IBUs vs. °Plato? Why isn't this a thing?

There is a thing called perceived bitterness. For this reason we can not quantify bitterness as it relates to sweetness. Everyone is different. We all lose sensitivity once the bitterness gets above a certain threshold, but it is not something a number could be assigned to.

What you perceive as bitter is personal. The amount of isomerized alpha acid is quantifiable.

Part of the challenge a brewer faces is balancing sweet and bitter. There is the art.

Cheers.

 

IBU is a quantitative measurement of something that loosely relates to perceived bitterness. It's really not accurate to equate the two, but we tend to do exactly that with mental adjustments to account for the mitigating effects of sweetness and Plato (a 100 IBU DIPA can be perceived as a lot less bitter than a 60 IBU Pale, for example). Add to that the fact that there are other sources of bitterness that don't reflect in the IBU number, making it even more perplexing. Experience allows us to take all this in stride. The numbers actually become useful for predicting what's in the bottle, at least with respect to bitterness.

 

That was proposed by Ray Daniels as BU:GU ratio. GU=the OG so a 50 IBU beer at 1.075 would be .66.

Others propose BU and FG as that takes the attention into account.

 

Yeah forgot about that one.

I am admittedly not the most technical brewer.
But does anyone use the BU:GU ratio? I can't ever remember it coming up around here.

 

I use appropriate bu:gu ratios as they apply to styles I have not brewed much.
nothing like a hoppy doppelbock to ruin your brewing experience...

 

I try to maintain a proper BU:GU ratio for a given beer style.

There is a good discussion and list here: http://beersmith.com/blog/2009/09/26/balancing-your-beer-with-the-bitterness-ratio/

Cheers!

 

A few more issues is that calculated IBUs is different than achieved. And the yeast used and water ions change perceived bitterness too.

 

I think of BU:GU ratios as a sanity check, one of the brewing programs I used to use automatically calculated it, so it was easy to think about (of course the math is pretty easy to do in one's head as well).

 

Not to mention carbonation level and serving temperature. Still, IBU calculations and BU/GU calculations are useful. They just don't tell the whole story. I doubt any model ever will. If they did, we could just pop target numbers into our picobrewiematics and call it a day.

 

I think everyone uses it when formulating a recipe without realizing that they are doing so. As far as using the actual numbers, I do use it mostly for hoppy beers. Every hoppy beer that I brew is hopbursted and I typically aim for a 1:1 ratio for IPA's. My IPA at work is an OG of 1.064 and has 62-66 IBU's. My session IPA was 1.044 and was 45 IBU's. Double IPA is 1.25:1 (1.075 and 90 IBU) and Pale Ale is .65:1 (1.060 and 40 IBU)

That said, I know a lot of my friends in the industry don't pay attention at all to late kettle addition IBU's. Some of them will take their desired ratio (normally I see .75-1) and that will all come from their bittering addition. Then they use what ever amount of hops they need late in the boil and dry hop to achieve the intensity of flavor they desire. I know a few people that have tried to come up with Aroma Units for this calculation using the percentage of oil, but I have never thought they would be able to get that consistent, even though some people swear by it.

 

Weedy, did you attend the recent CBC in Philly? If so, did you attend the presentation entitled “Hop Oil & Dry – Hopping” by Daniel Vollmer PhD Candidate Oregon State University?

It was an interesting presentation. The net conclusion was:

“Q: Does hop oil content correlate with hop aroma intensity in a dry - hopped beer?

A: No”

Daniel then went on to state: “Oil Quality over Oil Quantity”

Cheers!

 

Did y

Did you go to CBC? It would have been convenient for you.

 

Jeff, no I didn't. If you are not a Brewers Association member (and I am not) the cost to attend CBC was $1600. Even if I was inclined to pay that amount my wife would have vetoed that from happening.

Cheers!

Jack

 

That has definitely been my experience as well. I did not go since I was preparing for my wedding the following week.

 

I consider it in indirectly during recipe design. For instance, Beersmith shows a graphic that indicates whether bitterness is high or low for style, and gravity is high or low for style, which sort of supplants needing the calculated BU:GU statistic. There was a time where I looked at it more carefully. I have mentioned it in posts assuming it was part of brewers' vocab. Was about to mention it here but was beat to the punch.

 

Congratulations on your marriage!

My wife reminds me regularly that marriage is bliss. And she is indeed correct here!!

Cheers!