Beersmith and hop stand

[Neptune]

I'm just figuring out how to use this software. Working on a recipe and I'm questioning what beersmith is telling me.

I'm targeting a 45.6 IBU for an APA. I'm using cascade and columbus hops. According to the software, I only need to add:

0.24 oz Columbus first wort hop (60 min boil)
0.94 oz Columbus hop stand / whirlpool (60 min)
0.94 oz Cascade hop stand / whirlpool (60 min)

Does this sound right for a 5 gallon batch? I must be doing something wrong.

Here's the grain bill (I told it I was using an 11 gallon pot and I'm doing biab if any of that even matters):
11 lbs 2-row
1 lb flaked wheat
0.25 lb C15
0.25 lb C30

I'm using version 2.2.12

Very confused. I'm new to all of this, and it could well be accurate, but it sure seems like this is not consistent with most of the other recipes I'm seeing around...

 

[Oginme]

BeerSmith assumes a 50% utilization based upon time for whirlpool/hop stand hops as a starting point. This number is changeable based upon your experiences or measured values.

My own experience is around 30% utilization (based upon a 20 minute whirlpool). I know that for my kettle for a 20 liter batch, a 60 minute whirlpool is impractical, as the temperature of the whirlpool will drop below 170F in about 40 minutes (depending upon ambient temperature)>

Really the only way to determine how accurate you think this is would be to brew it as you have it and then adjust the utilization based upon your experience. Unless you want to send out a sample for actual IBU measurement and know what the result would be without the hop stand.

 

[Neptune]

Ok, I see... so I should probably just play with the whirlpool times depending on how fast it's going to cool on me (which would differ quite a bit seasonally for me).

Thanks!

 

[Oginme]

Yup, that is one of the reasons that I settled on 20 minute whirlpool before starting to chill. It gives me some measure of consistency regardless of the time of year.

 

[aangel]

I did an 80 minute whirlpool at 150 in my last brew. You've gotta ignore Beersmith in this case - it said I had 100+IBU and trust me, my IBUs were around the 40s.