Homebrewers Association | AHA Forum

General Category => General Homebrew Discussion => Topic started by: ketch32 on September 28, 2011, 10:36:02 PM

Title: IBU standardization!?!
Post by: ketch32 on September 28, 2011, 10:36:02 PM
Been brewing in San Diego for over 7 years now, and I am a hophead.  I am primarily an IPA and Pale brewer with an emphasis on the hop administration.  More than ever I have been offended by the subjective nature of IBU claims by breweries.  It has become a marketing byline and I don’t understand it.  Claims of over 100 IBUs and even 1000 IBUs have me perplexed, and as a BJCP competition entrant and educated beer drinker  ;D, I am at a loss when I read such nonsense on a bottle, especially when the experience is something much different than what is being claimed.  Sometimes I think, “If that’s 100+ IBU’s my homebrew must be 1,000,000 IBU’s.”  Lovibonds, ABVs, volumes, etc. are all specific, measurable metrics.  According to the definition of IBUs, the scale tops out at 100.  There are ways to calculate your IBU’s.  Why then is it possible to exceed the scale?  Why can’t the IBU information help me decide what beer I want to buy rather than tricking me into some marketing scheme? Maybe if a brewery claimed an ABV of 5% and I find out it’s 10%, or rather the “man” finds out, there may an issue legally, taxing, etc.  But, I think the reason the fluctuation in the IBU standard is that there is no enforcer, and thus the marketers have used it to their advantage, but again, if it really doesn’t educate me as a buyer, and in fact misleads me, then it no longer holds value and is just a gimmick. I don’t believe in gimmicky beers.  My ramblings are done, but hopefully we all can stand up for standardizing some of these “measurable” claims – to help educate buyers, to help educate brewers, and ultimately, to aid in the substantiation of claims of the brewers’ product.
Title: Re: IBU standardization!?!
Post by: liquidbrewing on September 28, 2011, 11:08:02 PM
I agree.  As far as I understand 100+ IBU's is only achievable with hop extract.  Maybe that's how they make their claims.  Like Stone claims Ruination is 100+.  My Beersmith claims the Pliny clone I made, recipe from Zymurgy, was over 200 IBU's!

I understand what you're getting at.  If I'm paying $15 for a 12 oz beer that claims to have 120 IBU's, you kinda want some back up right??  But if the beers good I drink.  Hop utilization is way over my head.  But malt plays a part, so maybe only the high alcohol beers can claim to have such high IBU's.  The hops need the malt to isomerize, or something like that...or is it the Two Hearted clone talking,   ;D I digress..
Title: Re: IBU standardization!?!
Post by: mabrungard on September 29, 2011, 01:25:10 PM
The saturation limit for alpha acids in wort or water is on the order of 85 ppm and the conversion to iso-alpha acid approachs 90 percent of the alpha acids with an extended boil.  An IBU is equal to 1 ppm iso-alpha acid.  So, the maximum IBUs achievable in beer will never approach the exaggerated claims from some brewers.  IBU models such as Rager and Tinseth don't take into account the saturation limit and they will show increasing IBUs with increasing hop and alpha acid addition.  

That premise that the IBUs can exceed about 90 ppm is not factual and has been entirely proven by brewers that take the time to measure the amount of iso-alpha in their beers via lab methods.  I heard Vinny Cilurzo quote that Pliny has only about 80 ppm on the best of conditions and more typically is around 75 ppm.  That is more than enough evidence that the saturation limits I mention above are true and factual in practice.  

Now that saturation limit for alpha acids and iso alpha acids doesn't mean that a brewer and drinker cannot achieve and percieve greater bittering through higher hop additions.  There are other bittering and flavor compounds beside iso-alpha acids (oxidized beta acids are one).  But their bittering effect and perception are far less than iso-alphas.  I think its safe to say that a brewer can't really bitter a beer too far given this limitation for iso-alpha.  

The standard for measuring bitterness is Quinine.  I'd say that it may be possible to add more bittering to beer via an addition of that compound, but I'm not sure if its useful in beer.  I'm betting that its been tried by someone before, but I haven't heard of it.

As a testament to the limitation of bittering in beers, take the case of Double IPAs.  They are typically more balanced than IPAs even though the bittering levels calculated for those brews are typically astronomic.  The level of malt overwhelms the bittering and lends to a more balanced perception.  A true testament to that is that my wife will drink most Double IPAs, but finds most IPAs too bittered for her tastes.  

