I did my second All Grain batch last weekend using the BIAB method with pump driven recirculation. The first batch was a brown ale, and everything went perfect. This batch was a weissen - 50% pils/50% wheat. After mashing for an hour I checked the gravity and was SUPER low. I finally hit my numbers (1.042 pre-boil), but I had to mash for THREE HOURS to get there. I used BeerSmith for the recipe, so I know I had enough grain (18 lbs total for a 10 gal batch).
What went wrong? Could it be the different grain? Perhaps the crush? (I purchased and milled the grain at a different store than my first batch)
I appreciate all feedback!