Do I Need A New Mill?

[Mike B1190]

Hi All,

I acquired a grain mill a few years ago. I don't brew all that often so I've probably only made a dozen batches or so with it. It's a Millars Mill. It's a two roller mill and I operate it with a drill.

Anyway, when I first got the mill I tried setting the gap with feeler gauges as recommended by many. I want to say that I started somewhere near .030 and the crush was pretty coarse and didn't look much better than my LHBS. So after some trial and error I ended up adjusting the gap as close as possible. Not sure what it is, but I can't get a credit card through it. It's probably close to the width of a playing card. But what's weird is that the crush still seems pretty course to me and a lot of kernels are somehow making it through that small gap completely unbroken. It seems to be better if I mill by hand, but I'm lazy, so the drill is always there on standby.

I'm not sure what the issue is. Is it operator error? Is there such as thing as having the gap too tight to mill properly? Could it just be the mill itself - bad knurling, rollers not hardened enough, or maybe the chassis of the mill is flexing during operation and the gap wont stay constant?

My efficiency isn't horrible. I'm usually between 72 - 74%, but it hasn't led to huge gains in efficiency like so many seem to report when they get their own mill. The only time I've had efficiency over 75% was one time that I milled twice for a BIAB batch. I typically batch sparge in a cooler.

Anyway, I've been considering a new mill, but thought I would see if anyone might have some insight into a potential fix for this. Yeah, I guess I could just mill twice, but I'm not sure how that would effect lautering in my cooler.

 

[MaxStout]

Maybe the knurling is worn. Or, roller speed might be a factor. Roughly what RPM are you turning it?

 

[Mike B1190]

I honestly couldn't tell you. My drill is a cheap harbor freight corded drill. I think it's 2000 RPMs at top speed, maybe 3000. Not sure what that translates to for the rollers. The drill doesn't have the torque to run any slower than all the way open. I've tried just squeezing the trigger halfway and 3/4 and the mill just gets bound. So, it's faster than ideal, I'm sure.

 

[MaxStout]

Slower is better. Getting the speed down to around 200 RPM is ideal.

 

[Mike B1190]

Slower does seem to do a better job but even when I've hand cranked, I wouldn't call the difference drastic. So, I'm not sure if speed is the main antagonist. Either way, I might have to look into gearing down the drill. I'm not really in a position to motorize it right now.

 

[hotbeer]

What is it that bothers you? You typically want the hull to stay as whole as possible and the kernel to be crushed as completely as possible.

Or is there some wrong thinking in that?

 

[bracconiere]

is the gap even on both sides of the rollers? i had a problem with my JSP Malt Mill, and i had to brace the plates, so that the gap would stay even.....


(if your drill doesn't have the torque, try using a hopper that feeds the malt, slowly in the middle of the rollers?)

 

[day_trippr]

If there are uncrushed grains with that tight a gap I'd assume grains are taking a shortcut through the mill somehow and avoiding the roller gap entirely. I'd suspect spinning it at 2K+ rpms might have something to do with that phenomenon...

Cheers!

 

[Mike B1190]

is the gap even on both sides of the rollers? i had a problem with my JSP Malt Mill, and i had to brace the plates, so that the gap would stay even.....


(if your drill doesn't have the torque, try using a hopper that feeds the malt, slowly in the middle of the rollers?)

It's seems pretty even. Can you explain what you mean by brace the plates? I'm not sure if I follow? The mill has screws to lock the roller after you adjust it. I always make sure those are tight before crushing though.

If there are uncrushed grains with that tight a gap I'd assume grains are taking a shortcut through the mill somehow and avoiding the roller gap entirely. I'd suspect spinning it at 2K+ rpms might have something to do with that phenomenon...

Cheers!

Ill have to keep an eye out for this. Like I said though, even hand cranking doesn't make a massive difference. Any thoughts on how to stop that from happening aside from slowing down?

I might be crazy, but I feel like I've watched grains pass right between the rollers and not even get cracked.

 

[Romex2121]

Kinda wondering how you braced the plates as-well , my mill always has a hard time keeping an even setting from side to side, set one side and it’ll throw off the other side every time ...

 

[Mark3885]

The hopper on my barley crusher drops the grain into the rollers easily a 1/2” away from the roller ends. The hopper comes to within a 1/4” of the rollers so there is no way whole kernels can bypass the gap. I think this might be where your problem is , post a pic of your mill.

 

[bwible]

I have a variable speed corded drill. I barely squeeze the trigger as little as I have to so it turns. I also stop and start many times so it is not running at high speed. Slow is better.