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General Category => All Grain Brewing => Topic started by: Philbrew on November 20, 2015, 11:23:53 pm

Title: Grain mill roller spacing?
Post by: Philbrew on November 20, 2015, 11:23:53 pm
I'm about to make the jump to all-grain.  Bought a Cereal Killer grain mill from AIH.  Looks well built and has gap adjustment but came with no instructions.  Gap as delivered looks about 1/8" which does nothing to grain.  What should I set the gap to?  Starting out with Weyermann Pils base malt and doing BIAB (The Brew Bag).
Also, I want to drive it with a cordless drill.  Is there a preferred RPM range?
Title: Re: Grain mill roller spacing?
Post by: klickitat jim on November 21, 2015, 12:00:11 am
I have a CK. I set it at tightest gap and I run it with a plug in hammer drill, with hammer function turned off, and it has a dial stop on the trigger. I set it to the slowest speed that won't slow down when grain is added. Guessing about 200-300 rpm. I cut the power cord and wired it to a waterproof switch, from the switch it runs to a standard grounded plug in.
Title: Re: Grain mill roller spacing?
Post by: mabrungard on November 21, 2015, 06:14:09 am
Gap setting is dependent upon your mashing system. Ideally, you want the crush to be very fine. But that invites plugging the mash and preventing runoff. For starters, I'd suggest a gap of around 0.04" to 0.045" and see how that works in your system. If the runoff rate is pretty high for you, then reduce the gap over successive batches.

I run 0.036" in my Monster 2.2, but I condition my grain prior to crushing and that leaves my crush with a lot of flour and intact husks. Perfect for high extraction efficiency and wort flow. I use one of that Harbor Freight Low-Speed Drills at the lowest speed that it can stand and I can tell you it takes a lot of power. I'd be surprised if a cordless drill would last in that sort of service.

Title: Re: Grain mill roller spacing?
Post by: jeffy on November 21, 2015, 07:27:37 am
Gap setting is dependent upon your mashing system. Ideally, you want the crush to be very fine. But that invites plugging the mash and preventing runoff. For starters, I'd suggest a gap of around 0.04" to 0.045" and see how that works in your system. If the runoff rate is pretty high for you, then reduce the gap over successive batches.

I run 0.036" in my Monster 2.2, but I condition my grain prior to crushing and that leaves my crush with a lot of flour and intact husks. Perfect for high extraction efficiency and wort flow. I use one of that Harbor Freight Low-Speed Drills at the lowest speed that it can stand and I can tell you it takes a lot of power. I'd be surprised if a cordless drill would last in that sort of service.
Martin, he mentioned he uses brew in a bag, so I think he can crush as fine as is possible.
Title: Re: Grain mill roller spacing?
Post by: Philbrew on November 21, 2015, 10:04:46 am
Gap setting is dependent upon your mashing system. Ideally, you want the crush to be very fine. But that invites plugging the mash and preventing runoff. For starters, I'd suggest a gap of around 0.04" to 0.045" and see how that works in your system. If the runoff rate is pretty high for you, then reduce the gap over successive batches.

I run 0.036" in my Monster 2.2, but I condition my grain prior to crushing and that leaves my crush with a lot of flour and intact husks. Perfect for high extraction efficiency and wort flow. I use one of that Harbor Freight Low-Speed Drills at the lowest speed that it can stand and I can tell you it takes a lot of power. I'd be surprised if a cordless drill would last in that sort of service.
Thanks Martin,
I have an old Milwaukee 1/2" corded drill with bags of torque.  That sounds like the answer using Jim's switch idea.

Have not heard of "grain conditioning"...must do some research.
Title: Re: Grain mill roller spacing?
Post by: denny on November 21, 2015, 10:17:14 am
I crush very fine and have no problems without conditioning.  I'd skip that step until you  if you need it.  Knowing what the gap is on someone else's mill won't necessarily do you much good.  I have no idea what mine measures.  I judge by the crush, not the measurement.
Title: Re: Grain mill roller spacing?
Post by: mabrungard on November 21, 2015, 01:11:23 pm
I brew with RIMS, so the permeability of the mash bed is critical for my brewing. Conditioning makes a HUGE difference in a system that needs flow!
Title: Re: Grain mill roller spacing?
Post by: a10t2 on November 21, 2015, 01:50:08 pm
I have a Barley Crusher and crank it by hand, so like Denny said it may not be applicable, but I crush at 0.030". That's an easy setting/check because it's the thickness of credit card stock.
Title: Re: Grain mill roller spacing?
Post by: brewinhard on November 21, 2015, 04:51:58 pm
+1 to barley crusher as well and crankin' by hand.  Sucks though when the batches get close to 20#.  I just look at it as a good workout.  Run mine at the factory setting which I think is .039.  I have another older crusher too that I recently took apart and cleaned and set this one back up a bit lower (smaller gap) to deal with rye and wheat malt. 
Title: Re: Grain mill roller spacing?
Post by: gspot on November 22, 2015, 05:36:29 am
New CK owner here too. I use the credit card trick also, and it works great.

Sent from my SM-T320 using Tapatalk

Title: Re: Grain mill roller spacing?
Post by: Steve Ruch on November 22, 2015, 10:02:04 am
I'm about to make the jump to all-grain.  Bought a Cereal Killer grain mill from AIH.  Looks well built and has gap adjustment but came with no instructions.  Gap as delivered looks about 1/8" which does nothing to grain.  What should I set the gap to?  Starting out with Weyermann Pils base malt and doing BIAB (The Brew Bag).
Also, I want to drive it with a cordless drill.  Is there a preferred RPM range?

