Bitter Hops vs. bitter hops

OK, I'm trying to understand hop bitterness "character" better. I'm talking the hops thrown in at the beginning of the boil, NOT the flavor and aroma additions. So let us focus on bittering(60-90 minute) additions.

Given the same IBUs, I'm told some hops are not perceived as bitter (astringent?, harsh?) as others. For example, someone said 1 oz of 10 percent centennial vs. 2 oz of a 5% variety would have different percieved bitterness.

Is this true? Are there bittering hops that are nicer to use as a first addition in this regard? I bought a bunch of Cascades and Centennial for IPAs and APAs, but I'm now wondering if I should use a different hop for the 60 minute addition for a different(nicer?) bitterness.

Right, the "harsh" bitterness varies with cohumulone content, which varies by hop variety and other factors.

One thing you can do to reduce "harsh" bitterness, which I picked up on some brewing podcast where they interviewed a hop expert, is to take out your hops additions 12 hours or so before brewing and let them sit at room temps. The acids causing harsh bitterness tend to degrade faster than the others, so this results in a smoother flavor profile.

AA or alpha acids are the actual compound that does the bittering. Boiling hops isomerizes the alpha acids and creates bitterness in your beer. This bitterness is measure in IBU's or International Bittering Units. Most beer software programs will calculate estimated IBU's based on AA content of the hops and boil time for you. It is not a linear forumla, so its kind of hard to do on paper.

What you are saying has nothing to do with percieved bitterness. Its actual IBU's. You will get more IBU's from a 60 min addition of 5%AA hops than a 60 min addition of 10%AA hops. In the same vein, you would need double the amount of 5% AA hops vs 10%AA hops to get the same IBU's out of a 60 min addition. You will very rarely see a 90 min addition. This is why high AA% hops are commonly referred to as clean bittering hops. Some varieties have AA% in the 13-16 range. You need a fraction of the hops to reach the same IBU's. Less hop material in the boil/beer usually translates into a decrease in vegetal/grassy flavors.

Perceived bitterness is another story. I believe perceived bitterness comes mostly from hop aroma. Unlike bitterness, aroma is not a compound we can measure in beer. Aroma comes mostly from dry hopping, or late hop additions. Boiling drives off the most volatile essential oils. This is also a reason high AA% hops are popular for bittering additions. Since you have less hop material, there is less hop character to boil out. Brewers can then use other varieties to make their flavor and aroma additions without changing the actual bitterness of the beer too much.

Edcculus said:

What you are saying has nothing to do with percieved bitterness. Its actual IBU's. You will get more IBU's from a 60 min addition of 5%AA hops than a 60 min addition of 10%AA hops. In the same vein, you would need double the amount of 5% AA hops vs 10%AA hops to get the same IBU's out of a 60 min addition.

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I am well aware of IBUs, and the calculations of them. I was talking about twice the amount of 5% vs. 10%. Sorry if I wasn't clear on that. But that's NOT what this thread is about. FOR THE SAME IBUs IN A BITTERING ADDITION, IS PERCEIVED BITTERNESS DIFFERENT FOR DIFFERENT HOPS.

Edcculus said:

Perceived bitterness is another story. I believe perceived bitterness comes mostly from hop aroma.

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I don't agree, especially for heavily dry hopped IPAs and APAs. The miniscule amount of aroma from a 60 minute addition will be totally masked by 4 oz in the last couple of minutes and another couple oz. in dry hopping. Besides, one can hold their nose and tell bitterness totally without aroma coming into play.

Doing a little research, there appears a lot of contraversy on bitterness "quality" vs. cohumulone content. Many brewers think using bittering hops with lower cohumulone percentages (like Warrier) makes for a "better quality" bitterness. On the other hand, the hop Research council says:
"Despite the paucity of scientific evidence, cohumulone levels are still used an index for hop quality. Dr. Shellhammer’s lab has examined the influence of cohumulone level on beer bitterness quality and discovered that this factor has relatively minimal impact on bitter quality."

So....

From what ive read in a few places about brewing chemistry IBUs measures the actual bitterness and the math is straightforward. However perceived bitterness is dependent on a lot of things including the make up of beta acids in the hops and sulfates in the beer. I dont have my copy of The Principals of Brewing Science with me so maybe someone else can look it up but I think Fix writes about the perceived harshness of various other chemicals in different hop varieties.

weirdboy said:

One thing you can do to reduce "harsh" bitterness, which I picked up on some brewing podcast where they interviewed a hop expert, is to take out your hops additions 12 hours or so before brewing and let them sit at room temps. The acids causing harsh bitterness tend to degrade faster than the others, so this results in a smoother flavor profile.

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Interesting tip. I was kinda put off by the different smell of some new Centennial leaf hops. It was quite different from the older Centennial Pellet hops I had around, which smelled similar to the new Cascade hops.

The next morning, after the sample of new Centennial had aired out overnight, the odd smell was gone, and it smelled more like the pellet samples.

Seems like I need to buy some gallon jugs to do some experiments with.

Probably not related to harsh bitterness, but it's certainly clear there is alot more to hops than AA.....

k1v1116 said:

From what ive read in a few places about brewing chemistry IBUs measures the actual bitterness and the math is straightforward. However perceived bitterness is dependent on a lot of things including the make up of beta acids in the hops and sulfates in the beer. I dont have my copy of The Principals of Brewing Science with me so maybe someone else can look it up but I think Fix writes about the perceived harshness of various other chemicals in different hop varieties.

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Thanks, great reference!

