Reduce IBUs but Maintain Hop Ratio

[jerryalan]

Good evening! I'm taking a recipe I created and reducing the estimated OG from 1.077 to 1.059 and reducing the IBUs from 77 to 65. My hop schedule is as follows:

1.2 oz Centennial [10.0%] - 60 min
0.25 oz Chinook [13.0%] - 60 min
0.6 oz Centennial [10.0%] - 30 min
0.5 oz Cascade [5.5%] - 30 min
0.6 oz Williamette [5.5%] - 15 min
0.6 oz Centennial [10.0%] - 15 min
0.6 oz Centennial [10.0%] - flame-out
1 oz Centennial [10.0%] - dry hopped

The reason for this hop schedule is that I brewed an APA and a strong IIPA. I did a 50/50 blend and it tasted great so I'm trying to replicate that. The hop schedule is simply half of each hop used. When I reduced the grain bill to get to my new OG the IBUs went up to 87 due to improved hop utilization in the less concentrated wort.

I'm not sure which hops to reduce and by how much to get the IBUs down to 65 while retaining the same flavor profile. Do I just reduce the bittering hops and leave the rest to retain the flavor and aromas?

 

[MalFet]

The role of gravity in hop extraction is actually quite poorly understood, so I wouldn't rely on the formulas for much more than a vague guide. Unfortunately, that means you'll need to do some experimentation to find the right balance. Personally, I'd start by cutting hops by 10% or so across the board, not just bittering.

 

[jkarp]

I agree some trial and error is in order but I'd probably start by leaving everything at 15 and below alone and dial back those 30 and 60 additions.

 

[jerryalan]

Thanks for the advice guys! I was hoping I could use some cool calculation for this but I'll have more fun experimenting