BU:GU question - isn't FG more meaningful?

[CraptainWirtz]

Suppose I have two beers. For the sake of argument, assume they have identical grain bills (by %). Beer #1 has OG = 1.075 and FG = 1.010, and 50 IBU, resulting in a BU:GU ratio of 0.67. Beer #2 has OHG = 1.060 and FG = 1.020, and 50 IBU, resulting in a BU:GU ratio of 0.83.

As I understand the BU:GU theory, you might consider Beer #1 to be more balanced and Beer #2 to be more bitter. But given the differences in residual sugar between the two beers, wouldn't it be more meaningful to construct a ratio based on IBU and FG? Wouldn't Beer #1 actually taste more bitter because there's not as much sweetness to balance it out, or am I missing something?

Thanks,
Mark

 

[Cerevisaphile]

I agree, but I think there is more to the balance than OG and FG. It also matters what sugars make up the gravity. I've had beers that were mashed at high temperatures and started in the 1.060s and finished with FGs in the 1.020s that didn't taste sweet. I had a English mild that started at 1.038 and fermentation stopped early at 1.016 because of a temperature drop and it was cloyingly sweet. I think that any ratio we could come up with assumes the beers being compared have similar attenuation, grist composition, etc.

 

[Dragon]

When you say that it may matter what sugars make up the gravity, does that mean two beers may have had the same OG and FG and IBUs but still one is sweeter than the other because of different malts/adjuncts/sugars used?
Also, would mash temperature matter as well (beyond just helping determine FG)?
On a related note: How do ABV play into the flavor profile (in regard to balance and BU:GU)?

 

[GilaMinumBeer]

IIRC, BU:GU is meant to be more of a metric for design balance by style rather than a perceived finish profile. Too many factors come into play at fermentation for the metric to hold merit at the finish line.

Otherwise, I'd expect GU to be based on FG to give a more practical representation of bitterness.

 

[TheZymurgist]

IIRC, BU:GU is meant to be more of a metric for design balance by style rather than a perceived finish profile. Too many factors come into play at fermentation for the metric to hold merit at the finish line.

Otherwise, I'd expect GU to be based on FG to give a more practical representation of bitterness.

Exactly. They're both imperfect since there are other factors that play into perceived sweetness and bitterness. Not every beer with the exact same OG, FG, and IBU will have the same balance. Grain bill, type of yeast, and even the types of hops used can effect the balance, even if the numbers are the same.

I use both ratios as a guideline when formulating recipes, and then adjust from there, depending on how it actually tastes.

 

[KegWrangler]

I am a convert of the "Balance Value" method as discussed on this website.

http://www.tc.umn.edu/~rohw0009/homebrewing/calculator/bvcalc.htm

 

[bbrim]

I think Gordon Strong addressed this in Brewing Better Beer. FG really is a better measure in most circumstances. You've also got to consider whether there are roasted malts that will add bitterness and the types of residual sugars that will be left behind. I like to narrow down my preferred BU:GU ratio for each style because I know all those other considerations will be fairly consistent.
For example, when brewing pale ales I shoot for .95-1 because I use a small FWH addition and then load up the kettle late. This gives some smoothness and lots of hop character, so I know I can push it. Dry stout I target .8. I like it firm but not overwhelming. Most Belgians I go between .5-.6 but I try to avoid super high attenuation. This works for me.
I think setting target BU:GU ratios based on styles is a good way to maintain proper balance even when you try a new recipe.

 

[biochemedic]

All other things being equal...I can tell you from experience that the ratio makes a palpable difference. I generally make my SMaSHes at 1.060 with a 0.75 GU:BU ratio. My FG's are routinely 1.012. On my last one, I undershot my gravity on my last one by nearly 20 points (I blame a $h!tty crush from my new LHBS as the one and only feature that was definitely different in this last brew....) FG was still 1.012, but the resultant change in ratio made the final beer much more like a session IPA in terms of it's bitterness. It was delicious, mind you, but not as much like my prior SMaSHes in terms of balance....

 

[Dragon]

All good information! I think I have a better understanding now, that cleared up a lot.

Thank you!!

 

[markstache]

I am a convert of the "Balance Value" method as discussed on this website.

http://www.tc.umn.edu/~rohw0009/homebrewing/calculator/bvcalc.htm

That page was entirely unclear about what it was calculating, and the claimed linear relationship between BU:GU and BV only appears to hold at 70% apparent attenuation.

I recommend these two pages for a clearer approach:

http://www.madalchemist.com/archives/bittering-units-real-extract-bure-calculator/
http://www.madalchemist.com/archives/relative-bitterness-ratio/