The (soon to be) great "How's my crush?" Thread!

[day_trippr]

I use an extra bucket, fill it about 1/3rd to start, rest it on about a 45° angle atop my bench, then mist the grain as I rotate the bucket along the bench top which folds some of the grain over as I go along. Then I stop and stir by hand before adding the next third. Repeat until done.

As for rusting: I always reserve roughly one pound of dry base malt and run that through the mill at the very end to wick out most of the moisture. Also, it is important to start milling without a lot of delay after the last of the malt has been wetted. All we're trying to do is make the husk flexible, which is essentially done in a minute or so. Definitely do not want to allow the kernel to dampen as that will lead to loading up the rollers. I made the mistake of waiting 15 minutes before milling once and had to totally tear the mill apart to clean the roller knurling. Don't do that

Cheers!

 

[DuncB]

Interesting re the conditioning, I use a 30 litre rectangular storage bin, pour in the grain and spray and stir it all. Then clip the lid on and leave it for about 45 minutes to an hour. I've not had problems of mill gumming up but maybe Maltzilla different to a gnurled roller.
I don't bother to condition flaked products or roasted products and allow for these grain bill " losses " when I calculate the water. Again I go with 2% by weight.

Probably keeps the dust and static down as well.

 

[cmac62]

Is there a thread on how to condition malt before crushing, and a special mill I would need? Guessing my cereal killer would rust up if I tried using it wet.

I just spray it down till it starts sticking to my hand when I mix the water in. It is not really wet, but moist. Also, I have heard the idea of keeping 1 lb of the grist dry, run that last and it will dry off your rollers.

 

[bailey mountain brewer]

Definitely something I will be doing on my next batch, not just for the crush but as mentioned it likely keeps the dust down, and crushing 30 to 40 lbs of grain on average for a 15 gallon batch makes a lot of dust and I brew in my basement, soooo yeah dust sucks.

 

[DuncB]

Definitely something I will be doing on my next batch, not just for the crush but as mentioned it likely keeps the dust down, and crushing 30 to 40 lbs of grain on average for a 15 gallon batch makes a lot of dust and I brew in my basement, soooo yeah dust sucks.

Ohh you don't just cart the grain and mill upstairs and mill outside then bring it all back to the basement!!

 

[bailey mountain brewer]

No lie, I brewed this past sunday and said to my wife... Ya know if I could make the grain mill table portable then we could wheel it outside to mill. I have a walk out basement but the ramp is pretty steep and the table I built with a motor and pulley and also the hopper I built is a little awkward to move around.

 

[DuncB]

No lie, I brewed this past sunday and said to my wife... Ya know if I could make the grain mill table portable then we could wheel it outside to mill. I have a walk out basement but the ramp is pretty steep and the table I built with a motor and pulley and also the hopper I built is a little awkward to move around.

Ahh the maltzilla running on a battery sitting tight on a plastic bucket with the removable plastic hopper ( water container hacked ) is easy to move. Although I've fitted it well together and so actually do mill indoors without dust and it's nice and quiet.

 

[bracconiere]

just thought i'd update this thread with half way decent photos of my crush....this is 0.028" ran at brisk pace with a 1/2" drill

and here's an idea of the flour....

 

[hout17]

Here's my crush on 6lb 7 oz of Maris Otter at .032". Didn't shake the bucket this time. This is with the crop duster grain mill hand cranked at medium to turtle speed.

 

[bracconiere]

Here's my crush on 6lb 7 oz of Maris Otter at .032". Didn't shake the bucket this time. This is with the crop duster grain mill hand cranked at medium to turtle speed.

View attachment 744564

hmmm, looks good! maybe i should slow my drill down a bit, takes a bit longer for the strike water to heat up to temp anyway....

 

[Gusso]

Smashed through 17.5# of grain with my new Mighty Mill 3 for a Baltic Porter.

 

[user 298779]

Typical grist with Cereal Killer at 0.35”. Does this look consistent? Need to try mash in Spike Solo basket. Any finer it seems would allow too much grain to pass through bottom slots. Just doesn’t look well crushed…

slots..?

