Pre and Post Boil OG's

[MyQul]

Is the OG pre -boil the same as post boil?

Of course post will normally be higher with boil off, but when doing Maxi-BIAB you continually top up the pot with sparge runnings so the volume stay the same.

So if the volume of the wort is exactly the same pre and post boil does the OG stay the same?

 

[Brew_Mike]

No because you are still adding wort to the pot, If you were topping up with water then yes it would

 

[MyQul]

So I take it as I'm adding more wort during the boil to keep the volume up the additional wort is gradually increasing the OG?