IBUs when not doing a full batch boil

[dsabra11]

I just did an IIPA today but did not realize that doing a 3gal boil and then diluting it to a total 5 gallons would drop my IBU level from 113 to about 56. Is there anything I can do, post-boil and post-pitch, to increase the bitterness of my beer? Will it still taste like an IIPA or will it be more like a barley wine? How will dry hopping affect the overall flavor. This was an all-Centennial hopped 120 minute boil extract IIPA with an OG of 1.081. Thanks!

 

[Germelli1]

I just did an IIPA today but did not realize that doing a 3gal boil and then diluting it to a total 5 gallons would drop my IBU level from 113 to about 56. Is there anything I can do, post-boil and post-pitch, to increase the bitterness of my beer? Will it still taste like an IIPA or will it be more like a barley wine? How will dry hopping affect the overall flavor. This was an all-Centennial hopped 120 minute boil extract IIPA with an OG of 1.081. Thanks!

Actually I did the exact same thing with my first batch ever. I was brewing a IPA in 2.5 gallon boil then added 2.5 post boil. It brought my IBU down to upper 20's. For me it turned out perfect because the final product was great (although still aging in the bottles since i overshot the FG and wound up about 9%). I know you can dry hop it but what I am not sure about is whether that will effect the IBU or just the aroma.

 

[SumnerH]

I just did an IIPA today but did not realize that doing a 3gal boil and then diluting it to a total 5 gallons would drop my IBU level from 113 to about 56. Is there anything I can do, post-boil and post-pitch, to increase the bitterness of my beer? Will it still taste like an IIPA or will it be more like a barley wine? How will dry hopping affect the overall flavor. This was an all-Centennial hopped 120 minute boil extract IIPA with an OG of 1.081. Thanks!

It won't really dilute the IBUs nearly that much (your beer software may say it does, but that doesn't make it so). Exactly how much it will is a matter of much debate.

I wouldn't worry about it too much now, though you can try dry hopping to get some more hop character into the beer if you want. Centennial is a great dry hop.

 

[dsabra11]

Thanks, that is reassuring. I think it will still be delicious (looks and smells that way) but I was hoping to get a real strong douple IPA flavor. I guess the waiting game begins.

 

[SumnerH]

Well, if you're really worried about it you could listen to this:
March 4, 2010 - BYO-BBR Experiment III http://www.basicbrewing.com/index.php?page=radio

They brewed the same recipe with a full boil, a partial boil (topped off later), and a partial boil with late extract addition and sent it off to a lab for testing; it turned out the IBUs in all 3 versions were essentially the same.

Unlike what brewing books thought up until 2008 or so, hop utilization is independent of wort gravity; brewing software's IBU calculations are based on the old, inaccurate assumptions. Now, there is some amount of the bittering compounds that will adsorb to proteins in the boil and precipitate out, so a denser boil could in theory have less ultimate bitterness. But the lab test from that BBR experiment shows very little impact in all-extract brews from that.

OTOH, some home brewers report more noticeable differences than others. It's a pretty open field at the moment, but I would personally say with a lot of confidence that the difference will be nowhere near as big as the numbers you quoted originally.

 

[Germelli1]

Thanks, that is reassuring. I think it will still be delicious (looks and smells that way) but I was hoping to get a real strong douple IPA flavor. I guess the waiting game begins.

Actually mine was a double IPA and I gave it to homebrewing coworker who called it the best homebrewed IPA he has tasted. Worst case scenario: You may lose what you are looking for in a Double IPA but you will be left with a fantastic IPA.

 

[dsabra11]

Thanks for your help. Also would've been good to know ahead of time that a higher gravity/more hopped 5-gal wort would blow the airlock off my 6 gal carboy! Never had that problem before. Needless to say, I woke up to a terrible mess and was 2 hours late to work after scrubbing the ceilings, walls, floors, etc. and anything within 20 feet of my carboy. Switched it to a blow off but I don't know how long it was exposed (at most 6 hours overnight). Hopefully it did not get contaminated. We'll see. But, I will need a good name for this crazy beer. Calamity IIPA/IPA? Morning Sunshine IPA?