Hop calculations wayyy off....why? Help

[hotwatermusic]

In regards to the original question, and in what is certainly a less than perfect solution, I simply adjust the hop utilization in my equipment profile settings on Beersmith. For me 70% is ball park to what I feel matches commercial beers with more trust worthy published BU's. Again simply calibrated to my pallet ( beyond repute, I can assure you). As far as the flavor aspect with late hopping there are tricks with that as well and if that is something you would be interested in hearing from others we would need to know a lot more about your process/equipment.

 

[raysmithtx]

I think you are correct. The standard way of doing things hand-waves away some important factors. We just don't have a complete toolbox yet. Your approach seems smart to me.

Any value we calculate today is surely wrong... but by using the available tools in a consistent manner I hope to be less wrong than if I just winged it. A consistently somewhat wrong approach will still help me produce tasty beer, and make meaningful and predictable changes to recipes when I want to adjust bitterness.

I got started down this rabbit hole when I converted a recipe to nearly all late hop additions and the result was WAY too bitter. Much more so than the original recipe even though Beersmith showed the same IBU's for both recipes. Then I found the referenced webpage and started my investigation on why.

What I found was that if I added 1 oz. of 10% hops and boiled for 5 minutes, the general consensus is that I will be adding about 7 IBU.
But if it takes me 20 minutes to reduce the temperature of the wort down to say 160 degrees then I have added an additional 8 IBU's. So what I thought was a 7 IBU addition becomes a 15 IBU addition. Similar results for all the other hop additions but the later hop additions have the most impact.

Since then I made 2 changes to my brewing process: First I bought a Hydra chiller to get the temps down really fast, plus I put all my hops into a giant bag and as soon as the boil is over I immediately remove all the hops. I then start on my steep/whirlpool hops.

 

[helibrewer]

I am working on an experiment and communicating with a guy who's already working on it, that shows it's the protein level, not the gravity alone, of the wort that makes a difference to utilization.

^^^ This. The IBU's are specific to the equipment used and the recipe in question. Utilization will vary from recipe to recipe even on the same equipment. IBU numbers are a very rough estimate for a place to start, and with papers I have read comparing calculated to laboratory analysis, the calculated generally overstated the lab IBU's......sensory is the only way to dial it in, which will give you a "new" IBU reference for that recipe.

 

[ba-brewer]

Consider this...2 worts of the same gravity, but one has a high % of sugar. In that case the protein content will be vastly different although the gravity is the same.

That situation may be more effected by the final gravity then the starting gravity.
http://www.madalchemist.com/relative_bitterness.html

 

[hotwatermusic]

^^^rubs hands. awaits angry response from Denny^^^

 

[ba-brewer]

^^^rubs hands. awaits angry response from Denny^^^

Wrath of Conn?

I was thinking about a human's perception of the finished product, not from a measurement point of view.

 

[Denny]

That situation may be more effected by the final gravity then the starting gravity.
http://www.madalchemist.com/relative_bitterness.html

We'll see. I'm not fermenting these, just tossing the wort after getting my readings, so there is no FG. The pre and post boil readings will tell the story.

 

[Denny]

Wrath of Conn?

I was thinking about a human's perception of the finished product, not from a measurement point of view.

For what I'm doing, perception doesn't play into it. That's another experiment.

 

[ba-brewer]

For what I'm doing, perception doesn't play into it. That's another experiment.

It was unclear to me that you were referring to the experiment you mentioned earlier when I made the first post. I would like to see the result of both tests side by side to see how they relate. There is something that happens to lagers and wheat beers when they drop clear that makes the flavor and bitterness sharper which seems like higher protein levels may be more perception.

 

[Denny]

It was unclear to me that you were referring to the experiment you mentioned earlier when I made the first post. I would like to see the result of both tests side by side to see how they relate. There is something that happens to lagers and wheat beers when they drop clear that makes the flavor and bitterness sharper which seems like higher protein levels may be more perception.

Possibly, but that's a different experiment.

 

[Schlenkerla]

To the OP,

Consider age of the hops if it's under your bitterness expectation.

Http://www.brewerslog.appspot.com/HopAlphaCalc