Concentrated boils and hop utilization

General Homebrew Discussion
1

I was reading yesterday that supposedly John Palmer and others now state that hop utilization is independent of wort gravity.  These were third person attributions on another forum with no reference to source material, but others seemed to agree and take this as a known and generally recognized fact.

I had never heard this before.  Ever.  And I can’t find anything in (admittedly brief) searches on-line that would support the attribution of this statement to Palmer other than third party attributions.  As a matter of fact, almost all links take me back to that same forum…

Anybody heard this before?  I suppose it could be total BS but I simply don’t know.  It has always been my understanding that a concentrated wort had lower hop utilization.  Is the consensus changing?

I’m curious to know in general and especially since there have been a couple recent posts here about concentrated boils.

Maybe someone can chime in on the science behind all this.

2

I’ve heard that too, but never seen an attribution, let alone data. In Hops (p188) Heironymous does say that utilization is inversely correlated to wort gravity, and as a general rule I trust that he was as up-to-date as anyone in the industry, but it did go to press almost two years ago now.

3

There were some references to a paper that said it was not the sugars, but beak material that inhibited utilization. More gravity will have more break with it.

4

Can those sources be posted here? I’m curious.

5

How would you differentiate the impact of the sugars vs. the impact of the break?

If there’s more break with higher gravity than it still seems that hop utilization and wort concentration would be highly correlated.

6

If you are using Malt Extract, break material is extremely reduced, so that may be part of it.

7

Yeah, that would be the way to test. If the correlation is specific to the break material then an all-malt-extract brew should have a higher utilization than an all-grain batch of the same boil gravity. If it’s related to the sugars, then it should be the same for either. Also, if utilization really isn’t affected by sugar concentration then an all-extract brew should have the same utilization regardless of the boil gravity.

8

I have heard of those papers, but no links. Those were also discussed briefly on the Brew a Strong with Dr. Tinseth.

You might try and contact John Palmer.

9

Is break that reduced in an extract brew?  Are the maltsters removing that much break material?  I never noticed this.

10

It just seems like a big shift in thinking to have nothing people can point to as far as data.

I realize a lot of our truisms have been discarded over the years but I’d like to at least hear anecdotal evidence on this one.

11

Well, the White Labs IBU assay is only $38…

12

Coastal labs is only $5. Shipping is the expensive part.

This would be a good experiment to submit for an AHA research proposal. If I had time to do it in the near future I’d do it myself.

13

Ooh, good to know. Although the WL kits include shipping, so it might be a wash.

I may just write this up, actually. I forgot about the new AHA program.

14

If you do it, please post back.  Or write an article for Zymurgy.

15

Could explain the difference between FWH and a standard bittering addition.

16

I have been thinking about writing this up and sumitting, but as I am retired, it is hard to find the time, err motivation.

17

Would anyone like to collaborate? I think there are several variables that could be explored. Equipement would be different for different brewers. We could standardize to RO water and certain salts added. Hops would need to be common. Procedure would be agreed upon.

I could see doing Pils malt, Maris Otter, LME , DME to see if there are difference to break material quntity. I would split batches, boil one with hops, boil-chill-remove break, boil again and add hops for each.

What does any one think?

Edit - same yeast and pitch rates.

18

I like the idea.  Another way to get one with no break would be to use only sucrose to get the gravity up, though I suppose you’d need to make sure you match the pH with the malt batches.

For a collaborator you might want to approach Brad Sturgeon of Monmouth College.  He is a homebrewer and professor, and he and his students do IBU measurements in the lab.  I have listened to several podcasts where he was involved in some kind of IBU experiment or another so this would probably pique his interest.

19

Not that it adds anything new to this thread, but as I was reading the latest Zymurgy last night I noticed that the article on hop bursting by Mitch Steele makes reference to reduced utilization in higher gravity wort.

Which gives me some comfort that I’m not crazy.

I’d love to say I’m willing to collaborate, Jeff, but with three kids I hardly have time to brew as it is.  Good luck.

20

You gotta think pils malt gives the most break.

I’d mash and take the wort, split it and then boil one half just long enough to get break then let it settle.  Take the calrified wort off and then match the two wort volumes and do a side by side brew.  Analyze the two of these for IBUs.  This ought to give you some idea of the effect of break material.

Of course, other than general scientific knowledge, what practical significance does this have?  I don’t see anyone pre-clarifying wort like this as a general practice.  It costs more in time and energy than you could evere hope to save in hops.