A new IBU formula is needed that includes the limitation of iso-alpha saturation.
Title: Re: IBU standardization!?!
Post by: hopfenundmalz on September 29, 2011, 01:47:44 PM
Don't believe everything that your programs spit out.  Martin states it correctly that the saturation limit is not taken into account.  What that limit is can be debated, but it is around 90-100 IBU's.  I have never hear a pro talk about a lab measurement of 120 IBUs.

You can get over 100 IBUs in the wort.  Some of that drops out with the trub.  The saturation limit goes down as the pH drops in fermentation, so more drops out.  Some of that sticks to the yeast (more in flocculant strains) so you lose more.  The end result is that your final beer is much less in the IBU level than what the wort started out as.

Title: Re: IBU standardization!?!
Post by: dmtaylor on September 29, 2011, 02:32:19 PM
I agree with Martin and Jeff.  Based on various things I have read (and I read a LOT), in conjunction with my knowledge as a chemical engineer, I agree that it appears impossible to truly get more than about 90-100 IBUs in a finished beer, for the reasons M & J have cited.  Truth be told, determination of true IBUs requires a laboratory test, and the various IBU formulas out there are only estimates giving a theoretical value.  The various IBU formulas don't take the ~90 IBU limit into account, so that is why you see advertisements for 200 IBU beers, etc.  It is certainly false advertising, but what it does tell you is that they most likely used an unusually large buttload of hops in that particular beer, which for some folks, is all they really want to know anyway.  Right?!
Title: Re: IBU standardization!?!
Post by: EHall on September 29, 2011, 02:44:41 PM
It is your responsibility as a consumer to educate yourself! Brewers aren't the only ones with 'gimmicks' and 'false advertising'... The last thing we need is more regulation.. especially around something so trivial as IBUs...
Title: Re: IBU standardization!?!
Post by: tomsawyer on September 29, 2011, 03:19:21 PM
I think the EPA should get involved.  Those dangerous extra acids people are throwing out with their trub are probably getting into the water supply and affecting the development of young children's taste buds.
Title: Re: IBU standardization!?!
Post by: phillamb168 on September 29, 2011, 03:31:03 PM
@tomsawyer I am in absolute agreement with you. We have started a movement in France, "GURHou" - Groupe Unitaire de Résistance au Houblon - http://www.facebook.com/groups/259936794027387/?id=263257673695299

The aim of the group is to educate people about the dangers of hops. Hops are evil!
Title: Re: IBU standardization!?!
Post by: hopfenundmalz on September 29, 2011, 03:39:43 PM
@tomsawyer I am in absolute agreement with you. We have started a movement in France, "GURHou" - Groupe Unitaire de Résistance au Houblon - http://www.facebook.com/groups/259936794027387/?id=263257673695299

The aim of the group is to educate people about the dangers of hops. Hops are evil!

Dr. Charles Bamforth always uses an old English quote about hops being "a vile and pernicious weed".

Title: Re: IBU standardization!?!
Post by: ketch32 on September 29, 2011, 03:40:41 PM
Thank you, gentlemen!  A lot of useful information for the brewer who wants to be educated (me).  I, for one, will never claim that my beer is something that it is not.  I think a lot of the people claiming astronomical IBUs just aren't educated on the subject and are jumping on the IBU marketing bandwagon.  I don't believe we have regulations to police bitterness claims.  I would hope honest, educated brewers would self-regulate, as they do with a lot of the ingredients, processes and claims that are used.  If more brewers and consumers know about this, I would think the trend would decrease.  Cheers!
Title: Re: IBU standardization!?!
Post by: bonjour on September 29, 2011, 05:02:17 PM
There are measured IBU's and calculated IBU's.  I have heard of a brewer changing the formulation of a beer because it's measurement wasn't the calculated value he was stating.

I have on occasion stated that the Calculated "IBU's" were xxx, especially when they are over 100.
Title: Re: IBU standardization!?!
Post by: ynotbrusum on September 29, 2011, 06:19:02 PM
But are the calculated IBU's for a lower IBU beer correct in terms of what a lab would measure it at?  For example, trying to be style compliant in formulating a recipe of, say 20 or 30 IBU's?  Or should it be similarly qualified as merely "calculated"?  Finally, how do most programs operate - I.e. Tinseth or Rager?
Title: Re: IBU standardization!?!
Post by: bonjour on September 29, 2011, 06:21:31 PM
Most programs allow both, actually your choice.  Only one functional at a time.
Title: Re: IBU standardization!?!
Post by: hopfenundmalz on September 29, 2011, 06:22:56 PM
This should help you to see how the numbers are calculated.  Garetz too.
http://www.realbeer.com/hops/FAQ.html

On my system Tinseth is accurate to within a couple percent for up to 65 IBU, based on the beers that were measured.
Title: Re: IBU standardization!?!
Post by: denny on September 29, 2011, 06:50:59 PM
But are the calculated IBU's for a lower IBU beer correct in terms of what a lab would measure it at?  For example, trying to be style compliant in formulating a recipe of, say 20 or 30 IBU's?  Or should it be similarly qualified as merely "calculated"?  Finally, how do most programs operate - I.e. Tinseth or Rager?

