Today I got reacquainted with brewing! My friend and I brewed a Belgian dubbel and we were pretty excited. The wort ran pretty clear after a bit of recycling, and everything looked and smelled great during the whole process. We ended up stopping the sparge when the runnings were at 1.010, and our post-boil OG was 1.080.
Then I got home and put these figures into promash, and i was a little disappointed to see that the system efficiency turned out to be about 66%. For 12.89 lbs of grain plus 2 lbs of belgian candy sugar, they predicted 1.088 OG for 75% efficiency. I'm not sure what I could do to improve this figure. We treated all of our water with 5.2 stabilizer. Our mash was fairly thin at 1.25 quarts per gallon, and we mashed out slightly low at 164 degrees. It was hard to keep the sparge temperature up high enough when we had to recycle the stuff for a while, but most of our wart volume was the water in the mash, anyway.
We finished up by using pure O2 and by pitching a yeast starter. 3 hours later, we had very slow bubbling, but from what I understand, that's fairly quick activity.
Any tips/pointers for the future for better efficiency?