Full boil hops confusion

<--Noob. Winemaker for years, moving on to something better. More room to experiment, can drink it sooner.

I have a BB kit in the primary now. Used partial boil for that.

I bought an Irish Stout BB kit, but also hooked up with a new Turkey Fryer that will be christened today for the next batch on a full boil instead.

I've seen conflicting advice on the hop additions when taking a kit from partial to full boil. Some say to cut back on the bittering hops, since it's a lower gravity boil. Others say it doesn't matter.

Bittering hops are Pallisades 1.25oz 6.7%, add at beginning of boil.

Aroma are German Spalt select, 1.5oz, 2.0% at 5 minutes remaining.

I'm leaning towards following the hop schedule as originally written.

Suggestions?

I believe hops utilization is based solely on the length of time in boil, and has nothing to do w/ the gravity of the wort, but I may be mistaken. I'd leave the hops as the recipe calls for as well. If it ends up a bit more bitter... its still going to be fine... you can just get your hop head friends to enjoy it more

pompeiisneaks said:

I believe hops utilization is based solely on the length of time in boil, and has nothing to do w/ the gravity of the wort, but I may be mistaken. I'd leave the hops as the recipe calls for as well. If it ends up a bit more bitter... its still going to be fine... you can just get your hop head friends to enjoy it more

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Solubility of the hop acids in wort is going to be affected by the wort gravity. So yes you should decrease them. By how much is the trick. Personally I think the effect is fairly negligible and I like hoppy beers anyways, so I wouldn't change a thing.

nathani said:

Solubility of the hop acids in wort is going to be affected by the wort gravity.

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Not really--see, e.g., https://www.homebrewtalk.com/f39/hop-utilization-confusion-180083/#post2085540

Personally I would stick with the recipe and see if this amount of bittering flavor/aroma is what you like until you figure out what you want out of your beer you can than answer this question for yourself if you feel the hop schedule/quantity needs to be adjusted it is all a matter of your individual likes and dislikes have fun and experiment

SumnerH said:

Not really--see, e.g., https://www.homebrewtalk.com/f39/hop-utilization-confusion-180083/#post2085540

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I'm not going to argue with experts. But intuition definitely tells me that the SG of the wort will affect the solubility of acids. Imagine if you have a 100% maltose compound. You would get 0% extraction from the hops. Like I said, the effect is negligible (especially since wort is 90% water), but I would think there is still a small effect.

This also depends on your recipe - if your recipe was built for partial boils, it will include more hops, as your top-off water "dilutes" the boiled result. BeerSmith (free trial) is a good software package that allows you to enter your recipe (or make one up) and accommodates partial boils or full boils in the calculations. (lots of other tools, too. - many users on this forum)

Hang Glider said:

This also depends on your recipe - if your recipe was built for partial boils, it will include more hops, as your top-off water "dilutes" the boiled result. BeerSmith (free trial) is a good software package that allows you to enter your recipe (or make one up) and accommodates partial boils or full boils in the calculations. (lots of other tools, too. - many users on this forum)

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I think it will only include more hops per gallon, or in other words IBUs. I don't have the software handy, will it actually add more total hops based on partial boils?

Correct - it won't actually "tell you" what to add - it will only give you the result of your recipe, based on factors such as full boil, amount of time boiled - in IBUs
If you enter a recipe as partial boil, and note the IBUs, gavity, etc. then change it over to full boil, you will adjust your recipe as needed to match your notes on the previous settings.

There are online hops calculators; you don't need something as complicated as Beersmith (save your free trial for when you want to make recipes). I doubt that a Stout recipe is going to be too bitter and most kits aren't high gravity. Go to the Green Bay Rackers or Brewer's Friend websites, use their hop calculators and see what IBUs you are going to get. Then compare that to the IBU range for that style.

Or, just put your bittering hops in at 55 min and call it a day

http://www.brewersfriend.com/ibu-calculator/

This is what I use, and you'll see the effects of different sized boils.

pkeeler said:

There are online hops calculators; you don't need something as complicated as Beersmith

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The problem is that most of the software uses algorithms that predate recent* discoveries--their assumptions for scaling to partial boils are way off. IMO, if you're doing all-extract you're better off lying to the software and telling it you're doing a full boil (and doing late addition of extract, which is still valuable for non-bitterness related reasons).

That's imperfect, as isomerized alpha acids will adsorb to break material and precipitate out, but it's a lot closer in my experience (and in the measurements BBR did of IBUs in full an partial boils) than the wild adjustments that software tries to make. With all-grain, there's more break material and the issue gets muddier.

*Recent in the homebrew world, though long-known to commercial brewers.

I appreciate the input. What I am hearing is this:

1. Stop over-engineering this. Hops is not exact science- it's a matter of taste.
2. Brew it up, either with partial or all of the hops.
3. Change the hops level next time if it didn't work out right.
4. Consider AG and getting Beersmith to experiment with (I have a cooler- just need to plumb it)
5. In the end- it's still beer!

+1 on #1 and #5. Like the old carpenter says, "Design to the millimeter. Mark it with chalk. Cut with an axe."