Reduced Boil Time for Late Extract Addition

[amcclelland]

I'm going to try a late extract addition in my next brew (NB Chinook IPA). Since hop utilization is dependent on wort gravity and duration of boil, it seems that I could reduce the amount of hops and reduce the boil time to obtain the same IBUs in the end. Would it be OK to do a 30 minute boil, or should I only reduce the hops and keep the 60 minute boil?

Original Recipe:
1 lb DME
6 lbs LME
1 oz Chinook (13% AA) for 60 min
0.5 oz Chinook for 10 min
0.5 oz Chinook for 1 min

IBUs by following the recipe are about 33, according to my calculations - based on Palmer's book.

Modified Recipe:
1 lb DME
1 lb LME
0.75 oz Chinook for 30 min
0.40 oz Chinook for 5 min
0.40 oz Chinook for 30 seconds
5 lbs LME at flameout

IBUs are 37 by my calculations.

Thanks!

 

[schokie]

I really doubt you'll notice a difference of 4 IBUs. That's almost nothing. I wouldn't worry about it.

There's debate over wort gravity affecting hop utilization. From my research it seems to be more a function of Ph and hot break material. Those tend to go hand in hand with higher gravity, but it doesn't mean the gravity itself is doing anything.

If you want maximum utilization, wait for the hot break to finish before adding your hops. That way you won't lose anything to boil overs or to foam sticking to the side of your kettle.

It certainly won't hurt anything to try your modified recipe, but my opinion is that it's too much hassle for such a minute change that you're not even going to notice.

 

[amcclelland]

Thanks for the advice. I did some more research based on your comments about hop utilization being more of a function of ph and hot break. Looks like I was working off of outdated info. I'll stick with the original recipe and just add most of the extract at the end of the boil.