Recommended Mill Setting

[SG9090]

I was just wondering is there a standard mill thickness, or further to the point what thickness are you milling to?

 

[Fourstar]

im currently milling at 1.1mm but thinking of opening that to 1.3-1.4mm as im getting alot more flour than what i would like and consequently a slower inconsistent sparge. The joys of milling with a drill i suppose.

IIRC my monster mill came stock at 0.040 - 0.045 of an inch, aka 1.1mm~ and most seem to get good results with this. in a perfect world you are shooting for a kernel thats had the grain pulverised inside but not excessivly torn, achievable is a cracked husk and the kernel broken into 3 pieces~ with minimal flour.

 

[Zwickel]

Standard over here is around 0.8mm gap.

:icon_cheers:

 

[felten]

Im using .035"

 

[peaky]

I've been milling with a Monster Mill MM-2 with a gap set at 1.1mm, the grain looked like it was not cracked enough and my efficiency is pretty average so I have changed the gap to 0.9mm. I ran a kilo through it and it's looking much better, haven't brewed with grain crushed at this setting yet though.

Before I got the MM-2 I was getting my grain cracked at LHBS and my efficiency was much better. I reckon the setting of 1.1mm is killing my efficiency, I'll find out next brew day :icon_cheers:

 

[Greg Lawrence]

I originally had my millmaster set to the middle setting, not sure of the mm, but it was doing a great job, getting around 75% efficiency.
Before milling my grain on Friday night, I had the bright idea to adjust the mill to get a finer crush and maybe up my efficiency.
After 27 all grain brews I had never had a stuck sparge. Now I know what a stuck sparge is all about. Yes my effiency was better, but if a 3 hour sparge is the price you have to pay for efficiency, I'll stick to my 75%.

 

[gregs]

SG9090 Fourstars description of what a good crush may look like is a good one. When discussing preferred grain mill gap, not much is said about mill speed or roller speed which I feel has a great influence on the quality of your crush after selecting a gap setting your happy with.

I had experience with this as a friend of mine Budwiser built me a beautiful 4 inch mill. And after hours of fine adjustments to the gap the only marked improvement on the crush was a slower roller seed, a reduction of roller surface speed from 813 millimetres per second down to 480 millimetres per second had an astonishing result on the quality of the crush, so much so I could hardly believe the difference.

Sorry for the ramble guys but I feel this is the simplest single improvement I have made to my system.

Cheers.gregs.

 

[QldKev]

SG9090 Fourstars description of what a good crush may look like is a good one. When discussing preferred grain mill gap, not much is said about mill speed or roller speed which I feel has a great influence on the quality of your crush after selecting a gap setting your happy with.

I had experience with this as a friend of mine Budwiser built me a beautiful 4 inch mill. And after hours of fine adjustments to the gap the only marked improvement on the crush was a slower roller seed, a reduction of roller surface speed from 813 millimetres per second down to 480 millimetres per second had an astonishing result on the quality of the crush, so much so I could hardly believe the difference.

Sorry for the ramble guys but I feel this is the simplest single improvement I have made to my system.

Cheers.gregs.

Agreed there are many factors here to what a perfect crush is.

Fourstars description is an excellent starting point.
but take into account
BIAB = finer crush
3V = medium crush
3V recirc (HERMS, RIMS) = courser crush.

So what works for 1 brewer may not work for your system. Remember get ideas, but you need to apply the information to your system.


Also Gregs point about mill surface speed is excellent.
I have recently put a motor on my MM2, changing the roller surface speed from 596mm per sec (at 300rpm) down to 318mm per sec (160rpm). Prior I was about to adjust my rollers a bit wider as I was getting too much flour, with the speed change I now have a better crush.

Also some mill designs such as a 3 roller mill is designed to flatten the grain on first contact and on second contact mill the grain. This allows you to crush at higher speeds.

Finally as I have found a higher roller speed may not mean a quicker crush. With slowing my mill down I still actually take about the same time to crush (tested at 2min 20secs for 5.5kg grain) So what is happening in my system is I am limited by the hopper feed size. Thinking about it, as I write this, limiting the feed area too much may also result in torn husks as the roller speed is moving faster than the grain feed speed.


QldKev

 

[goomboogo]

SG9090, as others have pointed out, it will depend on how you choose to brew. Are you going to use an infusion system with a mash tun/false bottom, a recirculating system, BIAB or something else altogether. Also, what mill are you planning on using and how are you going to drive it (hand or motorised)?