 

[Bassman2003]

Looks like quite a few whole kernels made it through. Did you use a measured .035 with shims? I use the same setup at ~.038 and do not get whole kernels. Here is a video I made about crushes if you have some time - it is 1 of 2.

 

[user 298779]

Yeah, I used my feeler gauges as with my older mills so I just don‘t get it. I moved the rollers apart and reset twice. First time I used my portable variable speed 20V cordless drill, slow speed. Tried different speeds on 1 (vs. 2 for higher speeds). Installed crank arm and did some manually….

That‘s an excellent video, well done! Thanks for posting. I’m not going to condition my grain; just don’t want to add effort/ steps - so I need to figure out why crush isn’t right. If I’m at 0.035” as Spike says is correct for setting then if I take the time & effort to hand crank I’d expect the grain to mill correctly….??

 

[Bassman2003]

Strange. Thanks! I have stayed with the very slow RPM for the drill speed and the crush is very good. As good as I can get without conditioning imho. Something must be off with the gap size or the whole kernels would not be present. I had some sneak by at .042 so I moved to .038

 

[day_trippr]

fwiw, my primary mill is a CK gapped at .032" for barley (using a legit feeler gauge) and I'd consider that pic above as needing another pass through a tighter gap...

Cheers!

 

[user 298779]

fwiw, my primary mill is a CK gapped at .032" for barley (using a legit feeler gauge) and I'd consider that pic above as needing another pass through a tighter gap...

Cheers!

Well,…I have Browne & Sharp dial calipers from tool & die shop - guess it’s time to check accuracy of the Advance Auto feeler gauge blades. When I figure this out I’ll post new photo

Cheers

 

[user 298779]

Strange. Thanks! I have stayed with the very slow RPM for the drill speed and the crush is very good. As good as I can get without conditioning imho. Something must be off with the gap size or the whole kernels would not be present. I had some sneak by at .042 so I moved to .038

Yeah and at .035” it’d be much finer. I don’t have my drill mounted so holding my hand. Good to hear you’re milling at low RPM because that’s what I’ve been trying.

Breaking out dial calipers from tool & die shop this morning to verify feeler gauge thickness’. Will post pic when I figure out what’s going on. Unless the retention screws are backing out allowing rollers to move apart (which they aren’t) then no reason to suspect to CM to be problem..

 

[IslandLizard]

Unless the retention screws are backing out allowing rollers to move apart (which they aren’t) then no reason to suspect to CM to be problem..

Re-measure/test the gap width after milling too. If it's wider, the roller moved, and the set screws didn't hold it in place.

On most mills, the non-driven roller needs to approach the driven one from underneath, for the set screws to hold it in place. The excenter adjuster on each side will need to be turned in opposite directions to achieve that. Look at the movement of the slave roller when turning the adjusters to see what I mean.

 

[user 298779]

Re-measure/test the gap width after milling too. If it's wider, the roller moved, and the set screws didn't hold it in place.

On most mills, the non-driven roller needs to approach the driven one from underneath, for the set screws to hold it in place. The excenter adjuster on each side will need to be turned in opposite directions to achieve that. Look at the movement of the slave roller when turning the adjusters to see what I mean.

Thanks for excellent feedback, understood Gap setting was same after milling. Still at .035. I have time to mess with it today so I’ll let you know.

Cheers

 

[day_trippr]

fwiw, I once bought a bag of base malt where the kernels were considerably smaller than what I was used to from the likes of Simpsons, Weyermann and Briess. A rather large portion of that malt passed through my mill apparently intact or very nearly so and it did affect the gravity of that batch enough to notice (like, 10 points off the expected pre-boil gravity!) A bit of experimentation prior to the next time I used that malt led me to tighten the gap down to five points (from .032 down to .027") which brought things back to expectations.

So, don't ignore the possibility, particularly when using a malt for the first time...

Cheers!

 

[IslandLizard]

Gap setting was same after milling. Still at .035. I have time to mess with it today so I’ll let you know.

