Late hopping recipe advise! Things of note?!

[Simonok]

I've recently been tasked by my boss to brew a very hoppy BIPA, this will be my first recipe formulation for this brewhouse 12bbl, the headbrewer hates hoppy beer, so I'm really in the spotlight here and there'll never be more than 5lbs used on a single batch again ;-)

I have a recipe trialled on homebrew system, it's with a traditional bittering addition to 54ibus and all other additions at 5m and KO.

Ive redone the recipe to get most of my IBUs from late hop additions.
My current hop charge stands as

OG 1.065

Current calculated IBUs 53
3 IBUs @75m
33 IBUs @15m
12 IBUs @ 10m
5 IBUs @5m

Then 2kg of 14%aa and 4kg of 5.5% at knock out.

I've had successes with all late hopping on my homebrew system.
But Im wondering if there is anything of note that I should be aware of using this technique on a pro brew house and am I leaving enough headroom in the IBU department for uncalculated utilisation during the steep? Aiming for 60ibu.

[anthonybaraff]

It's really difficult to tell if you are correctly calculating your IBUs. What weight of what alpha hops will you be adding to the boil/whirlpool? I think you will find that commonly used brewing algorithms while adequate for home brewing massively underestimate IBU contributions of late hop additions. What is the knock-out process on your system? Flame out, whirlpool for 5 minutes, let settle for 20 minutes, chill for 40 minutes? If so the, 5 minute addition of hops is actually contacting near boiling wort for 30-70 minutes. Matt Brynildson of Firestone Walker says he gets 15% utilization in from whirlpool additions vs 35% for kettle additions Take a look at the "Hop-Utilization-of-Whirlpool-Additions" post on this site. One brewer estimates 13% from whirlpool, another cites 10% to 20% utilization, this one cites 10-18%... I was told by the brewers at Thornbridge that they get around 20% utilization from their whirlpool hops. I think you get the idea.

Try playing around with the Hop utilization tool on the site located here: http://www.probrewer.com/resources/tools/bitterness.php

My guess is that a flame out addition on your system will probably at least be the equivalent of a 20 minute addition.

Hope this helps,

Anthony

[Simonok]

Knock out process is normally 5 minutes whirlpool and 20minutes settling time, with about an hour to cast into the fermenter...so yeah I get the idea alright. So am I looking at higher utilisation all my additions?

[anthonybaraff]

That's what I'd do. If your whirlpool utilization is 11% which corresponds theoretically to a "15 minute" addition. I'd calculate your 5 minute addition as a "20 minute" addition. When you start to try to get higher levels of bittering (40+) IBU you'll probably find that you start to undershoot your intended IBUs in the finished beer. Mikkeller's 1000 IBU only registered at 140 IBU when independently tested despite having 7.2 kg of 53%AA hop Extract added to a 8.5 BBL batch at the start of the boil.