Milling once, milling twice.

In my most recent batch, in an effort to improve mash efficiency, I ran 50% of my grain bill through the mill twice. Seemed a simple enough trick. And seems to have worked; I hit my numbers.

Aside from a possible stuck sparge (didn't happen) am I risking anything else (i.e. extracting tannins or other non-desireables)?

I have a non-adjustable 2-roller mill and use a Gott-style 10 gal cooler MLT with a braided steel O-ring manifold.

I think it would be fine as long as there isn't excessive flour.

What's your gap set to?  I set my mill to .037 inches for 2-row and .030 for wheat.  I've gone as low as .035 for 2-row and no issues with tannins.

Mark

It might not be a bad idea to keep some rice hulls on hand in case you gum up the sparge.

I have been grinding my grain twice at .037 and so far have not had an issue with a stuck sparge. I do a modified fly sparge. I started grinding twice because I have a Millars Mill grinder and at first I was getting a lot of uncrushed grain after milling, so I started running it twice. Had no issues with the double grind so I continue to do it.

I think my plan now is to continue milling an increasing percentage of my grain bill twice at .037 until the sparge sticks, then back off. And keeping rice hulls on hand sounds like a good idea, @Maine. Thanks!