Also feel the gap with an old, regular credit card (not the ones with the steel plate inside). They're typically 0.034". You should be able to just insert/remove it in a gap of that width, with some effort.

Looking at your crush above, it's hard to believe that being 0.035" with what looks like lots of whole kernels in there.
That's 2-row barley, right?
Does it look like that when you scoop it all the way through?

 

[user 298779]

fwiw, I once bought a bag of base malt where the kernels were considerably smaller than what I was used to from the likes of Simpsons, Weyermann and Briess. A rather large portion of that malt passed through my mill apparently intact or very nearly so and it did affect the gravity of that batch enough to notice (like, 10 points off the expected pre-boil gravity!) A bit of experimentation prior to the next time I used that malt led me to tighten the gap down to five points (from .032 down to .027") which brought things back to expectations.

So, don't ignore the possibility, particularly when using a malt for the first time...

Cheers!

Excellent input; that may be the cause because I was using old pale malt grains of unknown origin. The pisser with those situations is the smaller kernels may cause problems with Solo basket. Back to rice hulls even though Spike recommends not using them…

Cheers

 

[user 298779]

Also feel the gap with an old, regular credit card (not the ones with the steel plate inside). They're typically 0.034". You should be able to just insert/remove it in a gap of that width, with some effort.

Looking at your crush above, it's hard to believe that being 0.035" with what looks like lots of whole kernels in there.
That's 2-row barley, right?
Does it look like that when you scoop it all the way through?

2-row, and yes- all the way through… Makes me wish I still had my Phil Mill!

 

[bruce_the_loon]

i know i fueled it, but i swear i didn't start this...


but who was it that made a comment about drinking water and the nasty things fish do in it, and how he'd never drink it?

@Jayjay1976 if you feel like smackin some faces and getting this thread back on the rails with your earned "OP" sash on your avatar, feel free, lol

edit: i just want to see more crush porn!

Don't know if he is the one you are thinking of, but Sir Terry Pratchett wrote the following in Reaper Man.

"People have believed for hundreds of years that newts in a well mean that the water’s fresh and drinkable, and in all that time never asked themselves whether the newts got out to go to the lavatory."

 

[bracconiere]

Don't know if he is the one you are thinking of, but Sir Terry Pratchett wrote the following in Reaper Man.

"People have believed for hundreds of years that newts in a well mean that the water’s fresh and drinkable, and in all that time never asked themselves whether the newts got out to go to the lavatory."

at least they're still alive, if they were dead, you'd have cholera....

 

[user 298779]

Well,…I have Browne & Sharp dial calipers from tool & die shop - guess it’s time to check accuracy of the Advance Auto feeler gauge blades. When I figure this out I’ll post new photo

Cheers

So an initial update; CK is now milling 2-row nicely by hand. Attached photo is result after resetting gap to .035 and slow cranking. Thoughts? There was a good bit of flour in the mix but don’t think I’ll be a problem.

It would seem the non-driven roller had been slowly moving when using drill, even at low speeds. Thanks IslandLizzard; tightened the lock nuts very firmly again - so far so good.

I‘ll post another photo of results when I test with drill. Side note: it’s Weyermann grain in both pics. Smaller grain size. Will be milling Marris Otter 2-row soon.

Thanks for all the excellent feedback!

Cheers

 

[IslandLizard]

Attached photo is result after resetting gap to .035 and slow cranking.

Looks much better, far fewer, whole kernels.
Gap width (the numbers) really means nothing, it's the crush that ultimately needs to be tailored to the mash system.

My oat malt are very skinny needles. Similar to wheat and rye malt, I mill those separately on a very (very!) narrow gap. Otherwise, their tough, leathery husks don't open up to expose and crack the endosperm.
That's on a Monster Mill MM2 at low speed, ~150 rpm under load.

 

[user 298779]

Looks much better, far fewer, whole kernels.
Gap width (the numbers) really means nothing, it's the crush that ultimately needs to be tailored to the mash system.