E-mail them and tell them that you want the instructions; not including them had to be a mistake on their part.
Title: Re: Grain mill roller spacing?
Post by: erockrph on November 22, 2015, 01:58:09 pm
I BIAB and have settled on 0.88mm (roughly 0.035"). It works for my setup, and it's easy to set/check my gap with one of the dozens of these I have laying around:

(http://ecx.images-amazon.com/images/I/61CPlWlNiTL._SY355_.jpg)
Title: Grain mill roller spacing?
Post by: Wort-H.O.G. on November 22, 2015, 04:25:53 pm
i have a feeler mil gauge to measure. for malts other than wheat-i use .029. for wheat i use .025.
Title: Re: Grain mill roller spacing?
Post by: Philbrew on November 22, 2015, 06:23:50 pm
So, from all of the above, it looks like I should set the gap in the 0.030-0.040 inch range and fine tune from there as I get experience with my brew set-up and styles.
Title: Re: Grain mill roller spacing?
Post by: klickitat jim on November 22, 2015, 06:51:18 pm
So, from all of the above, it looks like I should set the gap in the 0.030-0.040 inch range and fine tune from there as I get experience with my brew set-up and styles.
Yup
Title: Re: Grain mill roller spacing?
Post by: erockrph on November 22, 2015, 08:36:55 pm
So, from all of the above, it looks like I should set the gap in the 0.030-0.040 inch range and fine tune from there as I get experience with my brew set-up and styles.
Yup
+1 - visually inspect your crush as well. My settings on my mill may not give the same results on yours. But that's as good a starting point as any.

Sent from my XT1585 using Tapatalk

Title: Grain mill roller spacing?
Post by: tommymorris on November 22, 2015, 08:49:24 pm
One thing about these gap settings; one man's 0.030" is another's 0.035". I may set for a tight 0.035" and you a loose 0.030" and we may have the same actual gap.
Title: Re: Grain mill roller spacing?
Post by: Philbrew on November 22, 2015, 10:05:00 pm
So, from all of the above, it looks like I should set the gap in the 0.030-0.040 inch range and fine tune from there as I get experience with my brew set-up and styles.
Yup
+1 - visually inspect your crush as well. My settings on my mill may not give the same results on yours. But that's as good a starting point as any.

Sent from my XT1585 using Tapatalk
  "visually inspect your crush as well".  What am I looking for?  Husk size?  Flour amount?  Particle size/amount vs. flour amount vs. husk amount?  You can tell that I haven't done any crushing yet, cuz I don't even know what questions to ask.  Sorry! :-[
Title: Re: Grain mill roller spacing?
Post by: erockrph on November 23, 2015, 08:29:18 am
So, from all of the above, it looks like I should set the gap in the 0.030-0.040 inch range and fine tune from there as I get experience with my brew set-up and styles.
Yup
+1 - visually inspect your crush as well. My settings on my mill may not give the same results on yours. But that's as good a starting point as any.

Sent from my XT1585 using Tapatalk
  "visually inspect your crush as well".  What am I looking for?  Husk size?  Flour amount?  Particle size/amount vs. flour amount vs. husk amount?  You can tell that I haven't done any crushing yet, cuz I don't even know what questions to ask.  Sorry! :-[
You don't want the husks to be shredded - you want them to be as intact as you can. You want the kernel to be crushed as fine as you can without a lot of flour (think grits). Having said that, if you're doing BIAB, then you can get away with a lot of flour without an issue, since you don't have to worry about lautering.
Title: Re: Grain mill roller spacing?
Post by: a10t2 on November 23, 2015, 09:12:21 am
  "visually inspect your crush as well".  What am I looking for?  Husk size?  Flour amount?  Particle size/amount vs. flour amount vs. husk amount?  You can tell that I haven't done any crushing yet, cuz I don't even know what questions to ask.  Sorry! :-[

With a two-roller mill, you're looking for all the husks to be opened, but preferably not shredded into more than 2-3 segments per kernel, and some flour, but mostly endosperms that are also split into 2-3 uniform chunks. Numerically, approximately half the material (by mass) retained by a #14 sieve, half the remainder by a #30 sieve, half *that* remainder by a #60 sieve, and what's left (~10%) as flour. The full ASBC method breaks it down even further but is overkill for actual brewing IMO.

A good overview: http://www.brewingwithbriess.com/Assets/Presentations/Briess_2007CBC_Practical_Milling.ppt
Title: Re: Grain mill roller spacing?
Post by: denny on November 23, 2015, 10:14:19 am

You don't want the husks to be shredded - you want them to be as intact as you can. You want the kernel to be crushed as fine as you can without a lot of flour (think grits). Having said that, if you're doing BIAB, then you can get away with a lot of flour without an issue, since you don't have to worry about lautering.

There's quite a bit of flour in my crush, but my lauter system doesn't care.  But I've learned that through experience.  It's best to start a bit on the conservative side and go from there.
Title: Re: Grain mill roller spacing?
Post by: coolman26 on November 23, 2015, 03:50:25 pm
I use a MM-3 mill and fly sparge with a manifold.  My copper manifold is made with slits I cut with my porta-band saw.  I hadn't measured my gap since moving to fly.  I measured mine and it is .032.  When I run wheat I just run it through twice.  I've never had a stuck sparge with this setup.  I tried conditioning and really didn't think it made any difference for me.  It really is system dependent, not any cure all number.     
Title: Re: Grain mill roller spacing?
Post by: Steve L on November 24, 2015, 07:12:57 pm
I have a Barley Crusher and crank it by hand, so like Denny said it may not be applicable, but I crush at 0.030". That's an easy setting/check because it's the thickness of credit card stock.

This is me as well. I hand crank my Cereal Killer and I just set the gap at a credit card thickness. I can't afford a gap gauge.  ;)