A friend and I just did our second "ALL" grain on Saturday. On both batches we were shooting for a 1.075ish gravity. I don't have the data for the first batch in front of me but we got 76% eff. but missed the gravity because the wort was too diluted. We mashed with 1.0 qt/lb and fly sparged with 2qt/lb but spent so much time recirculating, that we let out sparg water cool down and was only able to raise the grain bed temp to 160. (and forgot to take a grav reading on the first runnings) The second batch was a porter and shot for about the same gravity. This batch we mashed with 1.2qt/lb and came up with 84% conversion eff. according to the first runnings. We knew that we would not be able to boil off the ammount of water that we needed. so descided to sparge with less water. This time the sparge water was the correct temperature but the thermometer probe that was in the grain bed didn't budge over 165. Not sure why but I think maybe there wasn't a uniform flow of water throughout the bed, thus not allowing the probe to warm. The Brewhouse eff. on the second batch was 60% according to beersmith. So if I am going to make a high grav beer am i just going to have to bite the bullet and use a bigger grain bill?
edit: on the second beer we ran off to quickly...probably part of the problem