My oat malt are very skinny needles. Similar to wheat and rye malt, I mill those separately on a very (very!) narrow gap. Otherwise, their tough, leathery husks don't open up to expose and crack the endosperm.
That's on a Monster Mill MM2 at low speed, ~150 rpm under load.

Do you think you could run that through Spike Solo basket? I guess being patient to get mashbed set and recirc times correct it’d work.

 

[IslandLizard]

Do you think you could run that through Spike Solo basket? I guess being patient to get mashbed set and recirc times correct it’d work.

I don't have such system, or even worked with one, so I don't know how it will fare.

The grain pieces on top look fairly coarse, similar to kernels cracked into 3 pieces, a reasonable standard for a mash that's being fly sparged. How well the mash recirculates and lauters depends on how much powder there is, which reduces permeability. There's only one way to find out.
If you have any rice (or oat) hulls around, and the mash recirculation plugs up, you can stir in a few handfuls of those to increase permeability. Then start widening the gap a tad on the next few brews until the results are good.

 

[k-daddy]

I brewed yesterday and conditioned the grain with water @ 2%. My Monster Mill, 2” diameter/ 2 roller was gapped to .025. Crush looked good but there were intact grains… soldiered on anyway. Ended up being way off on efficiency. 1.054 instead of the targeted 1.062. 2 kettle rims setup with no sparge. I do like the lack of dust and minimizing a stuck mash so will continue to condition. Next time, I’m going to close the gap to .022 and see if that’s enough to make a difference. I do think that posts involving grain crush/gap settings/etc. should specify if the grains were conditioned or not… it would help to reduce one of the many variables when talking grain crush.

 

[doug293cz]

I brewed yesterday and conditioned the grain with water @ 2%. My Monster Mill, 2” diameter/ 2 roller was gapped to .025. Crush looked good but there were intact grains… soldiered on anyway. Ended up being way off on efficiency. 1.054 instead of the targeted 1.062. 2 kettle rims setup with no sparge. I do like the lack of dust and minimizing a stuck mash so will continue to condition. Next time, I’m going to close the gap to .022 and see if that’s enough to make a difference. I do think that posts involving grain crush/gap settings/etc. should specify if the grains were conditioned or not… it would help to reduce one of the many variables when talking grain crush.

Did you have any small kernel grains, like wheat, in your grain bill? Even then, it seems implausible that kernels would make it thru a 0.025" mill gap unbroken. Did you check (roll between your thumb & fingers) to see if the "intact" kernels had been cracked, but not separated into pieces? Any idea what your mill RPM was?

Brew on

 

[k-daddy]

Did you have any small kernel grains, like wheat, in your grain bill? Even then, it seems implausible that kernels would make it thru a 0.025" mill gap unbroken. Did you check (roll between your thumb & fingers) to see if the "intact" kernels had been cracked, but not separated into pieces? Any idea what your mill RPM was?

Brew on

Thanks for your reply. No, nothing unusually small in the grain bill. There were some intact kernels which I probably should've addressed prior to mashing. Seems the 2% water conditioning made the husks pliable enough to squeeze through undamaged. I have an All American Ale Works 1/2 hp motor running @ 180 rpm's.

 

[bracconiere]

Thanks for your reply. No, nothing unusually small in the grain bill. There were some intact kernels which I probably should've addressed prior to mashing. Seems the 2% water conditioning made the husks pliable enough to squeeze through undamaged. I have an All American Ale Works 1/2 hp motor running @ 180 rpm's.

could the whole ones slipped by on the edge of the rollers? my mill has a chute that feeds the grain to the middle, but i've seen some don't have that...

 

[IslandLizard]

My Monster Mill, 2” diameter/ 2 roller was gapped to .025. Crush looked good but there were intact grains…

Did the gap move perhaps?
When adjusting the (slave) roller it needs to approach the driven one from underneath, so it digs into the lock screws when force (from crushing grain) is applied.

[Edit] And the direction of turning the excenter is opposite on each side, of course.

 

[doug293cz]

Thanks for your reply. No, nothing unusually small in the grain bill. There were some intact kernels which I probably should've addressed prior to mashing. Seems the 2% water conditioning made the husks pliable enough to squeeze through undamaged. I have an All American Ale Works 1/2 hp motor running @ 180 rpm's.

