Originally Posted by AZ_IPA
Okay - getting to the point...
Why would you want to lower your mash efficiency?
----Seems like he is worried about tannin extraction...
personally 80-85% is about right for a well tuned system. I'd just roll with it unless I was noticing tannin bitterness.
But the cheapest answer is this -- thin your Mash and use less sparge water. you will still run everything through the mash but you will leave more sugar behind.