Trub Loss and Boil SG / Batch volumes

[GregSalyer]

MaltLicker,

Thanks for the reply.   I agree that the SG of the stuff left behind in the kettle is the same as SG of the wort going to the fermenter. So, if I make a 10 gal batch and tell Beersmith 10 gallons of trub loss then the total batch is 20 gallons and the SG (OG) should be half of one with zero trub loss and a 10 gallon batch.   It doesn’t do that.   It does however change the mash efficiency to 156% so it can hold the OG.  You say to chase the efficiency so I’ll try that but something just seems off to me.
Thanks again,
Rick

I just ran into this. The trub loss is not making any sense to me! I found after a few brews that I needed to increase my trub loss and as expected it increased the amount of water, BUT my SG and Est ABV remained the same without me adding any more grain! Obviously this is not going to be the case! I see no reason my efficiency would increase due to adding more water, but that is what the software does.

More water + Same Sugar = Lower SG & ABV

[Oginme]

Fundamentally, this makes sense.  The software does not work using that logic, however.  The software solves the sugar balance by having the user define the amount of sugar from the grain which makes it into the fermenter (Brew house or total efficiency).  This means that the mash efficiency floats to provide that amount of sugar from the grain bill.  If you make a change in your process losses which impact the amount of sugars that get extracted from the mash, then it is up to the user to recalculate the impact on the brew house efficiency and adjust it accordingly.