Fermentor Batch size vs OG

[yesyves@gmail.com]

Hi

I find that when I target the Fermentor for Batch Size, if I change that number the Boil Size post volume does not change but the FG changes.

It would seem to me that if the Boil Size Post volume does not change, the FG should not change either, the only difference being how much of that wort is left in the kettle.

Thanks !

 

[Yooper]

Hi

I find that when I target the Fermentor for Batch Size, if I change that number the Boil Size post volume does not change but the FG changes.

It would seem to me that if the Boil Size Post volume does not change, the FG should not change either, the only difference being how much of that wort is left in the kettle.

Thanks !

The software assumes that if you have 6 gallons post boil, but 5 in the fermenter, that the other gallons is part of the trub loss and so it is not included in the volume. However, I have not seen the FG change as a result of this. Can you give us a screenshot or a link, so I can investigate that?

 

[yesyves@gmail.com]

Thanks for the answer.

First of all, I completely screwed up my post and title as it is about OG, NOT FG. Sorry ! Probably drank too much beer at some point in my life ...

Here is what I am talking about.

S1 : 25L in Kettle, 1.040 OG
S2 : 25L in Kettle and Fermentor, 1.040 OG
S3 : 25L in Kettle, 21L in Fermentor, 1.048 OG

So one way of saying it is how come the OG changes while going from Kettle to fermentor ? Of course, I can adjust the Brewhouse efficiency to match 1.040 OG, but it will still not follow the post-boil size changes (and vice versa)

S1:

S2:

S3:

 

[Yooper]

Right- because those show different batch sizes. The OG will necessarily be different if you’re using the same exact ingredients but in case have 25 liters in the fermenter (like in the bottom) vs 21 liters.