Originally Posted by jimbot
I think you have it.
I still think its a lot easier with SG units though.
Probably. We get pretty close to the same numbers. At 75% my method gives 28.5 lbs where as you were getting 29.4lbs. Maybe this is because when I calculate the weight of the water I used 8.3 lbs when I should be using the weight of wort. That would give me ~30lbs needed.
I'll just start brewing and calculate my BH efficiency. That way as long as I calculate the weights the same every time, I should be able to hit my numbers.