Roller speed doesn't appear to be an issue.

The tougher husks, due to conditioning, could be holding cracked kernels together, so they look like uncrushed kernels. That's why you should check them to see if they are easy to break apart. Even if they are broken, they might not gelatinize as fast as fully separated grits (since being held in the husk could limit water access), which would slow down conversion of these grits.

Your OG of 1.054 vs. the expected 1.062 is about 100% * (54 - 62) / 62 = -13% lower than target. For this to be due exclusively to uncrushed kernels, you would have to have had about 13% uncrushed kernels in your grist. Did it look like you had anywhere near that many in your grist?

Uncrushed, or poorly crushed, grain primarily affects the conversion efficiency component of mash efficiency (mash efficiency = conversion efficiency * lauter efficiency.) You can measure the conversion efficiency of your mash by testing the SG of the wort in the mash (after stirring well to insure wort homogeneity) by using the method described here. You can test during your mash, and extend the mash as necessary to get 95% or above conversion efficiency.

Gotta ask: do you normally do a sparge and decided not to with this batch? If so, and you didn't take the lauter efficiency difference between sparge and no-sparge into account, this could explain your low SG.

Brew on

 

[MaxStout]

Thanks for your reply. No, nothing unusually small in the grain bill. There were some intact kernels which I probably should've addressed prior to mashing. Seems the 2% water conditioning made the husks pliable enough to squeeze through undamaged. I have an All American Ale Works 1/2 hp motor running @ 180 rpm's.

When you measured the gap, did you clean the rollers first? A coating of debris might affect the actual gap.

 

[k-daddy]

could the whole ones slipped by on the edge of the rollers? my mill has a chute that feeds the grain to the middle, but i've seen some don't have that...

My hopper feeds the grain to towards the center of the rollers but who knows once the grains get underneath.

 

[k-daddy]

Did the gap move perhaps?
When adjusting the (slave) roller it needs to approach the driven one from underneath, so it digs into the lock screws when force (from crushing grain) is applied.

[Edit] And the direction of turning the excenter is opposite on each side, of course.

No, the gap didn’t change. I have one of the newer MM and the gap is set with a bolt instead of the older, set screw models.

 

[k-daddy]

Roller speed doesn't appear to be an issue.

The tougher husks, due to conditioning, could be holding cracked kernels together, so they look like uncrushed kernels. That's why you should check them to see if they are easy to break apart. Even if they are broken, they might not gelatinize as fast as fully separated grits (since being held in the husk could limit water access), which would slow down conversion of these grits.

Your OG of 1.054 vs. the expected 1.062 is about 100% * (54 - 62) / 62 = -13% lower than target. For this to be due exclusively to uncrushed kernels, you would have to have had about 13% uncrushed kernels in your grist. Did it look like you had anywhere near that many in your grist?

Uncrushed, or poorly crushed, grain primarily affects the conversion efficiency component of mash efficiency (mash efficiency = conversion efficiency * lauter efficiency.) You can measure the conversion efficiency of your mash by testing the SG of the wort in the mash (after stirring well to insure wort homogeneity) by using the method described here. You can test during your mash, and extend the mash as necessary to get 95% or above conversion efficiency.

Gotta ask: do you normally do a sparge and decided not to with this batch? If so, and you didn't take the lauter efficiency difference between sparge and no-sparge into account, this could explain your low SG.

Brew on

Thanks Doug, all great intel. Will have to dial in my crush for the next brew. I’ve narrowed the gap and will run just a handful of grain and check it before milling the entire amount. As for the sparge (with my 2 kettle RIMS setup), holding back the sparge water would reduce the total fluid volume for the mash recirculation and create a situation where my boil kettle (heat source) would not have enough fluid to cover the element as most of the fluid is in the MT to cover the top of the mash. I’ve just learned to live with less efficiency. I do a mash out and squeeze the brew bag to get the most I can out of the process. I don’t have the space for a 3 vessel setup.