I received a reply from Brewer's Friend today. They said they have spent some time looking over their formulas, and believe everything to be correct.
They provided their conversion efficiency formula as:
CE = 100 * Plato_measured * (100 - Plato_max) / (Plato_max * (100 - Plato_measured))
Where:
Plato_max = 100 * extract_weight / (volume_liters + extract_weight); (extract weight is measured in KG)
They also noted that they visited the Breiss website, referencing this link:
http://blog.brewingwithbriess.com/understanding-a-malt-analysis/
and stated "optimal moisture between 3-6% because of spoilage & crushing problems with moist grain, but it-is-what-it-is, I didn't see any product offered based upon moisture content."
I'm not too sure what to make of that.
They closed by saying their calculation is based on the amount of extract and pre-boil wort volume, and that I should check my volumes.
I'm glad they finally replied, although I'm somewhat confused by their response. I think I will take their advice and check the volume markings on my kettle for accuracy, but they weren't able to explain why their Brewhouse Efficiency calculator and Brew Session tool output a different result.
The end result seems to be if you use Brewer's Friend to calculate conversion efficiency, you can't compare your result to other brewers using different calculators, and you can't compare results from the Brewer's Friend Brewhouse Efficiency Calculator to their own Brew Session tool.
They provided their conversion efficiency formula as:
CE = 100 * Plato_measured * (100 - Plato_max) / (Plato_max * (100 - Plato_measured))
Where:
Plato_max = 100 * extract_weight / (volume_liters + extract_weight); (extract weight is measured in KG)
They also noted that they visited the Breiss website, referencing this link:
http://blog.brewingwithbriess.com/understanding-a-malt-analysis/
and stated "optimal moisture between 3-6% because of spoilage & crushing problems with moist grain, but it-is-what-it-is, I didn't see any product offered based upon moisture content."
I'm not too sure what to make of that.
They closed by saying their calculation is based on the amount of extract and pre-boil wort volume, and that I should check my volumes.
I'm glad they finally replied, although I'm somewhat confused by their response. I think I will take their advice and check the volume markings on my kettle for accuracy, but they weren't able to explain why their Brewhouse Efficiency calculator and Brew Session tool output a different result.
The end result seems to be if you use Brewer's Friend to calculate conversion efficiency, you can't compare your result to other brewers using different calculators, and you can't compare results from the Brewer's Friend Brewhouse Efficiency Calculator to their own Brew Session tool.