2 weeks ago I made a cherry wit that used 8 lbs of pils and 7 lbs of wheat for a 10 gallon batch and ended up getting 80% efficiency. Last weekend I made another version of the same beer that used 4 lbs of pils and 4 lbs of wheat for a 5 gallon batch and only got 60% efficiency. Nothing else changed. I had been averaging 80% efficiency except for that batch. I did not add any enzymes because I thought a 50/50 ratio was okay, but I guess I was wrong. Do you think there weren't enough enzymes to convert the starch with a 50/50 mix? I can't think of anything else that would have caused this...