If doing partial boil from recipe kit it states to start with 2.5 gallons for starting ...would it be better if the pot I have would hold 3.5 or 4 gallons for initial boil then add the remainder to bring up to 5 gallons or is the 2.5 specific for initial boil
water volume question
- Thread starter luvinit
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I'm not really sure exactly what the effects would be, but I can tell you that your beer will, at least mathematically, be more bitter.
In partial boil kits, you have to boil more hops to get the same bitterness as you would doing a full boil because your hop utilization is lower in lower volumes of water.
So if you're adding the same amount of hops to your 4 gallons as you would to 2.5, it stands that your beer would have a higher bitterness.
Whether the change would be very perceptible, I don't really know.
In partial boil kits, you have to boil more hops to get the same bitterness as you would doing a full boil because your hop utilization is lower in lower volumes of water.
So if you're adding the same amount of hops to your 4 gallons as you would to 2.5, it stands that your beer would have a higher bitterness.
Whether the change would be very perceptible, I don't really know.
the more volume you can boil, the better. the extract will caramelize less in a larger boil and the hops utilization will increase in a larger boil are the two main reasons i can think of for doing a larger/full boil.
If you get any better hops utilization at all (not likely), it would be insignificant between a 2.5 gallon boil and a 4 gallon boil anyway- so that isn't anything to worry about. (There are some interesting new-ish things from John Palmer on hops utilization, basically stating he was wrong in his book about hops utilization decreasing due to wort gravity, and that indeed IBUs and hops isomerization are independent of wort gravity.)
I really think the more you can boil in the beginning, the better the result. One of the things I noticed in a bigger boil is a less 'cooked extract' taste from less maillard reactions from a concentrated boil. Another thing that helps is adding the bulk of the extract late in the boil- with 15 minutes or less. I personally like adding the majority of the liquid extract at flame out. The extract has already been processed once, and boiling it again for a long time gives it a carmelly/cooked taste that I don't find in all-grain beers.
In short (I know, already too late), boil as much as you can and add the bulk of extract near the end of the boil. That will more closely simulate the same batch as an all-grain batch.
I really think the more you can boil in the beginning, the better the result. One of the things I noticed in a bigger boil is a less 'cooked extract' taste from less maillard reactions from a concentrated boil. Another thing that helps is adding the bulk of the extract late in the boil- with 15 minutes or less. I personally like adding the majority of the liquid extract at flame out. The extract has already been processed once, and boiling it again for a long time gives it a carmelly/cooked taste that I don't find in all-grain beers.
In short (I know, already too late), boil as much as you can and add the bulk of extract near the end of the boil. That will more closely simulate the same batch as an all-grain batch.
Great point, Yooper. I've been hearing that a lot lately and it's very interesting. And I makes sense, as does the better hops utilization in a thinner liquid. I personally haven't noticed a real change in the hop profile in a full boil compared to that in a partial boil myself, so it made alot of sense when I first heard that gravity might not affect utilization after all. I've just acquired some 1 gal jugs to do experimental batches on, I think one of my experiments will have to be hops utilization in full vs. partial boils on the same recipe.
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I think when I first heard it, it was verbally from Palmer. I thought it was recorded at an NHC, but possibly not. We discussed it a couple of times at NHC 2008, and briefly the next time I chatted with him, probably in 2010. But we talked about some other things, too (like trying to clone Capitol Brewery's Blonde Dopplebock) and we had been drinking by that point so I can't remember the details all that well. There must be some notes or recordings somewhere from his actual presentations and writings, but I don't know where to find that.
But I do know that there is a Basic Brewing Radio podcast, probably from 2009 or thereabouts that is called "What is an IBU, really?" that has some basic information on IBUs and what impacts hops utilization.
Hops utilization is one of those "unexact" science things. There are different scales, and none of them accurately account for things like FWH, whirlpool hops, and so on.
The thing to do is find a scale that works for you and stick with it. Because it really doesn't matter if your beer is actually 40 IBUs or 50 IBUs if lab tested. What matters is the balance of the beer, and your consistent results. I mean, if a beer tastes underbittered, the actual IBU level doesn't matter, if that makes sense.
If you're a member of the AHA, there's a pretty scientific audio presentation from the 2011 NHC by Charlie Bamforth in the members audio section.
You should be able to see the Powerpoint slides:
34th Annual National Homebrewers Conference Hopping into the Sunset
But from just browsing them, they don't explain as much as the audio.
You should be able to see the Powerpoint slides:
34th Annual National Homebrewers Conference Hopping into the Sunset
But from just browsing them, they don't explain as much as the audio.
Thanks Yooper. I've got all the old episodes of BBR on my iPod so I'll check out that one.
Since I'm new to homebrewing, I'm using BeerSmith to give me a hand in recipe design. Just for curiosity's sake, I checked their estimated IBUs on an IPA I'm working on with all the malt extract for 60 minutes, half for 60 and half 1, and all for 1 minute. The results are 45.6 IBUs, 72.2, and 105.7. Seems like a pretty huge swing for using the same amount of hops. Obviously, I'd never boil all the malt extract for just one minute, but I'd like to know exactly how they calculate for the boil gravity variable.
Since I'm new to homebrewing, I'm using BeerSmith to give me a hand in recipe design. Just for curiosity's sake, I checked their estimated IBUs on an IPA I'm working on with all the malt extract for 60 minutes, half for 60 and half 1, and all for 1 minute. The results are 45.6 IBUs, 72.2, and 105.7. Seems like a pretty huge swing for using the same amount of hops. Obviously, I'd never boil all the malt extract for just one minute, but I'd like to know exactly how they calculate for the boil gravity variable.
