Full vs. Partial Boil Question

I'm going to brew the Northern Brewer Dead Ringer IPA recipe tomorrow and I'm debating doing a full boil. My kettle is plenty big, but I'm unsure about the hop utilization. I'm adding 1 oz at 60 mins, 1 oz at 20 mins, and 2 oz at 5 mins. They are all Centennial and I have 2 oz for dry hopping. This is what the recipe calls for, but the recipe also states these at a a 2.5 gallon boil. What are your thoughts of doing a full boil? What will be the effect of doing the full boil?

 

What I did for a full boil was look at the directions for the AG kit and use its hop schedule and amounts.

 

A full boil will yield better hop extraction because the wort is thinner. When you boil a lesser volume, the wort is thicker and yields less hop utilization. Whenever you can, do a full wort boil.

 

In my beer recipe book they always say to eliminate roughly 20 to 25% of the hop bill if performing a full boil. You will get better utilization of your hops.

 

I asked a similar question earlier this week, and I will be making it sometime next week. I converted it through Beersmith v2 and here are the approximate values for a full boil.

0.46 oz at 60 min
0.46 oz at 20 min
0.91 oz at 5 min

However, I wanted to increase the IBU, so I plan on doing this:
0.50 oz at 60 min
1.00 oz at 20 min
1.00 oz at 5 min

This will change the IBU from the original 2.5 boil extract recipe from 30.8 to 44 using my modified full boil version. If you want to increase the IBU even further, hold off on 6 lbs of extract until the last 15 minutes left of the boil (according to Beersmith's calculations). I know this defeats the purpose of a clone, but that's fine with me. If I like the outcome, I'm actually going to try a full grain using BIAB.

Based of what I've read, a full boil can improve the outcome of the homebrew. I can't wait to try it out. Let us know how it turns out.

 

The more wort being boiled the higher IBU's you will get out of your hops. Topping off with water at the end will dilute the wort.

 

You need to be careful though of adjusting late additions. Hop utilization is only for IBUs and does not affect flavor and aroma compounds the same. I'm sure there is some difference in aroma and flavor "utilization" between full and partial boils, but I'm not sure that it is the same as for bittering. Increasing or decreasing late additions based on IBU adjustments will also impact flavor and aroma. I tend to leave late additions alone and only adjust the bittering additions. .

 

What about adding the extract late? I think I heard that adding the extract at the beginning of the boil will make the beer darker due to the caramelization of the sugars. My recipe calls for only LME. Should I add all of the extract the last 10 mins of the boil to avoid this? Should I add a little in the beginning to help with hop utilization?

 

I think you have it backwards, Dawg. LME won't help with utilization, it will inhibit it. The higher grav the wort, the less utilization. I always add LME late to keep it from caramelizing, and to aide in hop utilization. I also boil as much wort as I can.