Brewfather partial mash, water calculation seems incorrect

[hungupdown]

Did Award Imperial Stout, partial mash recipe, earlier this week, total gravity 1134 (target 14.3% with dextrose additions).
Went with Brewfather figures, but then ended up having to boil more than twice as long as specified, to get correct final volume. It's looking like Brewfather isn't taking account of the LME volume (LME was included in Fermentables).

Recipe: batch volume 20L; boil time 60min; 3kg LME added at flameout.

Brewfather gave boil volume 26.38L. Equipment profile: boil off 4.5L/hour; trub/Chiller loss 1L; mash tun loss 0L.
After boil that should give 26.38 - 4.5 -1L = 20.88L, which is 0.8L over batch volume.

But adding 3kg LME at flameout, which (at 1.2kg/L) is 2.5L, would give 23.88L, or 3.88L over batch volume.

I actually boiled to around 18L, giving 20.5L after LME addition (as I find I'm getting a trub/Chiller loss, of more like 0.5L).

So wondering if there's some other Brewfather setting. I need to get a correct calculation?

 

[Stikius]

Haven't used LME with Brewfather so can't really say anything about calculations, but did you let it know you added the LME at flameout or did you just use default?

 

[hungupdown]

Haven't used LME with Brewfather so can't really say anything about calculations, but did you let it know you added the LME at flameout or did you just use default?

Thanks.
Did specify flameout.
Not sure what the 'default' for LME is, and think brewfather should display "default" plus what the default is, or abandon the 'default' setting.
I've found default's not always what I'd expect. Having to try the options, just to find what matches 'default' is a pain.

 

[Stikius]

Thanks.
Did specify flameout.
Not sure what the 'default' for LME is, and think brewfather should display "default" plus what the default is, or abandon the 'default' setting.
I've found default's not always what I'd expect. Having to try the options, just to find what matches 'default' is a pain.
View attachment 839848

I've actually noticed that default for grain is 60 min mash, so if I have a 60 min mash + 10 min mash out brewfather want me to add the grains 10 min into the mash. If I change from "default" to "mash" I'm told to add them from the beginning of the mash...

 

[hungupdown]

I'll try joining the brewfather FB group, and asking there.