Boil size vs. hop efficiency

[kevinb]

Sorry if this is a repeat, but I can't find my answer by searching.

I am brewing an extract kit. The instructions call for a boil size of only 1.5 gallons. I think I have heard that the larger the boil size, the better the beer will turn out. If I keep the recipe the same, but boil 3 gallons instead will the flavor of the beer change significantly (more bitter, stronger hop flavor?)

 

[Face Eater]

I know hop utilization will be different when boiling a larger amount but not sure how to correct it. Hopefully someone will chime in with the answer.

 

[SilverZero]

If you're just going to top it off for a full batch anyway, might as well boil it all up front. You will get increased hop utilization, which may be a good thing or a bad thing depending on how the recipe was designed. If it was written for 1.5 gallons and you boil 3 gallons, and get some extra IBUs, you may end up with more bitterness than you want.

 

[Yooper]

The hops utilization between a 1.5 gallon boil and 3 gallon boil is insignificant. boil as much as you can, and the beer will be better for it.

 

[kevinb]

Yooper, will do, sounds like good advice. Can you explain to a noobie how the beer improves with a large boil size? Is bigger always better? I think my brew pot is large enough that I can boil 4 gallons, should I go for it?

 

[JohnnyNeurotic]

The gravity of your boil GREATLY effects your hop utilization.

So we'll assume you're adding, let's say, 6lbs of DME and doing a 1.5 gallon boil - the gravity of your wort is VERY high. By doing a slightly larger boil you're increasing hop utilization because your gravity is lower.

Doing the most simple math possible, here's an example..

A 1.5 gallon boil including 6 lbs Light DME, 1 oz Willamette (4.5% AA) @ 60 mins and you'd end up with about 5 IBUs total

The same amount of DME and hops in a 3 gallon boil would bring it to 10 IBUs because your starting gravity is much lower, thereby increasing your hop utilization.

And no, lowering the gravity of your boil won't change your final, target gravity.

 

[KISS Brew]

I think my brew pot is large enough that I can boil 4 gallons, should I go for it?

I would go for it, but your beer will be fine either way.

 

[ludomonster]

The gravity of your boil GREATLY effects your hop utilization.

This is not true. While the boil gravity affects hop utilization, it doesn't have a dramatic impact. Here's a discussion on the topic at Stack Exchange.

 

[billl]

This is a matter of some debate. There are a couple different estimates for hop utilization but honestly, almost nobody pays for a true IBU test to see if their brewing method is hitting the projected marks.

Just based on personal experience, the bitterness taste of my brews got a lot closer to their commercial counterparts for full volume boils. Using the formulas/calculators that account for gravity differences got partial boils closer, but the bittering didn't seem as smooth. The partial boils weren't "bad" (at least once I figured out what I was doing. ) they just had a little sharper edge.

 

[crazyworld]

Isn't there something to be said about steeping grains too here? Conceptually it's right on par with the hops utilization. The more water the grains have to steep in, the less saturated with sugars it will already be and the more willing it will give up its sugars to the liquid. Again, you're probably not talking huge differences here as your steeping grains are typically only a pound or two. However, pair that with the increased hops utilization and IMO you'll strike a pretty close balance between the two and you can forget about either effecting the final outcome in a negative fashion.

 

[JohnnyNeurotic]

I'll just agree to disagree and assume that all of the guys - who are a lot smarter and more experienced than me - who came up with hop utilization formulas were correct.

In my early experience with extract brewing, especially IPAs, the size of my boil had a huge impact on bitterness and the harshness of that bitterness.

IMHO, err on the high side of your boil size when you can.

 

[SilverZero]

So I think the only question here is whether hop utilization will increase too much with a full(er) boil. I say it will be fine, but there's a chance it may be noticeable in the bittering additions.

I think the only way to know is to do a batch with a small boil and then do the same one with a larger boil, then compare. Or, at least, do the big one and see if you like it. If it's good, all's well that ends well.

 

[danorocks17]

making the switch to full boils gave me the greatest improvement in my brewing to date. Boil as much as you can and your beer will better.

 

[crazyworld]

I think the only way to know is to do a batch with a small boil and then do the same one with a larger boil, then compare. Or, at least, do the big one and see if you like it. If it's good, all's well that ends well,

That's it, brew one for the team! I love the idea of side by side brewing; you can learn so much from one experiment and that knowledge will travel with you the rest of your brewing career. Not to mention, you can share your knowledge and experience here for all to learn! Just make sure you use as little variables as possible to increase your chances of understanding more completely what is changing.

 

[kevinb]

Thanks for all of the feedback. I will go for it and try to use 3 gallons vs the recipes 1.5 gallon. Hopefully I get smoother but not more bitter.

 

[kevinb]

If it helps, this is my grain bill
5.5# light LME
1.1# Wheat LME
160z Chocolate malt
8 Oz victory malt
8 Oz flaked barley
1 Oz Nugget hops - 60 min
1/2 Oz willametter Hops - 10 Min
1/2 Oz willametter Hops - 1 Min
Yeast - Safale S-04

 

[Yooper]

Yooper, will do, sounds like good advice. Can you explain to a noobie how the beer improves with a large boil size? Is bigger always better? I think my brew pot is large enough that I can boil 4 gallons, should I go for it?

