Well if you're batch sparging you just wasted time. That's the really.nice thing about batch sparging, its really fast. You draining slowly definitely didn't cause you're og problem. You'd have to explain your process and whether or not you crushed your own grains etc.
Thanks for the quick reply. I did crush my own grain at my LHBS. I have crushed all my grain there for previous batches, but he has been having mill issues lately, so I think the spacing may have changed (I noticed that there was not as much grain dust as in the past).
Here is what I did...
Mash (10gal Igloo MLT)
260oz grain
1. Pre-heated the MLT, then added 5gal @ 167F to the grain; stirred well (no dough balls)
2. 30 min into the mash, stirred again, checked temp - 158F
3. 60 min end of mash, stirred, checked temp - 158F (I didn't lose as much heat as I have in the past, so it was a higher than my target of 152F)
4. Drained mash till empty over period of ~20min
5. Added my sparge water - 3.6gal @ 170F (prob should have been hotter to bring the grain bed back up to temp)
6. Stirred and let sit for 5 min (again, prob should have been longer)
7. Drained mash till empty over period of ~10 min
8. Ended up with a little more wort than my recipe said I would (~.3gal more)
I partially cover my boils so I don't lose as much to evaporation, but my ending post boil was on target.
The remaining portions of the recipe went as planned. I did not test the mash out gravity. I only tested after the boil as usual. I'm just shocked that I was significantly off...not just a few points.
I know that without seeing my process, equipment, grain crush size, etc.; identifying the source of my problem is difficult. Though, any advice that could help me to not reproduce this problem would be appreciated.
Thanks.