Grain Crush

[TasChris]

Hi all,
Sorry but this could be a long post!!
After 4 AG brews I am concerned by the poor efficiency that I am getting, has varied from 58% to 63%, I believe it could be linked to my crush.
The first batch was grain crushed by HBS but the last 3 have been crushed by me using a Barley Crusher. I have used it with the settings that it came set on.
The drill I use has little to no control on speed and I feel that I am crushing too fast.
The grains I have been using have been largely JWM Trad and Pilsner.

I conducted a test varying number of passes, hand cranking the mill, using the drill to drive it and wetting the grains (2% water by weight)

1 Pass hand cranked, no water added.
All grain cracked, little flour some of contents of the grains are still within the husk


2 Pass hand cranked, no water added.
All grain cracked and most of the husks are now empty, 3 times as much flour as 1 Pass.


1 Pass drill cranked, no water added.
All grain cracked, little flour some of contents of the grains are still within the husk. Grains more shredded than hand cranked


2 Pass drill cranked, no water added.
All grain cracked and all of the husks are now empty. 4 times as much flour as 1 Pass. Grains more shredded than hand cranked.


1Pass hand cranked, 2% water added.
Grains squished and split but 90% of grains largely intact


2Pass hand cranked, 2% water added.
Grains squished and split but 50% of grains largely intact. Some flour.


1Pass drill cranked, 2% water added.
Grains squished and split but 80% of grains largely intact


1Pass drill cranked, 2% water added.
Grains squished and split but 40% of grains largely intact. More flour than hand cranked 2 pass.



In conclusion there was more shredding of the husk, more separation of the husk from the contents and more flour generated by the drill than by hand and by 2 passes compared to 1.

Grain that had been wetted seemed to shatter less and the grains were more intact with the husks still surrounding the guts of the grain (technical jargon). The grains appeared to have been rolled and not shredded at all.


My gut feel is the 2 pass by drill or hand with no water added would appear to more suitable for increasing efficiency but probably increasing the risk of stuck sparge.

Any thought/comments
Sorry about the length of the post!!

Chris

Edited to add in pics

 

[Justin]

Hi Chris,

I have a barley crusher as well. I have it set so that the lines/notches marked on the roller adjustment are 1.5-2mm narrower than the standard factory setting. Hope you follow that? This has given me a good crush and efficiency with no issues with sparge.

One time recently when someone had borrowed and been playing with my grain mill I didn't realise the settings were set on the factory setting and I got 65%. I couldn't work out why until I went to mill the next lot of grain on the next batch and realised the settings had been changed.

I'd be careful of milling wet grain in the rollers given that they are only steel and not stainless, if your really careful to clean them out after use and dry it it shouldn't be a problem but if you leave moist flour dust on them they may rust??

I just do a single pass. I used to use a 14.4V Ryobi cordless drill on a slow setting and it gave a nice slow crush but it was murder on the drill. I then bought a cheap 1/2" XUI electric drill from bunning but it has no torque at slow speeds and I was just going to burn out the windings on the motor (I have seen smoke from it a number of times ). It shreded the hell out of the husks when I couldn't keep it slow.

I finally settled on a windscreen wiper motor that I have discussed and shown photos of on this site. It's works well for me, it's slow but gives a nice crush. I jimmied up and adapter to couple the two shafts together but I think Warren has used a spider coupling from Jaycar to couple up his which I think is a nice option.

Good luck.
Justin

 

[Pumpy]

Tas Chris , I have seen so many people crush differently and still get results I am usure how fussy one has to be.

Grumpy stated somewhere 'Crush as fine as you can without getting a stuck sparge'


I wet leave 15 mins crush about 0.7 mm and things are great but I dont have a heavy knurl ,I get a lot of flour (brewers talk about 30% flour as good ) but I get more than 30%
However the husk is niceley intact .


Pumpy

 

[Stuster]

I think Justin's advice is good. I have a BC as well but just crush by hand. (Good exercise. ) Crush finer until you get a stuck sparge, then back off a bit. I recently tried the wet grain method and it doesn't seem to work very well with the BC.

One thing that I did to improve my efficiency was calculate it right. Jayse pointed out on one thread that the volume you use to calculate the efficiency is not the volume into the fermenter, but the volume in the kettle. Added 10% to my efficiency, just like that. :super:

 

[TasChris]

Just added a couple of pics, stuffed up first time.
Thanks For the info Justin, Suster and Pumpy I will adjust my spacing.
My current drill also has no torque at low speed so starting fast the slowly backing of the pace seems to load up the drill.
Might have to go back to hand cranking till I can sorce a wiper motor.

I think I have challenged Pistol for longest post but not on most words per post

 

[Airgead]

Tas

Sounds like your crush is too coarse. You shouldn't be ending up with intact squished grains. I don't have a barley crusher so I'm not sure what the default is there. My mill (crankandstein) is set to .7mm which is finer than usual. I think most people use about .9mm or so. .7 gives me a very fine crush but the husks are still intact and I have never had a problem with a stuck mash (though I have probably just jinxed myself). I used to use .9 and was getting about 70% efficiency with the grains you mentioned. I wound it down to .7 and am now getting about 80% or so.


Cheers
Dave

 

[Justin]

Yeah, it is too coarse Dave on the factory setting.

The Barley Crusher has quite a severe knurl on it and the roller diameter is 1.25" (I thought it was 1.5" when I bought mine but I was wrong). I the Cranksteins are 1.5".

Because of the relatively small diameter of the rollers on the BC(compared to bigger industrial type rollers) they need to have a fairly severe knurl to grab the grain and pull it through because there isn't enough pinch. The spikey nature of the knurl sort of pierces the grain kernels and shatters them, more so than with mills with big diameter rollers that tend to flatten the kernels. So it gives you quite a gritty kind of grist rather than a fluffy powdered grist with flattened husks.

Basically what I'm getting to is that mill gap set on other mills isn't really applicable on the Barley Crusher because you can only measure the gap between the "points" of the knurl. Having never seen a Crankstein in the flesh it does appear from the photos to have a more mild knurl so essentially your rollers are closer together than on the BC when you measure it (if you follow).

Don't get me wrong Chirs, the Barley Crusher is a great mill and I think mine is excellent. It has served me very well. But I think the gap on a BC is something you have to either feel your way for, or take a direct measurement off someone with a BC. The measurements I gave above should get you going to some better efficiency.

Just in conclusion, both the Crankstein and the BC are good mills. Both have their good points. Maybe if I was buying again I might get a Crankstein, but for the complete set up you get with the BC it's hard to go past. I used my stock standard straight out of the box for probably 12 months before I fabricated anything extra for it. The Crank you have to build something for it from the start. But I suspect the Crank my give a slightly better crush. But I'm only speculating here.

Cheers, Justin

 

[TasChris]

Thanks gents, i will have play with a set of feeler gauges over the week end and do a few more trials.

 

[Whistlingjack]

I have a Barley Crusher. The paper work with it says the gap is 0.039 inches, which converts to 0.99 millimetres. I have used it now three times and it seems to be getting a good result.

I use the portable drill on slow speed for the barley, but it complains when I put wheat through, so that is done by hand.

Interested in your wiper to mill connection, Justin. Thanks for the idea.

 

[Zierschy]

Don't forget to check out the other mash paramaters that will effect your efficency.

Assuming that you are already checking your temperature I'd suggest checking your mash pH. Check out Figure 79 from Palmers "How to Brew" for more info:
http://www.howtobrew.com/section3/chapter14-1.html