High-alpha hop, non-bittering flavor issues

[wailingguitar]

A question was posed to me by someone taking a brewing science course; " [why would] ...modern high alpha-acid hop varieties create complications for non-bitterness hop-associated flavors when designing a hop-forward style of beer?"

In other words, what flavor issues NOT related to bittering could occur in a beer made with high-alpha hops?

The only issue I could think of IS bittering related; the relative cohumulone level in many high-alpha hops could create a harsh bitterness… even that is debatable. I called Hopsteiner and spoke to one of the reps, the only thing he could come up with was purely subjective; onion/garlic and sulphur-like flavors are not uncommon in high-alpha hops, but it is a matter of taste.

SO, does anyone have any ideas?

 

[helibrewer]

Are you saying a beer made exclusively with high alpha hops?

 

[wailingguitar]

Are you saying a beer made exclusively with high alpha hops?

Not necessarily, it could be, but wouldn't have to be. I think the assumption is that high alpha hops are being used as, at least, a portion of the late and/or dry hops

 

[helibrewer]

There use to be a distinct difference between bittering and aroma but that is getting muddied a bit...take Mosaic, about 14% alpha but also a great flavor/aroma hop.

I see more of an issue going the other way, bittering with low alpha hops due to 1) increased cost, and 2) much higher polyphenols (more vegetable matter).

 

[wailingguitar]

After digging a while, picking more brains, etc., someone had the idea that it might have something to do with the greater tendency towards oxidation in high alpha hops, possibly leading to isovaleric acid and the cheesy character associated with it. Of course, with today's processing methods for pelletized hops, that should be a non-issue

 

[Talgrath]

Well, one thought jumps to mind, could the push towards high alphas in hops result in less diverse flavors and aromas from hops? I don't think so given that even high alpha hops can have unique and diverse flavors (looking at you, Nelson Sauvin). Could it be possible that health benefits relating to hop consumption are being lost as well as compounds that don't provide alpha acid are bred out of hop varieties? That, I'm not sure about.

 

[Yooper]

Do the higher alpha acid hops being referred to also have higher beta acids? Those would be more susceptible to oxidation, and hence some of those off-flavors, even in pelletized hops. Aging in beta acids does change the flavor, the bittering compounds. Since beta acids don't isomerize the way alpha acids do, that could be what they are talking about?