Hello BF,
This topic has been raised a few times, so I thought I would present the problem in a simple way. The PBG represents the total amount of sugar at the start of the boil. When boiled, the wort has the same amount of sugar, but in a smaller volume. That volume should be the ending kettle volume regardless of how you calculate brew house efficiency. (Of course, there are additional calculations for late additions, but this is the simplest case.) Therefore:
PBG*starting boil volume/ending boil volume = OG
Or
OG*ending boil volume/starting boil volume = PBG
where the specific gravity observations are SG-1. It's even easier to do the math in your head if you then multiply by 1000 so SG of 1.050 becomes 50.
My only other thought is that PBG is irrelevant in a recipe -- it only becomes important on brew day.
It would be great if this could be fixed. Thanks, PZ
This topic has been raised a few times, so I thought I would present the problem in a simple way. The PBG represents the total amount of sugar at the start of the boil. When boiled, the wort has the same amount of sugar, but in a smaller volume. That volume should be the ending kettle volume regardless of how you calculate brew house efficiency. (Of course, there are additional calculations for late additions, but this is the simplest case.) Therefore:
PBG*starting boil volume/ending boil volume = OG
Or
OG*ending boil volume/starting boil volume = PBG
where the specific gravity observations are SG-1. It's even easier to do the math in your head if you then multiply by 1000 so SG of 1.050 becomes 50.
My only other thought is that PBG is irrelevant in a recipe -- it only becomes important on brew day.
It would be great if this could be fixed. Thanks, PZ
.
