Please check my calculations.

[Brewtallica]

Hi,
I've been going down the rabbit hole on hop utilization and have found a lot of information on this forum. I'm planning on making the Northernbrewer Bloodthirsty Blood Orange Saison kit next week and wanted to modify the instructions, but could use some opinions on the new schedule. I'm planning on going from a 2.5 gal boil to a 5 gallon boil just because I have the capability. Also, I plan to do a late extract addition along with a shorter boil time due to the increased hop utilization.

Current instructions:
2.5 gal boil (60 min)
.5 lb crystal 20l steeping
6 lb pilsen lme
1 lb wheat dme
.5 oz magnum at 60 min
1 oz tettnang at 5 min.

Using brewer's friend, it calculates a little under 20 IBU.

My modified recipe:
5 gallon boil (20 min boil)
.5 lb crystal 20l steeping
2 lb pilsen lme
.5 oz magnum 20 min
1 oz tettnang 5 min
4 lb pilsen lme F/O
1 lb wheat dme F/O

With this schedule, brewer's friend calculates about 28 IBUs.

Thanks in advance for tips and advice on the shorter boil time with late extract additions.

 

[ncbrewer]

For the last few years there's been a lot of controversy about the effect of boil gravity on hop utilization. (Maybe that's why you're asking the question.) According to J Palmer in an interview with J Blichman, it has been settled, and the traditional formulas are considered to be pretty much correct, if not super accurate (depends on your equipment and other variables). Here is the link: https://youtu.be/2nbp_0oi4Kk

Based on this, you should be able to use the formulas in the software and be fairly close. Also, I recently made similar changes in boil gravity, and I adjusted the hop schedule using the Tinseth formula. The results were just what I was looking for, so I feel fairly confident.

 

[Brewtallica]

Thanks ncbrewer, that's the confirmation I needed. Just wanted to make sure I was going to be in the IBU ballpark of the original recipe.

 

[Brewtallica]

So, in using various calculators (set to tinseth) it's safe to say that a lower starting gravity boil due to the late extract addition will equal higher IBUs. Therefore, I can reduce the boil time from 60 minutes to 20 in order to compensate for the increased IBUs. Does that sound correct?

I suppose I could keep the 60 min boil time and reduce the amount of hops but I'd rather save time.

 

[ncbrewer]

So, in using various calculators (set to tinseth) it's safe to say that a lower starting gravity boil due to the late extract addition will equal higher IBUs. Therefore, I can reduce the boil time from 60 minutes to 20 in order to compensate for the increased IBUs. Does that sound correct?

I suppose I could keep the 60 min boil time and reduce the amount of hops but I'd rather save time.

From the formulas, that should work, but now you're adding another variable into the mix. If it was me, I'd probably go with the 60 minute boil for the first try, and then try shortening the boil for the next batch if the results were good. This is probably over conservative - I try not to change too many things at the same time. Judgement calls are what home brewing is all about.

 

[Brewtallica]

Good advice on not introducing too many variables. I think I'm going to go with the reduced boil time. The kit isn't vary hoppy to begin with and I don't mind if it's light on IBUs. I do plan on getting a test kit and sending a sample off to get it analyzed just to see if the software is accurate. It will be interesting to see if the calculators check out. Definitely going to take a lot of notes on this one.

 

[kh54s10]

Are you trying to go with a full boil? I see 5 gallons for 20 minutes. If so, you will still have to use some top up water if you want 5 gallons into the fermenter - boil off. My rig would boil off more than 1/2 gallon in that time.

 

[Brewtallica]

Yes, I'll be going with a full boil. In the calculators I've been entering 5.5 in the boil size and 5 in the batch size.

 

[Brewtallica]

Just got done with the brew.
5.5 gal boil
Grains steeped @170 for 30 min
2.14 lbs pilsen lme
1/2 oz magnum @60
1 oz tettnang @5
1 lb wheat dme f/o
The rest of the pilsen lme (4lbs) f/o
A cup or two over 5 gallons in the fermenter.
O.G. 1.052 (recipe said 1.053)
Pitched 1 packet of rehydrated Belle Saison at 69F.

The gravity sample tasted light but definite hop presence. I'm still planning on sending a sample off the get the actual IBU number. The cheapest place I found so far is $15. Not a bad investment for an experiment.