Thanks for the reply. I BIAB, so the two figures should be the same for me. http://www.brewersfriend.com/brewhouse-efficiency/ describes your picture with words, yet I still do not see where my 5% is going.

For some reason there seems to be a ~5% efficiency deduction between mash efficiency and preboil. Why does this happen? In this example, I completed my mash with 28L of wort at 1.040. I get 83.6% conversion efficiency. My preboil efficiency with the same 28L and 1.040 only has 78%. Where did I...

+1 I love having cloud storage, but cant completely trust it. Ive been burnt too many times before.