Pre Boil Gravity Fine - Post Boil Gravity Low

[MEPNew2Brew]

I use Beersmith.

I am starting to get my system dialed in so that I can actually predict accurately what my mash results, etc. will be.

My pre-boil gravities have been very close to what Beersmith predicts. But, my post boil gravities have been consitently two to four points low. My pre and post boil volumes are as predicted. So, I am not sure what is happening.

My guess is that I need to fiddle with some of the finer adjustments in the mash profile, such as Cooling Shrinkage or something like that. If I always measure volumes at about room temp., what roll does Cooling Shrinkage Play? Should I just set it to zero?

Any thoughts you think may be helpful will be appreciated.

Thank you.

 

[sudbuster]

Please understand, Beersmith is just a software tool and its results are theoretical. If YOU measured accurately, a 2 to 4 point difference is well within the expected outcome considering all of the parameters. Age of grain, temperature calibrations, mash temps and times, how precisely the volumes are measured, etc, etc.

 

[brewfun]

It sounds like the Loss to Trub & Chiller number may be a little high. This would have the effect or giving you an actual post-boil kettle volume that is a little more than what BeerSmith is predicting.

If the Mash and pre-boil numbers are accurate, this would be the adjustment I'd make.

 

[MEPNew2Brew]

Thank you for the replies.