Does dry hopping add bitterness?

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brewdjoffe

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I know that this topic has been covered in the past but I'd like to reopen the discussion.

The last couple of brews I've done have been AIPAs. Generally I'll use a small amount of hops (15/30g) as a bittering addition at 30 mins, and then use quite a lot of whirlpool hops (around 100g) at flameout. The hops have differed in variety but I'm mainly sticking to Columbus, Centennial, Simcoe, Citra and Mosaic.

After about 10 days or so when I take a sample of the beer it tastes great and there isn't too much bitterness on the backend. I know that this probably isn't an exact representation of what the beer will taste like once it has conditioned in the bottle.

Then I dry hop. Again I'll generally use 60/90gm in the dry hop with mainly Simcoe, Mosaic, Citra (depending on recipe). I'll leave the hops in there for 3/4 days in a hop bag. When I take my final sample before bottling there is MUCH more bitterness than the previous sample and this stays all the way through bottling.

I appreciate that AIPAs are supposed to be bitter but I'm looking to create something on the lower end of the IBU spectrum to let the flavour of the hops shine through.

Does anyone have any suggestions?
 

Bribie G

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I'm convinced that dry hopping does add bitterness, especially if you are chucking in a whole foil of very bitter hops such as Citra. When I intend to dry hop I always add my bittering for 30 mins.

Chew a hop pellet and see:

Edit: this is something that I'm interested in, my fave APA is Four Pines Pale Ale which is basically the only Aussie craft beer I'm prepared to chuck out $20 a six pack for, and love the upfront / aroma hops. Maybe you could send a grovelling email to a couple of crafties and see if they have any hints?

gurning.jpg
 

MHB

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Absolutely not, dry hoping can't add any bitterness because Alpha Acids are practically insoluble in "cold" (say under 60oC) water/wort/beer and don't become soluble until isomerised by boiling (or at least being hot for a long time).

I suspect that a lot of home brewers cant tell the difference between Bitterness and Hop Taste. Quite a lot of hop taste can be extracted when dry hopping, it just isn't really bitterness.
If you put some hops in a bit of water and boil them for an hour, add the same amount of hops to tap water and leave them to soak overnight at air temperature, taste the two side by side at the same temperature, one will be bitter the other has hop taste
Might help you to differentiate between the two.
Mark
 

manticle

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It can't add IBU through isomerised alpha but there are other compounds in hops that provide bitter taste. Try your experiment above Mark and I reckon you'll discern bitterness in addition to hop flavour. Yes the boiled one will be more bitter but bitterness will be present in both.
When you chew a hop pellet, that bitterness isn't isomerised, dissolved alpha acid either but it's distinct.
 

Droopy Brew

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Agree with Manticle. It doesn't add IBUs but to my taste buds there is definitely a more perceived bitterness with heavy dry hopping.
 

drsmurto

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GalBrew said:
So dry hopping and bitterness is not as simple as previously thought. Apparently oxidised humulinones are approximately 66% as bitter as isomerised AAs, so dry hopping can add bitterness to your beer (sometimes anyhow). Here is a link for more details:
http://scottjanish.com/increasing-bitterness-dry-hopping/
From a quick perusal of that blog link, I can't see in the final experiment where he has done a control. There is a final IBU concentration post dry hopping but where is the IBU of the base beer without dry hopping? If so, the result is meaningless.
 

GalBrew

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This is a better post than the previous link. The referencing is horrible and I don't have the inclination to trawl through the entire bibliography, but there does seem to be evidence that dry hopping can add bitterness to a beer through humulinones. I've included a couple of papers from hopsteiner but it's not the whole story:

http://scottjanish.com/dry-hopping-effect-bitterness-ibu-testing/

http://www.hopsteiner.de/fileadmin/redeakteur/pdf/neuigkeiten-berichte/technische-veroeffentlichungen_NEU/2016/Humulinone_Formation_in_Hops_and_Hop_Pellets_and_Its_Implications_for_Dry_Hopped_Beers__J.Maye__R.Smith__J._Leker__-_MBAA_2016.pdf

https://hopsteiner.com/wp-content/uploads/2016/09/TQ-53-3-0808-01.pdf
 

Bribie G

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Although his own experiment is dodgy, the literature he refers to suggests that:

"So translating this to a homebrew 5 gallon batch terminology, when the low 8.6 IBU beer was dry hopped with 142 grams of centennial there was a net increase in IBUs of 18.5 IBUs!"

This seems to be similar to the OP's dry hopping schedule.
 

pat_00

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I heavily dry hopped a beer with galaxy and it definitely increased the bitterness. Haven't had this issue with other high AA hops.
 

MHB

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Someone should look up the definition of IBU's, it has little to do with "taste" but is rather a measured quantity, like Colour or SG.

An International Bitterness Unit (IBU) is a measure of the bitterness in beer. One IBU is equal to one milligram of isomerized alpha acid per liter of beer. Isomerized alpha acids are the main bittering acids derived from hops.

Even a quick read of Wikipedia will help with an understanding of the subject.
Mark
 

manticle

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That's exactly my point - IBU (or BU) is measuring isomerised alpha acid. Quantifiable. So - there are other components in hops that provide a bitter sensation. Tonic water is bitter but not due to isomerised alpha acid for example.

