BU/GU vs Perceived Hop Aroma/Flavor

[Jaymex98]

Hop lovers,
I have a question that I have been trying to solve with non-scientific experimentation. No conclusive results...

Does the BU/GU ratio affect perceived hop aroma/flavor?

I have made multiple pale ales (pure Vienna malt) with great success and a BU/GU ratio of .48. For these experiments I only mash at 152’F for 1 hour, use Magnum (60 mins) for bittering and Wyeast 1056 for 5G batches. I have tried the same hop aroma/flavor charge regimen of 5 mins, 0 mins and dry hop at 3/4 attenuation. The hop combos I have tried (1 oz each) are Azacca, Citra, Lemon Drop; Cascade, Azacca, Citra; and Citra, Denali, Cashmere.

All the pale ales have been great...good malt backbone, great hop aroma and flavor. Most importantly, they were not out of balance.

I recently increased the BU/GU ratio with the above recipe to an IPA-like ratio of .84 with the same hop aroma/flavor regimen as described above with Cascade, Azacca and Citra. The hop aroma/flavor is not (edit...nearly as pronounced as in the pale ales)!

By the way, I used the same water profile for all the above beers of “light colored and hoppy” from Brewer’s Friend.

Thanks for the thoughts.
J98

 

[dmtaylor]

This makes no sense at all. You must have some bad hops. BU:GU has nothing to do with hop flavor or aroma, only bitterness.

 

[Oginme]

My personal take on this given some 200+ batches brewed is as follows:

The IBU test is way to measure isomerized alpha acids (and some other compounds which absorb light at 275 nm) from the hops which has been correlated to the perception of bitterness. The perception of bitterness is variable based upon the individual and their own, unique sensitivity to tasting bitter substances. There are many other compounds in the beer that do not show up on an IBU test which also can lead to a perception of bitterness.

The IBU models is a crude way of quantifying what could be in the beer should it be tested. I think there has been enough cross testing now to confirm that the models and their relationship to actual test results is pretty loose. Too much depends upon process to really conclude that any calculation will be accurate with regard to an actual test or more importantly an individual's perception of bitterness in a given beer.

That being said, there is no relationship between an IBU value and the presence of hop flavors and aromas. It is strictly an organoleptic response which also varies from taster to taster. I make an American wheat beer with all whirlpool hops which has extremely high hop flavor and aroma and very low perceptible bitterness. No correlation at all to IBU. The Tinseth model (modified for whirlpool additions -- again a shaky relationship) would have me believe that this is a 22 IBU beer. My tests show up as around 13 IBU. It is loaded and dominated by hop flavors and smells strongly of passion fruit, melon, and orange citrus.

As typical humans, we try to quantify some of these aspects into numbers (or in this case a number) so that we can rationalize them for planning and expectation. Reality, being the bastard that it is, gives us different perceptions based upon so many other variables: our past history of experiences, past exposure to the given aromatic substances we are experiencing, the environment we are in when tasting a beer, our own health at the time of tasting, other items we may be sensing, smelling, tasting at the time we imbibe, etc.

In short, do not rely on numbers to give you guidance on how a beer should turn out with regard to hop aromas and flavors. There are just too many other factors which play into your perceptions of flavor and aroma. Break a recipe down into component parts and additions and learn what the adjustment of a given ingredient will do for flavors, aromas, bitterness in your process. From that understanding, you can make meaningful changes to deliver the beer profile you are expecting.

 

[McKnuckle]

I wouldn't be so quick to dismiss this. The OP has had numerous batches brewed with apparently fixed variables, and is sharing empirical observations. Do we all really know how hop bitterness compounds may interact with other sensory compounds contributing to flavor? I don't think so.

Note that I am not in any way raising my hand to say "yes, I've experienced this too." I just would not cast off the observations as being uninteresting.

I will be experimenting a bit with this myself. I always use BU/GU targets in my recipes.

 

[Jaymex98]

DM, I might be dumb but I am not stupid. The hops for the IPA were only left out for a week...I edited a sentence in the original post for clarity.

OG, nice response. Put another way, I understand no relationship between BG/GU and hop flavor/aroma for planning a recipe. But, does bitterness affect hop flavor/aroma perception?

McK, to be clear, I have made multiple pale ales but only 1 IPA in this fashion.