I use the Tinseth scale.  I had some beers in the 35 IBU range analyzed and the results were almost exactly what Promash predicted.
Title: Re: IBU standardization!?!
Post by: blatz on September 29, 2011, 07:07:14 PM
Most programs allow both, actually your choice.  Only one functional at a time.

actually, with Beersmith 2, I believe it will show you the calcs for both.

Just sayin'
Title: Re: IBU standardization!?!
Post by: dmtaylor on September 29, 2011, 07:37:03 PM
Tinseth is the only formula that is reasonably accurate.  At least, up to about 90 IBUs, after which point it could calculate 5 billion IBUs but you just ain't getting it in real life.
Title: Re: IBU standardization!?!
Post by: weithman5 on September 29, 2011, 08:29:31 PM
my caveat to this is how to estimate for homegrown hops. i always use the norm aau for the variety, but this could vary year to year. for the most part i stick with tinseth, usually do most of my own math but starting to use programs due to laziness. i rarely consider brewing something heavily hopped that tinseth would be grossly inaccurate,
Title: Re: IBU standardization!?!
Post by: narvin on September 29, 2011, 08:35:29 PM
IBU is also a measure of bitterness, not a measure of hoppiness like many people assume.  You can have the same amount of isomerized alpha acids in two different beers with a drastic difference in hop flavor and aroma based on the amount of beta acids and other compounds.
Title: Re: IBU standardization!?!
Post by: dmtaylor on September 29, 2011, 08:38:03 PM
With homegrown hops, of course, the initial estimate for alpha acid is always a swag.  It's best to brew a style where IBUs don't matter so much.  I always say, you should shoot for a pale ale -- then if it's too bitter, call it IPA, and if not bitter enough, then call it a blonde or amber ale.  After that initial batch, you can refine the alpha acid estimate on subsequent batches based on the taste of the first one or two, so that by the third and fourth batch, your refined estimate is literally within about 0.2 to 0.3 percent of the actual alpha acid, which to me seems close enough.  But we digress......
Title: Re: IBU standardization!?!
Post by: morticaixavier on September 29, 2011, 08:57:09 PM
I think to some extent what IBU has become in the commerical beer world (and to some extent in the homebrew world as well) is a short hand to express how much hops of what level of alpha acid content were used in the brew.

The OP mentioned 1000 IBUs at one point. I assume he is talking about the mikkeller product '1000 IBU' what I will say about that beer is that it is the MOST BITTER BEER i have ever tasted. There may be only 90 IBU there by lab standards and 85 ppm active compound but that beer tastes like what the name says.

Perhaps there is need for another notation aside from 'we used 12 lbs of 14% AA hops in this bottle of beer' because that is clunky. Perhaps we need something more like the scovile heat scale used for peppers. That is a subjective measure of how many squirts of sugar water it takes to calm the feeling of heat in the mouth after chewing a piece of a given pepper.

In the case of scovile there may be an actual relationship between the amount of capsaisin (sp?) in the pepper but it is still inherently a subjective measure as it depends on the subjects threshold for percieving the 'heat' of the pepper.

Similarly, while there may not be a direct relationship between the ppm of iso-alpha and perceived bitterness in a beer there is a very real (subjectivly) experience of much higher level of bitterness in some beers.
Title: Re: IBU standardization!?!
Post by: denny on September 29, 2011, 09:40:27 PM
Get your homegrown hops tested for $35.  They do beer testing, also.

http://hopunion.com/27_HopTesting.cfm?p5=open
Title: Re: IBU standardization!?!
Post by: tygo on September 30, 2011, 12:02:02 AM
Get your homegrown hops tested for $35.  They do beer testing, also.

