I'm tracking down some discrepancies we're seeing with pre & post-boil gravities here at the brewery. It appears that BS2 isn't handling pre-boil gravity correctly.
Attached is a 1 gallon "recipe" with 1 lb of sugar. There is no boil-off, trub loss, or cooling shrinkage so pre-boil volume equals batch size. Efficiencies & yields are at 100%. As expected, OG is 1.046 and pre-boil gravity is 1.046. If I change trub loss to 1 gallon pre-boil volume correctly changes to 2 gallons and OG drops by half to 1.023. However, pre-boil gravity does not change. It should also be 1.023 because we are still dissolving 1 lb of sugar in 2 gal of water.
How does BS2 derive pre-boil gravity?
Attached is a 1 gallon "recipe" with 1 lb of sugar. There is no boil-off, trub loss, or cooling shrinkage so pre-boil volume equals batch size. Efficiencies & yields are at 100%. As expected, OG is 1.046 and pre-boil gravity is 1.046. If I change trub loss to 1 gallon pre-boil volume correctly changes to 2 gallons and OG drops by half to 1.023. However, pre-boil gravity does not change. It should also be 1.023 because we are still dissolving 1 lb of sugar in 2 gal of water.
How does BS2 derive pre-boil gravity?