I haven't read all of this thread - I'm time poor at the moment and it is quite technical - but I'll get to why I think my question fits this thread at the end. It is about trub loss calculations and BHE, I promise

One thing I have just noticed is that it seems to me that BS2 is including the loss to trub in the shrinkage calculation. For example, in my latest brew, I have the following (measured variables) in BS2

Pre-boil vol 30.48L

Pre-boil gravity 1.051

Post boil volume 27.37L

Boil off 2.8L, evaporation rate 9.3% (note - I changed the est pre-boil vol to 30.17 to get the same post boil volume, in reality it was a boil off of 3.12L and 10.23%, but this doesn't affect my question, as the post boil volume is the same)

Shrinkage 2.47L, 9.01%

Trub loss 0.9L

Final volume (meas batch size) 24L

With my real numbers, I have taken the loss to trub from the post boil volume, then subtracted the shrinkage. So this is 27.37 (post boil) - 0.9 (trub) - 2.46 (shrinkage value) leaving 24 L. This gives me a shrinkage value of 9.31%, not 9.01%.

From this, it seems to me that the trub loss is included in the shrinkage (ie, everything at the end of boil undergoes shrinkage), then it is taken away. Is this how it is supposed to be?

Thinking about it, it probably works with an immersion chiller, but I am using a counter flow chiller, which means that the trub losses remain in the kettle and never undergo shrinkage (ok, maybe a few degrees as the whole thing cools down).

As this influences the set variable (BHE, which I am actually coping with fine and am happy to continue to use), maybe there needs to be some consideration of cooling method in the equipment setup