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You are here: Home --> Forum Home --> Brewing Forum --> Brewing Discussion --> Hop Utilization

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Matt
Charter Member
Normal, IL
341 Posts


Hey guys!

So, BeerSmith recommends keeping hop utilization at 100%. However, as gravity increases doesn't hop utilization go down? Palmer even discusses it in How to Brew. 

I don't have my paper copy on me right now, but the online version uses Tinseth's model for hop utilization. 

What are your guys thoughts on this? I'm of the opinion of adjusting utliziation for gravity and boil time, but who knows, I'm open to other answers. 

Thoughts?




Posted 34 days ago.

vinpaysdoc
Charter Member
High Point, NC
321 Posts


Something about this just makes me think of Will Ferrell next to a fermentor with a huge ass bucket of hops and Christopher Walken as the brewmaster telling him "Trust me, what this beer needs is MORE HOPS!!!"



Posted 34 days ago.

KidMoxie
Charter Member
San Elijo Hills, CA
405 Posts


This is one of those things that falls into the "don't sweat it" category for me. I think you'll find it's only a handful of IBUs difference and with big beers like that you'll usually be tossing in a bunch of IBUs anyway, so I doubt you'll really even notice.



Posted 34 days ago.

homebrewdad
Charter Member
Birmingham, AL
2480 Posts


lol @ vinpaysdoc... this is perfect.

I agree with KidMoxie.  It's so little difference  that I doubt it's worth fooling with.




Posted 34 days ago.

Matt
Charter Member
Normal, IL
341 Posts


Awesome, thanks for the responses guys. Let me walk you though my math, and someone can tell me I'm an idiot and then I can never worry about it again. 

In BeerSmith, I have a 3 gallon batch of RIS with an OG of 1.111. Right now, there are 2.5 oz of Challenger thrown in @ 60, which is 7.5% AA. That hits 76 IBUs in BeerSmith, unadjusted. 

Now, to do the adjusted math:

76 IBUs = AAU x .135 x 75 / 3

So my target IBUs, AAU is unknown, .114 is the utilization number from How to Brew for a 60 minute addition and an OG of 1.110, 75 is constant, and 3 gallons is my batch size. 

Comes out to 22.5 Alpha Acids needed. Since they are all coming from the 60 minute addition, I can just do that equation. 

22.5 AAU = weight in ounces x 7.5% (AA of Challenger)

So in theory I would need 3 oz of Challenger hops to meet the IBUs.

So, 3 ounces at 60 seems different enough than 2.5 oz to account for it.  

Where did I mess up?

Edit: Math and words.




Posted 34 days ago.
Edited 34 days ago by Matt

Matt
Charter Member
Normal, IL
341 Posts


Annndddd Ray pointed out that BeerSmith does in fact account for this and uses the Tinseth model. 

Now I need to figure out what was up with my numbers. 




Posted 34 days ago.

dave
Fenton, MI
13 Posts


Did you figure it out? I don't think you want to use 1.111 OG in your calculations. You should take the begin-boil SG.  Since you're assuming a sweeter wort in your hand calcs, it reduces utilization, and should explain why you're showing 3oz and beersmith 2.5oz.
 
I don't have the software (I've made my own excel sheet with an optimizer and stuff), so I don't know which gravity reading beersmith uses, but I bet my second post that this is your issue.




Posted 34 days ago.
Edited 34 days ago by dave

Matt
Charter Member
Normal, IL
341 Posts


Oh man. You are absolutely right! Nice catch man! Thanks!



Posted 34 days ago.

droid
Salt Lake City, UT
1 Posts


I have often taken issue with hop utilization in general. Something about it just never matched what I was tasting in my own beers. After looking at Glen Tinseth's page he describes arriving at some constants to match his own empirically derived data. He also suggests adjusting these constants up or down to match your own equipment. Hardly an exact formula but the closest we have without using expensive lab equipment. 

I have reduced hop utilization down to 94% in my own BeerSmith settings to adjust for altitude and my kettle and still feel like the IBUs are lower than what's calculated. I've wanted to find a better formula out there for calculating hop utilization but so far it looks like the Tinseth method has become the standard. 




Posted 34 days ago.

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