http://hopunion.com/27_HopTesting.cfm?p5=open

That's a really cool service.  Thanks for posting the link.
Title: Re: IBU standardization!?!
Post by: ketch32 on October 10, 2011, 10:34:52 PM
Awesome info - thank you all for great feedback and education on the subject.  Love how you can get the bittering levels actually verified, which if I was selling my beer and claiming outrageous levels, I could actually back it up.  As a consumer I wish that the claims on a bottle were true and somewhat telling of the product, you know from honest brewers.   I just saw this article that seemed to address this issue and my concern for the IBU standardization, if I say my beer has the highest IBU's of any beer, and thus, you should pay me $45 per bottle, am I telling you the truth, or just trying to get your money for all the hops and/or extract I bought, as well as the lost beer due to all the hop sediment?: http://mybeerbuzz.blogspot.com/2011/06/flying-monkey-claims-highest-ibu-beer.html (http://mybeerbuzz.blogspot.com/2011/06/flying-monkey-claims-highest-ibu-beer.html).

There are alcohol levels stated on beer labels.  There are special ingredients, like ginger, stated on beer labels.  There are even stories about where the water comes from on beer labels.  Do you see any of those type of claims being misrepresented as much as IBU claims?  Education is the key, and again I thank you for helping educate me.

Cheers!

Title: Re: IBU standardization!?!
Post by: hopfenundmalz on October 10, 2011, 11:01:53 PM
The 2500 is in theory, not in practice.  They need to back that up with a lab analysis..  I think they wil not do that.   Emperor and no clothes comes to mind.
Title: Re: IBU standardization!?!
Post by: a10t2 on October 10, 2011, 11:34:51 PM
The IBU is standardized. It's the absorbance of beer that's been mixed with a reagent, measured via a spectrophotometer at a particular wavelength. That's what an IBU is. You can try to correlate the results of the test to the amount of alpha acids added to the wort, but only if you understand the limitations of your correlation. As was said here, one major limitation to IBU estimation is the saturation limits of the iso-alpha acids. So anyone who claims an IBU level above 100 is almost certainly blindly reporting the result of a formula, without understanding its limitations. (Or reporting a value they know to be false.)


If you want to look up the procedures for the assay they're available from the ASBC.

There are alcohol levels stated on beer labels.

Almost all of which are also incorrect, being the result of formulas rather than measurements.
Title: Re: IBU standardization!?!
Post by: Jimmy K on October 11, 2011, 12:55:37 PM
Setting aside calculations vs practical limits, you're also confusing IBU, which is a chemical concentration measure, with bitterness, which is a flavor characteristic. IBU can predict bitterness, but the actual bitterness that you taste depends on other factors - maltiness and residual sugars will decrease perceived bitterness, high alcohol may also decease it, and hop flavor and aroma, while not affecting IBU's, often increase the perception of bitterness on your tongue.

Expecting IBU to be a one-stop measure is like being asked how fast your car is and answering 'red'.
Title: Re: IBU standardization!?!
Post by: dmtaylor on October 11, 2011, 06:22:32 PM
There are alcohol levels stated on beer labels.

Almost all of which are also incorrect, being the result of formulas rather than measurements.

Actually I think the physical properties of alcohol/water mixtures are pretty well known to the point that if you're off by 0.1% ABV, no one's going to fret about that.  And it's not solely based on formulae -- you can easily take OG and FG readings with a hydrometer to confirm theory.  With IBUs, though, not so simple.  Anybody have a photospectrometer just laying around?  ;)
Title: Re: IBU standardization!?!
Post by: morticaixavier on October 11, 2011, 06:59:50 PM
There are alcohol levels stated on beer labels.

Almost all of which are also incorrect, being the result of formulas rather than measurements.

Actually I think the physical properties of alcohol/water mixtures are pretty well known to the point that if you're off by 0.1% ABV, no one's going to fret about that.  And it's not solely based on formulae -- you can easily take OG and FG readings with a hydrometer to confirm theory.  With IBUs, though, not so simple.  Anybody have a photospectrometer just laying around?  ;)

OG less FG is a formula. and not a precise measurement of ABV. You've got other disolved solids, the differential between density of alchahol v water or water sugar.
Title: Re: IBU standardization!?!
Post by: tschmidlin on October 12, 2011, 05:30:32 PM
OG less FG is a formula. and not a precise measurement of ABV. You've got other disolved solids, the differential between density of alchahol v water or water sugar.
More importantly, the reported ABV is what they predict or actually got for a batch or two, then had printed on thousands and thousands of labels with no changes to the label even if the beer drifts or has batch to batch variation.  I'm sure what the mega brewers report is dead on, micros not so much.