Thanks
J98

 

[dmtaylor]

DM, I might be dumb but I am not stupid.

I didn't say you were dumb or stupid. I said "This makes no sense at all", which, it doesn't; hence, your post here. I don't dispute that there is some good discussion by others here. I just can't make any sense of it either.

The hops for the IPA were only left out for a week...I edited a sentence in the original post for clarity.

Yeah, when I first responded, your post said something to the effect of: "The hop aroma/flavor is not there at all" -- maybe not the exact words but pretty close. Your new phrasing is quite different. Anyway...... what do you mean by "left out"?? If you left the hops sitting out at room temperature or exposed to oxygen for a week for the IPA version, you'll lose something just from that, which might fully explained what happened. Please clarify your meaning here.

 

[Oginme]

OG, nice response. Put another way, I understand no relationship between BG/GU and hop flavor/aroma for planning a recipe. But, does bitterness affect hop flavor/aroma perception?

Thanks
J98

Good question. I can only answer from my experiences that they may not be decoupled entirely for flavor. An increase in bitterness may impact the lasting impression or disrupt the flavor perception of the hops as the bitterness starts to dominate your organoleptic response.

As for aroma, I can not smell bitterness, so I can see those being somewhat unrelated, other than the choice of materials which gives us the aromas we desire (hops) also contributes to bitterness response. So additions of more hops to increase aroma perception can also increase the bitterness, impacting flavor more than aroma.

 

[BobBailey]

I assume that you increased the BU/GU ratio by increasing the bittering addition. If this is the case, I wonder if the bitterness masked some of the flavor/aroma. Since everyone's palate is different this might affect your perception more than someone else's of visa versa.

 

[Jaymex98]

DM-messing with you. I don’t think the hops were bad. If I left them out of cold storage and exposed to oxygen, then I would agree with you. Yes, I incorrectly stated no hop flavor/aroma in my original and unedited post. But, the situation is more greatly diminished hop flavor and somewhat diminished aroma

OG/Bob-this was more of the discussion I envisioned.

If I made the same exact recipe for the pale ale and the IPA with the only difference being the amount of DE Magnum hops added for bittering, can hop flavor/aroma perception be affected?

If it is, what do you think is the answer to get the same perception of flavor/aroma? If the BU/GU is doubled, do you double the amount of flavor/aroma hops to each charge? Or...if I increase the bittering hops (for example) from 1 oz to 2 oz, do I increase the flavor/aroma addition by 1 oz?

I think the first idea of doubling is more correcter.

Thanks
J98

 

[Oginme]

If I made the same exact recipe for the pale ale and the IPA with the only difference being the amount of DE Magnum hops added for bittering, can hop flavor/aroma perception be affected?

If it is, what do you think is the answer to get the same perception of flavor/aroma? If the BU/GU is doubled, do you double the amount of flavor/aroma hops to each charge? Or...if I increase the bittering hops (for example) from 1 oz to 2 oz, do I increase the flavor/aroma addition by 1 oz?

So going from a PA to an IPA, are you also changing the OG as well? I generally run my IPAs a bit higher in OG and have a corresponding increase in the FG due to that change. This leaves a possibly perceptible change in residual sweetness. I say possibly as I think the ability for a person to differentiate small changes in beers has been shown to be pretty difficult by both the Brulosophy team and the Experimental Brewing testers. It has often been floated that any type of a metric which tries to rank IBU vs gravity for a beer should also include the FG as this leads to a change in perception of the beer.

Going back to your first question here about doubling just the bittering addition, in my thoughts it will make a change in the balance of the end product. Whether that change rises to the level where a taster can determine a difference or not is the question. How much of that change impacts the hop flavor/aroma is another good question and one that only can be determined through brewing and tasting.

The flavors and aromas I get from the bittering additions are very subdued compared to late boil/whirlpool/dry hopping additions. Given that, I would suspect no real change in the flavor and aroma from the actual bitterness imparted, but a possible decrease in hop flavor from competition with the increase in perceptible bitterness.

Edit: But then again, I may just be rationalizing the way I think it should work...

 

[BobBailey]

Either doubling flavor/aroma addition(s) as you suggest or increasing the bittering addition so that it represents the same percentage of the overall IBUs. The latter would be more along the line of scaling which generally works well.

 

[Jaymex98]

The APA and IPA recipes were the same, same OG and FG.