I've been brewing beer for a long time but I've never tried to calculate my brewhouse efficiency. I used this Brewhouse Efficiency Calculator - Brewer's Friend calculator because it seems like I'm getting a lot higher efficiency than the 75% that I have always heard is considered good. I've been using a refractometer not a hydrometer but, I have made sure to calibrate it before taking readings. My efficiency by this calculator, is 96.something! That's rather hard to believe. If it's true, great but, maybe I did something wrong. Can you guys look it over and tell me if everything's okay?