I motorized my mill and lost about 10% efficiency

I use a Corona mill and used the hand crank for a number of batches, and got pretty good mash efficiency. Somewhere around 85%.

A couple of batches ago, I took off the handle and adapted it for a drill. I can grind the grains much faster, but found the last two batches had mash efficiencies in the high 70s. A drop of about 10%.

I didn't change the settings, I'm suspecting the grain moving thru faster is causing the plates to move apart at their outer diameter and not give me such a fine crush as before.

What is the best thing to do to get back my efficiency. Close down the gap, or run the grain thru a second time. I think running the grain thru a second time may work, as the size of the grain going in the second time is smaller, and therefore will deflect the plates less. Anyone any experience with this?

 

I think I would just hand tighten it up the gap a bit. double crushing on a corona mill sounds like dough balls waiting to happen.

 

Not sure about a Corona mill, as I always hand cranked mine. I do know that you'll get a coarser crush with a roller mill if you run it too fast. I assume that's probably your problem. I agree that tightening it up would be your best bet if you can't slow it down.

 

Interesting, what drill and how fast are you spinning the mill? Don't be so sure your mill gap didn't change, the Chinese wing nuts are horrible, I replaced mine at Ace for like two bucks. I would adjust the mill, there is no reason to mill twice, unless you like work

Also, once adjusted, torque it down tight with a pair of pliers.

 

I don't think it loosened up on me. I've actually been surprised at how well it has stayed set. The wing nut hasn't budged on me (except when I move it to mill something like rye).

I turned the setting bolt a quarter turn on Friday, and slowed down the drill speed. Ended up with 84% mash efficiency. Seemed to have recovered what I lost.

One thing I noticed. Before I adjusted the setting, I could turn the mill by hand (empty, no grain). I'm obviously only using the stub, as the handle has been taken off, so there is no mechanical advantage. After closing the gap (by a quarter turn), I can no longer turn the mill by hand.

 

That's right where mine's set at - just to where i can't turn it with my fingers, and i can just hear the plates touch when I run it empty with the drill.

I was in the 84-86% efficiency range for a long time, and just recently I changed the way i sparged to end up with basically zero "dead space" and my efficiency with the same crush is about 90% now.

A small but noticeable improvement.

 

i don't think that it loosend up or anything, but since things are moving faster, the grain isn't receiving the same surface tension. adjust the setting to compensate

 

Yeah, running the mill too fast can result in a different crush. I take samples throughout milling to make sure things are looking ok.