Hop Utilization

[rodwha]

Is a full boil necessary to achieve pulling the AA's out of hops?
I want to take full advantage of my IBU's (I love IPA's) without losing much in boil off.

 

[helibrewer]

Some fairly recent articles seem to indicate that there isn't much of an effect on utilization between full and partial boils.

 

[rodwha]

What I'm trying to ask is does my water need to be 212* +? Or will say 200* bring me the same IBU level I would have achieved?
I'm boiling 4 gals of water in my 5 gal pot now to see how much boil off I get.

 

[remman4]

I don't have any data to back this up, but my hypothesis is that's full boil will result in faster/ better isomerization but you could do a longer sub-boil temperature "boil"

 

[40watt]

I learned something VERY IMPORTANT about this topic. At the time I didn't know why, and I'm sure there will be a bunch of people who didn't have this problem.

On my first batch I did a full boil extract batch with all extract added near the end. I didn't adjust my 60 min hop addition, because I was skeptical that it could be more bitter than I could handle.

What I didn't know was the role of ph in the boil regarding hop extraction. My water is such that it needs the sugar from the wort for a proper ph range.

In the improper ph range, too high unless I'm turned around, that hop bitterness manifests in an acidic way that can only be described as BILE.

Steeping grains seem to provide enough of a buffer to avoid that character. If you have no grain, and don't know your water profile, I would proceed with caution.

 

[ChadChaney]

You should also look into first wort hopping.

 

[rodwha]

I've reduced my yield volume to 4 gals now since my pot is only a 5 gal, and I'm trying to take full advantage of my hops. I like to put a gallon of top off water in the freezer to help bring the temp down, but I don't want to "water" it down much more than that.

 

[jimbot]

I had read a couple months ago that some brewers experimented with reducing the temp of the wort while whirlpooling, compared to keeping it at boil. They found that when the temp was reduced much (like 10-20 degrees only below 212C) then the hop oils wouldn't/couldn't go into solution as easily. This tends to make me think that boiling water temp is essential for isomerization.

I also think I remember that John Palmer indicated that wort gravity doesn't have as much affect on utilization than was once thought. It does have some affect, but it might not be detectable. Boiling hops in as much water as possible will yield better utilization, but you get to decide if its worth handling the extra water in your kettle.

Check these charts:
http://www.realbeer.com/hops/research.html

--Jimbot

 

[rodwha]

"They found that when the temp was reduced much (like 10-20 degrees only below 212C) then the hop oils wouldn't/couldn't go into solution as easily. This tends to make me think that boiling water temp is essential for isomerization."

That's what I figured.