Does someone have an efficiency formula?

I plugged this into BeerTools

6 gallon boil
5 gallon batch
10lbs Munich Malt
3lbs Midwest Wheat Malt
3oz Cascade 60 minutes

They estimated 1.063 OG at 72%. I got 1.080 at 67 degrees or 1.081.

The way I figured my efficiency last time was by changing the percentage until there estimated OG matched what I got.

Does someone have a formula to make this easier.

I answered me own question.

Efficiency Calculator

Says I got 89%. Not bad for AG #2.

gonna say
#G x ppg(35) /batch size = theoretical 100%

measured og/ theoretical=efficiency

eriktlupus said:

gonna say
#G x ppg(35) /batch size = theoretical 100%

measured og/ theoretical=efficiency

Click to expand...

I don't understand.

13# x 35 / 5g = 91

81/91=89%eff

pounds of grain x 35pointpergallon / batch size = maximun extraction

actual extraction/maximun extraction = extraction efficiency

eriktlupus said:

13# x 35 / 5g = 91

81/91=89%eff

pounds of grain x 35pointpergallon / batch size = maximun extraction

actual extraction/maximun extraction = extraction efficiency

Click to expand...

Did you get the 35 from Palmers chart?

impatient said:

Did you get the 35 from Palmers chart?

Click to expand...

nah, beersmith list the high end for the grains in the ingredients list. most are in the 34-37 range so 35 looked like a good average to use.

eriktlupus said:

nah, beersmith list the high end for the grains in the ingredients list. most are in the 34-37 range so 35 looked like a good average to use.

Click to expand...

Thanks....

I've always calculated my efficiency per-boil. Is there a reason to do it post boil? Would come out the same I suspect anyway.

ths works pre or post its just a linear function of gravity and volume when one goes up the other goes down.

VTBrewer said:

I've always calculated my efficiency per-boil. Is there a reason to do it post boil? Would come out the same I suspect anyway.

Click to expand...

The preboil efficiency tells you how efficient your mash/lauter process is and is helpfull when tweaking your crush and lautering process. A postboil efficiency (if calculated based on the OG and volume in your fermentor) gives you your "brewhouse" efficiency and will be less then your preboil efficency due to losses of volume to trub, absorbed by hops, trapped in vessels or tubes etc.

GT