Originally Posted by DeadYetiBrew
Buying or obtaining a copy of a brewing program is very beneficial.
I'm all for brewing software to make your brew day less stressful, but there is something to be said for learning the math behind the brewing process too....
efficiency would be calculated by taking the total gravity points you got (240 pts in jeepmarine's case) and dividing it by the how many gravity points if you had perfect (100%) efficiency and multiplying by 100. For this, you need to the the "theoretical max points" for your grains. You can find tables on them on the internets...
For Edworts 5 gallon batch:
8lbs 2-row @36pts/lb = 288pts
2lbs Vienna @ 35pts/lb = 70pts
0.5lb of Crystal 10L @ 34 pts/lb = 17pts
total 375pts. (288+70+17)...in other words, if had a perfect mash and sparge where you converted 100% of starches to sugars and then rinsed the grain bed of that sugar perfecting you would have 375pts.
so for jeepmarine: 240/375*100 = 64% efficiency