I'm trying to understand my ingredients better...
I used 6lb of Maris Otter Extract in my currently-not-doing-great batch of Boddignton's clone. My OG was only 1.041. Beersmith tells me that I should have expected 1.046. Now, I might have messed up and steeped my specialty grains wrong, but 5 points seems a lot for so few grains (about 13 oz total). Or did I just screw up somehow, and miss my expected OG? I don't see how though, unless it was to do with a late extract addition (3 lb for 60 min; 3 lb with 15 min left)?
I also read in Papazian's book last night that different extracts can have different amounts of fermentables - some might start low and finish high.
So, it looks like I'm going to get a bit of a wimpy beer. Not too worried about that, but I do want to know if that is what I should have expected, so next time I use this extract, I'll know if I need to up the amount or change the way I do things.
I'm guessing the numbers in Beersmith are wrong - I just made a new entry for it, using the same figures as for a Pale Liquid Extract. The values I had in Beersmith are for a Potential of 1.035 OG and the "Dry Yield Fine Grain number" is currently 75%. If I bring the OG number down to about 1.031, then it looks like my measured OG is close to the predicted.