I brew on a basic, gravity fed 3 vessel system with a cylindrical water cooler tun with a 9 inch false bottom. To mill grain, I hand crank a 2 roller monster mill set on 0.9mm. The crush is pretty much as per the descriptions in various texts and on my set-up, results in efficiencies that I'm happy enough with as well as sparging that is non-problematic.

So, as with many things in brewing, it will depend on what type of set-up you plan on using.

 

[peaky]

I have recently put a motor on my MM2, changing the roller surface speed from 596mm per sec (at 300rpm) down to 318mm per sec (160rpm).

Hi QldKev,

I also have a MM-2 and would like to motorise it. What motor did you use and what gear ratio did you use? The old power drill I'm using is pretty hard to judge what speed it's actually rotating at, especially when it's rocking around on a bucket. Definitely keen to bench mount and motorise my mill.

Cheers

 

[QldKev]

Hi QldKev,

I also have a MM-2 and would like to motorise it. What motor did you use and what gear ratio did you use? The old power drill I'm using is pretty hard to judge what speed it's actually rotating at, especially when it's rocking around on a bucket. Definitely keen to bench mount and motorise my mill.

Cheers

I went the 'AndrewQld' setup

Motor
http://secure.oatleyelectronics.com//produ...9ed62ed1d74e03c
This is a 24vdc motor, if you run half the volts you get half the speed.


Spider coupler
http://jaycar.com.au/productResults.asp?ke...keyform=KEYWORD
I drilled both ends of the coupler out to suit the motor and mill.

Power supply
Any 12v one that can produce decent amps
I'm using an old Computer PSU, that has 12v 8amps output, that I already had at home.
AndrewQld uses a 12v 12amps (or was it 16amps?) one.

Here's a pic of how easy it is to setup. No big / expensive pulleys etc.


I didn't have 2 brakets thats matched, but they are not on display so all is good.
Also the 2 bits of pine withside of the mill is to help reduce any dust from the mill.



QldKev

 

[MHB]

Crushing is a very complex question; I don't want anyone to think of this as an add, but I get through a lot of malt every month and it's a bigger range of malts than any home brewer could possibly use. As a retailer we have to crush for dozens of brewers using different systems who all have their own thoughts on how they want their malt crushed.

I'm lucky to have a really good mill; it has large 175 mm powered rolls, flutes rather than knurling and very importantly for me it's really quick to adjust. Shawn at Murrays has the same type of mill and he has his locked at 1.5 mm, but like most commercial brewers he is mainly crushing one type of malt. At a Craft/Retail level its different, we are never crushing anything like the same malt bill twice (that's why a quick adjuster is necessary). I find as a general rule UK malts are shorter and fatter, German/Belgian next fattest and Australian malt to be the longest and thinnest.
We always run grain through the mill at least twice; if there is a lot of wheat (over 10%) it gets crushed first, then mixed with the barley and remilled, I find wheat if crushed to its final size (~0.5 mm) in one pass generates a lot of flour but if you sneak up on it a bit you can get a very fine kibble and very little flour.

As an example of what I'm talking about the last beer I brewed was a Belgian Wheat, Made up of: -
Dingemans Pilsner 58% Crushed to 1 mm
Wheat (Un-Malted Australian) 34% crushed to 0.5 mm
Malted Oats (UK) Crushed to 0.1 mm
The three malts were obviously crushed separately then mixed by running through the mill, this is them before mixing. I got 83% brewhouse yield so what I did worked.


Left to right Oat, Wheat, Pilsner


It's far from just being a question of "Mill Gap", the size of the rollers, the surface, whether they are powered or one or more are idling, the surface speed, the material being crushed, and the speed of flow of the malt into the rollers are all probably just as important as the gap. The moisture content of the grain, the equipment the grist is going to be used on are also very important.
For me the biggest single factor is how fast you lauter, if you go slow enough very coarse crush (search Floating Mash) can give the same yield as a fine one, and who can forget TB's experiment where he got 45% extraction from uncracked malt (surprised the hell out of me).

So your system, how you use it, what you are crushing are all just a part of the picture.

Good brewing

Mark


PS
Been serving and working on this in bits, some people have posted similar thoughts while I've been busy.
M

 

[goomboogo]

MHB's post highlights a glaring omission in mine. I should have noted the mill setting I use is primarily used with a limited range of base malt, mostly M.O and Golden Promise.

