grind with the burrs actually 'grinding' against 
each other then, or just 'almost' touching?
Doesn't zass claim, or used to that the burrs will last the life of the 
grinder... yeah I know that's kind of an oxymoron, (hopefully that is 
not offensive to oxygen breathing morons)   but still, yes you are 
correct they WILL wear out with metal to metal contact however shouldn't 
it last a bit longer than 100 pounds?
Many times, a good cleaning can do wonders as well.  What people might 
think is 'dull' and non cutting burrs is just so much crap impacted into 
them that those sharp edges you mentioned can no longer do their job.
Before running to replace the burrs, one might want to try to give them 
a real good cleaning.  Take them out, hot water, a tooth brush and a 
real good scrubbing.
I recently did that to my handheld zass and while it was not misbehaving 
before, and i did make efforts to keep it clean...ish...... the 
difference in it's performance was remarkable.
Perhaps they are using cheaper metals but a case hardened steel or high 
c content steel should last a while if properly taken care of.
either way though, unless there is a LOT of grinding going on there, 
normal wear and tear not withstanding, if they are wearing out in a 
year, .. something is wrong.
Aaron

9) From: mIke mcKoffee
Again I disagree that burrs wearing out in a year or so means something is
wrong. Actually time is totally irrelevant, poundage of beans through the
grinder is what counts. The act of shaving/cutting the roasted bean itself
is what normally dulls the burrs cutting edge, not metal to metal contact.
Though of course if the cutting edges of the burrs making contact to metal
that would of course dull them faster. 
Cheaper grinders like the Kitchenaid first in question I'd not be surprised
at all if grind quality noticably less in under 100# usage. I can guarantee
that a better grinder like a Rocky will exhibit noticle difference in grind
100# of beans through the burrs versus new burrs. Bean there done that
twice. Though a high quality grinder like a Mazzer with somewhat dull burrs
will still produce better quality grinds than a brand new cheap burr
grinder. So it's somewhat relative to what's expected.
Any "lifetime" guarantee on burr life is meaningless and unrealistic for
steel burrs. I highly suspect Henckels Pro S ice hardened steel blade knives
have a harder cutting edge than most grinders and yet do dull in normal use.
Not fast, but they do.
Agreed important to keep grinder clean, both for quality of grind AND to
keep stale grinds and coffee oils out of the brew!
Kona Konnaisseur miKe mcKoffee
URL to Rosto mods, FrankenFormer, some recipes etc:http://mdmint.home.comcast.net/coffee/Rosto_mod.htmUltimately the quest for Koffee Nirvana is a solitary path. To know I must
first not know. And in knowing know I know not. Each Personal enlightenment
found exploring the many divergent foot steps of Those who have gone before.http://www.mdm.livingfreeandclear.com<Snip>

10) From: tom ulmer
Why would you doubt that? Do you have some insight you are not sharing?

11) From: miKe mcKoffee
Actually oops, my bad, apologies to the List and KitchenAid. I was thinking
of the KitchenAid Classic not Pro Line grinder. Since the Pro Line's burrs
are about the same size as the Mazzer Mini's, KitchenAid's stated projected
"end of burr life" of 600 to 800 pounds not out of line, about the same as
stated for the MM (300kg).
How far grind quality will have deteriorated along the way prior to "end of
life" is subject to debate and personal persnickitiness. Is the grind
quality optimal than suddenly sub standard? Of course not, it'll very
gradually deteriorate over time. For instance which is why I and others have
found Rocky's burrs benefit from replacement 75-100# usage range. I don't
recall Rocky's actual stated "burr life" but IRRC that is less than the
stated "life expectancy". 
Kona Konnaisseur miKe mcKoffee
URL to Rosto mods, FrankenFormer, some recipeshttp://mdmint.home.comcast.net/coffee/Rosto_mod.htmUltimately the quest for Koffee Nirvana is a solitary path. To know I must
first not know. And in knowing know I know not. Each Personal enlightenment
found exploring the many divergent foot steps of Those who have gone before.http://mdm.LivingFreeAndClear.com<Snip>

12) From: Kit Anderson
Update on the Kitchenaid burrs-
I received the replacement burrs and compared them to the existing. What 
I thought was wear was the flattened area towards the outside. I assumed 
the 'teeth' were originally sharp ridges that had worn flat. So, after 
more than a year there appears to be minimal wear. I will get a few more 
years before I have to replace them.
Kit

13) From: Gerald and Beth Newsom
I'm glad to hear that since the Kitchenaid pro line is on my list of things
to get soon.
Gerald


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