Edit - And, and you are right, IBU math is simple. For anyone who's interested,
AAU = Weight (oz) x % Alpha Acids (whole number).
IBU = AAU x U x 75 / V, where V is volume of the recipe, U is utilization(time and gravity of wort), and 75 is a metric/english conversion factor. It's only Utilization that is non-linear, a function of time and specific gravity. But when adjusting a recipe for different hop alpha acids, one just adjusts the weight for the same AAU.

ah, reading back to the OP, I see that I misread it. Sorry about that.

I think it might still have to do with using less actual hop material in a high AA hop. Definitely not everything though.

First Wort Hops are also generally perceived as giving a softer bitterness even with the same IBUs.

Like has been said, look at the cohumulone. Take Magnum, for instance. One of the reasons it has become so popular is not just because it's got super high alphas, but because it has super low cohumulone, 24-25 for the German one. Brewers Gold, by comparison is 40-48. Never used that hop myself, but I'd say it's gonna have a much rougher, harsher bittering note. Same with Challenger vs Target. Challenger is dual use, has a great aroma and has a cohumulone of 20 to 25. Great! Target's a bit harsher at 35 to 39.

Depends on what you personally like. A lot of folks like the coarser bittering (not me, I like smoother bittering myself). It's sort of like the thing with hop aroma too. A lot of people love the noble type aroma and flavor, that super clean character. And a lot of us like a lot of Myrcene and that strong American character as with Amarillo, Cascade, Crystal and Simcoe. It's not the same issue at all, but they remind me of each other. Some people like a super clean beer all the way through, some people like it mixed up, and some people enjoy the rough edges.

It sounds like you might find this discussion a couple of us had a few weeks back interesting. Especially the discussion between Palefire and I.

https://www.homebrewtalk.com/f14/bittering-hops-just-ibus-134267/

Also this old basic brewing podcast is linad mind-blowing....Palmer actually says that he "got it wrong" in How To Brew...

March 20, 2008 - What Is an IBU . . . Really?
John Palmer, author of How to Brew, shares information from a conference that challenged his concept of what defines an International Bitterness Unit (IBU).

Click to listen, Mp-3

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Cohumulone is not the be-all and end-all of perceived bitterness. There are many variables in the perception of bitterness, almost none of which can be quantified with numbers.

There are parts of brewing that are still magic, boys, and can only be conquered by experience. Hops chemistry and how it impacts perception is one of them.

Take the first-wort hopping technique, for example. Tasting panels have, over and over again, said that beers treated with FWH have better hops flavor and smoother bitterness than beers with traditional additions. No one has yet identified why that is. We've argued it over and over, but even with all of the impactors we can measure - chemical amounts in the hops, boil time, break vs. no break, vegetative mass, ad infinitum - we simply can't find a numerical reason why people tend to prefer FWH flavor. No one number or series of numbers stands out; it's not like you can say, "Aha! It's the cohumulone!"

Short answer: Read. Read descriptions of different varieties. Hops analysis numbers are pretty much meaningless to homebrewers. Unless you've got the lab equipment to actually measure the AA dissolved in the finished product (I don't), it's a 'ballpark' game with hops numbers.

High-alpha hops tend to have a coarser bitterness than low-alpha varieties, presumably because of higher cohumulone but probably because high relative amounts of one chemical means high amounts of everything else related to flavor. A beer bittered with 10% hops tends to suffer in comparison to a beer bittered with 5% hops in tasting panels.

But it's not about identifying one or two magic numbers that will define everything for us. There is no Theory of Everything with hops. Cohumulone is ONE indicator. Don't let it rule your life.

Regards,

Bob

MattHollingsworth said:

First Wort Hops are also generally perceived as giving a softer bitterness even with the same IBUs.

Like has been said, look at the cohumulone. Take Magnum, for instance. One of the reasons it has become so popular is not just because it's got super high alphas, but because it has super low cohumulone, 24-25 for the German one. Brewers Gold, by comparison is 40-48. Never used that hop myself, but I'd say it's gonna have a much rougher, harsher bittering note. Same with Challenger vs Target. Challenger is dual use, has a great aroma and has a cohumulone of 20 to 25. Great! Target's a bit harsher at 35 to 39.

Depends on what you personally like. A lot of folks like the coarser bittering (not me, I like smoother bittering myself). It's sort of like the thing with hop aroma too. A lot of people love the noble type aroma and flavor, that super clean character. And a lot of us like a lot of Myrcene and that strong American character as with Amarillo, Cascade, Crystal and Simcoe. It's not the same issue at all, but they remind me of each other. Some people like a super clean beer all the way through, some people like it mixed up, and some people enjoy the rough edges.

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FWH is the second area of perceived bitterness I've been looking at. Hop bursting is the third (can you tell I'm a west coast hophead looking for more flavor and aroma?)

Being a science oriented engineer all my life, I'm fascinated by the few tests and lack of understanding in these areas. For example, both of the blind taste tests I've found so far concerning FWH show a statistical very weak to non-existent difference between FWH and regular technique. However, both of these tests were done with a substitution of the 60 minute level, whereas most people here seem to instead sub the FWHops for the 20 minute addition. This should be way more bitter. Yet people swear it's less harsh.

Kind of the same thing for cohumulone. One can't dismiss experiences just because science can't fully explain it (yet).

And of course hop bursting also supposedly gives less harshness for the same calculated IBUs. It certainly gives more hop flavor.

NQ3X said:

Take the first-wort hopping technique, for example. Tasting panels have, over and over again, said that beers treated with FWH have better hops flavor and smoother bitterness than beers with traditional additions.

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Can you point me to any of these? So far, I've drawn a blank on searching out a "statistically significant" tasting test for FWH. (like a blind study performed with sufficient numbers of testers)

Edit: It would appear there are some. The one quoted here, for example:
http://brewery.org/library/1stwort.html

Rich

Fun when you answer your own question, innit? I was going to point to that article.

Bob