 

[Goofinder]

My mill is set to about the thickness of a metal ruler that was lying around. I run the grain through twice. It looks like a reasonable crush to me and I get pretty good efficiency, so I'm happy enough. :icon_cheers:

 

[SG9090]

Hey Guys,

Thanks for your replys.
I am a new Ag brewer with a Herms system i built. Only brewed 3 times on it so now still learning my way around it, and having a great time. I did not realise the complexity of milling grain, honestly though it would be a simple question. After reading your posts, im not actually sure what to say other than i need to think about what you have said, figue out what im trying to do and change one thing at a time i guess.
Thanks for your imput.

Shane

 

[peaky]

I went the 'AndrewQld' setup

Cheers for the info, I've had a look around at different motors, set-ups etc and this looks like the best value for money, easiest to set up, and great for getting the roller speed right.

One motorised MM-2 coming right up! :super:

 

[QldKev]

Cheers for the info, I've had a look around at different motors, set-ups etc and this looks like the best value for money, easiest to set up, and great for getting the roller speed right.

One motorised MM-2 coming right up! :super:

I thought it was a cool setup, not pulleys to get your fingers caught in, and no expensive of the bits.



I've started to put up a site with some junk for projects;
The best site in the world; lol
It's got some more info on my mill setup.

QldKev

 

[Fourstar]

im currently milling at 1.1mm but thinking of opening that to 1.3-1.4mm as im getting alot more flour than what i would like and consequently a slower inconsistent sparge. The joys of milling with a drill i suppose.

for those milling with a drill.

I opened my gap to 1.2mm today, (it was actually .9 earlier, not the standard 1.1mm aqs it should be) and milled the best grain i have seen from my mill and possibly as good as i have experienced with a LHBS. A perfect kernel break w/ grist into several pieces and almost no flour. best thing is all kernerls have been broken! (oberved by rubbing several handfulls of grain between palms and none displayed unbroken kernels.)

if you use a drill. try this gap. If its a corded drill, mill by pulsing as the rpm is typically higher. It's displaying how it should look and not alot of it pulverised to flour. I'll report the efficiency once my brewday is done and see how she fairs. i usually hit around 68-73% dependant on grist+-adjuncts. all i can say is I'm happy. :beerbang:

 

[Fourstar]

for those milling with a drill.

I opened my gap to 1.2mm today, (it was actually .9 earlier, not the standard 1.1mm aqs it should be)...

... I'll report the efficiency once my brewday is done and see how she fairs. i usually hit around 68-73% dependant on grist+-adjuncts. all i can say is I'm happy. :beerbang:

Ok so it hit 68% efficiency with a beautiful lauter. I batch sparge and it typically takes 10L or so before the second runnings becomes bright and generally ends up as a trickle/slow flow which gets close to being stuck on the second sparge. throw some adjunct in there and im ususally looking at 3 very slow batch sparges.

Yesterday i had two awesome runoffs, i probabaly could have opened the valve full tilt but declined just to ensure the runoff was smooth. a A really quick runoff nonetheless w/ bright wort into the kettle and brewhouse efficiency as expected for MY system.

To be able to see a crush by a drill and there is SFA flour, couple that with good brewhouse results has put a on my dial!

 

[cdbrown]

Fourstar - when you do your next batch could you take some close ups of the milled grain?

I'm using a powered drill on the slowest setting and I reckon it's too quick. I've gone to conditioning the malt by spraying some warm water on the grains as I pour it into the hopper and this has reduced the powder, but there's still a fair amount of powder. After listening to some of the brewstrong podcast I'm probably ripping the husk with the high speed. Might open the gap a notch on the millmaster and see what it does to the 4kg of malt I still need to mill for the batch tonight.

Hopefully the larger gap will allow me to recirc through the HERMS at full throttle during the mash without the bed compacting which I've had a couple of times in the past. The larger gap might mean I can open up the adjustable feed to the mill a bit more, took about 30mins to mill 8kg galaxy this morning as I can feed too fast or drill is overwhelmed (could also be a sign that the gap is too small). Millmaster is set with the notch 1 position left of top when looking at the side with the shaft.

That motor and coupler looks the good Kev.

Looking at MHBs pic there's heaps of shredded kernals there. Looks far more destroyed than I'd expect people would want.