Note the term 'main' from your sentence above (as opposed to 'sole'' or ''only''). There are compounds in hops, apart from isomerised alpha acids that contribute a bitter sensation to beer (or water if you want to go back to your steeping experiment).
 

Droopy Brew

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MHB said:
Someone should look up the definition of IBU's, it has little to do with "taste" but is rather a measured quantity, like Colour or SG.

An International Bitterness Unit (IBU) is a measure of the bitterness in beer. One IBU is equal to one milligram of isomerized alpha acid per liter of beer. Isomerized alpha acids are the main bittering acids derived from hops.

Even a quick read of Wikipedia will help with an understanding of the subject.
Mark
That's why I like the term percieived bitterness.
My olfactory system tells me it is more bitter therefore as the consumer of the beer it is more bitter.
However that does not mean there are more IBUs.

Same with smooth vs harsh bitterness. The IBUs may be the same for a beer hopped with say Saaz at 60 minutes and one hopped with Galaxy at 60 minutes but a blind testing will have close on 100% of tasters tell you the Galaxy beer tastes (or is perceived as) more bitter -cohumulones at work.
 

Droopy Brew

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To answer the second of the OPs questions. If you are chasing a smoother bitterness or even lower IBUs with a pronounced hop profile, try using a first wort hop for about 1/3 of your intended IBUS and the rest of the IBUs at whirlpool. Dont forget to use software that accounts for IBUs at whirlpool as some of them count it as 0 which is not the case.
Also look for hops with a low cohumulone content (sub 35%). Higher cohumulone hops tend to add a harsh bitterness if used early in the boil eg Galaxy.

Using the above schedule (I usually chuck a few in at 10 minutes too) you should get plenty of flavour and aroma without the need to dry hop.
 

GalBrew

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So if you read he papers you will find that dry hopping can increase the measured IBU of a beer (compare the control and control + 1lb/bbl cascade dry hop results). Not only that but the extracted hop fraction analysed for IBU contains a whole bunch of stuff other than isomerised AA. Humulinones are one of the compounds that contribute to bitterness and measured IBU, although the authors state that IBU is
an inaccurate measure of bitterness in heavily dry hopped beers due to the various bitter compounds in the beer and their differing affects on the bitterness profile and that is why they advocate the use of HPLC.
 

manticle

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GalBrew said:
So if you read he papers you will find that dry hopping can increase the measured IBU of a beer (compare the control and control + 1lb/bbl cascade dry hop results). Not only that but the extracted hop fraction analysed for IBU contains a whole bunch of stuff other than isomerised AA. Humulinones are one of the compounds that contribute to bitterness and measured IBU, although the authors state that IBU is
an inaccurate measure of bitterness in heavily dry hopped beers due to the various bitter compounds in the beer and their differing affects on the bitterness profile and that is why they advocate the use of HPLC.
Haven't read your linked paper yet but I did read an article somewhere recently (possibly BYO) that suggested similar.
 

citizensnips

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Yes it increases bitterness.
Where's my peer reviewed journal you may ask......my palate. Time and time again I brew double batches and dry hop one 1 of 2 kegs just for fun and just to learn a little more about hop variety, quantities, time, temperature and of course aroma and flavour. Every time however the dry hop beer comes out as being perceived as having more bitterness. As manticle mentioned however, whether that directly attributes to how we quantify bitterness in beer....who knows. All I know is it ends up altering our perception of the beer and can therefore lead to balance issues, meaning it becomes necessary to adjust for in your recipes, because at the end of the day it's what you taste, not the number of IBU's on your spreadsheet.
 

Liam_snorkel

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yes. one time I heavily dry hopped an underwhelming pale ale with Wai-iti (AA ~3-4%) and it made the beer taste much more bitter. Like bitter lemon peel.

MHB said:
Absolutely not, dry hoping can't add any bitterness because Alpha Acids are practically insoluble in "cold" (say under 60oC) water/wort/beer and don't become soluble until isomerised by boiling (or at least being hot for a long time).

I suspect that a lot of home brewers cant tell the difference between Bitterness and Hop Taste. Quite a lot of hop taste can be extracted when dry hopping, it just isn't really bitterness.
If you put some hops in a bit of water and boil them for an hour, add the same amount of hops to tap water and leave them to soak overnight at air temperature, taste the two side by side at the same temperature, one will be bitter the other has hop taste
Might help you to differentiate between the two.
Mark
MHB said:
Someone should look up the definition of IBU's, it has little to do with "taste" but is rather a measured quantity, like Colour or SG.

An International Bitterness Unit (IBU) is a measure of the bitterness in beer. One IBU is equal to one milligram of isomerized alpha acid per liter of beer. Isomerized alpha acids are the main bittering acids derived from hops.

Even a quick read of Wikipedia will help with an understanding of the subject.
Mark
the question was about bitterness (or perceived bitterness as Droopy said)

IBU is not the definition of bitterness, it is just a convenient way of measuring the contribution of bitterness by the isomerisation of alpha acids.

so heavily roasted malt isn't bitter because it doesn't contain isomerised AA? My fat aunt Fanny
 
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