Help with Brewhouse Efficiency

[Cookiedds]

Well then I'm at a loss. As stated before, at least one of your 4 measurements is off (7.5, 6.1, 1.057, 1.079), because the math doesn't compute. I think it's up to you to figure out which one/ones, because I have no idea from you've told us.

Edit:
I had a thought. Were your first runnings (higher SG) mixed well with your sparge runnings (lower SG) before you pulled the first sample? As many people have found out doing a partial boil with extract and then topping off with water, it takes a lot to thoroughly combine the two liquids of different densities. Your first sample may have been mostly sparge runnings, which would throw off your reading.

Excellent point, next batch I will make sure they are thoroughly mixed.