Yep, "bigger is better" in this as well as some other things. The reasons are diverse, but one of the reasons is that a larger boil will have less maillard reactions and hence less carmelization type of taste and less of a "cooked extract" taste.

The gravity of your boil GREATLY effects your hop utilization.

Actually, no it doesn't. The science since 2008 would dispute that as well. John Palmer said he "got it wrong" when he stated in his book that gravity has any effect at all on IBUs.

I'll just agree to disagree and assume that all of the guys - who are a lot smarter and more experienced than me - who came up with hop utilization formulas were correct.

In my early experience with extract brewing, especially IPAs, the size of my boil had a huge impact on bitterness and the harshness of that bitterness.

IMHO, err on the high side of your boil size when you can.

The reason really high IBU beers, like IPAs, have a lower IBU rating for a partial boil has nothing to do with wort gravity.

There are a max amount of hops oils that can isomerize in any gravity wort- generally thought to be 100 or so. That means that, regardless of theoretical calculations, there can never be more than 100 IBUs in any beer. Even the 100 figure is considered to be high, and many brewing gurus state it's more like 80-90. In any case, even assuming 100 is the max, there is a very good reason why an IPA with a partial boil isn't bitter enough.

Say you boil 2.5 gallons of wort and manage to get 100 IBUs in it. Then you add 2.5 gallons of top up water. That means you just diluted your IBUs to 50 for 5 gallons! That right there would explain a huge difference in calculated IBUs and has nothing to do with wort gravity. It's even worse when you consider that the actual maximum might be 80 IBUs. In a 2.5 gallon boil, topping up with 2.5 gallons of water means a max of 40 IBUs total in an IPA. That's one reason a bigger boil is better for bitter/more balanced beers.

 

[lebucheron]

Interesting stuff. I'll be sure to do a bigger boil for my next IPA attempt...

 

[NordeastBrewer77]

Thanks for all of the feedback. I will go for it and try to use 3 gallons vs the recipes 1.5 gallon. Hopefully I get smoother but not more bitter.

If it helps, this is my grain bill
5.5# light LME
1.1# Wheat LME
160z Chocolate malt
8 Oz victory malt
8 Oz flaked barley
1 Oz Nugget hops - 60 min
1/2 Oz willametter Hops - 10 Min
1/2 Oz willametter Hops - 1 Min
Yeast - Safale S-04

Your beer will thank you for it. Yooper summed it up really well in her post above, it's the wort that is affected by the smaller boil, larger boil = less darkening, caramelizing, etc. As far as hops go, the difference will be minimal, but the overall brew will benefit from the larger boil.

 

[EvilDeadAsh]

Isn't there something to be said about steeping grains too here?

I don't have the exact thread (threads?) bookmarked, however, I have seen Yooper suggest about 1.25G per pound of grains. If you use too much water, it throws off the pH and ultimately the flavor. I'm sure Yooper or someone more experienced can explain this more thoroughly, but that is my understanding.

Point being: If you do decide to do a larger boil, you will still want to steep the grains in a smaller volume of water, then combine everything when you add in the fermentables, hops, etc...

 

[NordeastBrewer77]

I don't have the exact thread (threads?) bookmarked, however, I have seen Yooper suggest about 1.25G per pound of grains. If you use too much water, it throws off the pH and ultimately the flavor. I'm sure Yooper or someone more experienced can explain this more thoroughly, but that is my understanding.

Typical water/grist ratio would be 1.25-1.5 qt/lb of grain. Too thick a mash can result in low efficiency, and too thin a mash can have too high a pH, which can cause issues with tannin extraction and efficiency. I shoot for 1.25 qt/lb most of the time, but have gone a lot thinner than 1.5qt/lb for bigger (higher OG) batches or batches with a large percentage of darker malts.

 

[ncbrewer]

John Palmer said he "got it wrong" when he stated in his book that gravity has any effect at all on IBUs.

The experts apparently are not in agreement on this point. Glenn Tinseth’s website still has the formulas that include a “bigness factor” (factor for wort boil gravity). Since there is some disagreement, I e-mailed Mr. Tinseth and asked about the gravity factor. His answer was “There is really no question about whether alpha acid utilization is related to wort gravity.” I personally feel that I can taste the additional bitterness when using late extract addition.

 

[EvilDeadAsh]

Typical water/grist ratio would be 1.25-1.5 qt/lb of grain. [...] I shoot for 1.25 qt/lb most of the time, but have gone a lot thinner than 1.5qt/lb for bigger (higher OG) batches or batches

Was that a typo? Quart, or gallon?

 

[david_42]

The gravity of your boil GREATLY effects your hop utilization.

No, this was dis-proven years ago. Hop utilization is only dependent on the amount of alpha acids in the solution. Doubling the boil volume cuts the alpha acid concentration in half and promotes higher utilization, but boil water, boil wort, only the AA concentration matters.

[Pardon the science to all of the opinionated folks out there]

 

[Yooper]

The experts apparently are not in agreement on this point. Glenn Tinseth’s website still has the formulas that include a “bigness factor” (factor for wort boil gravity). Since there is some disagreement, I e-mailed Mr. Tinseth and asked about the gravity factor. His answer was “There is really no question about whether alpha acid utilization is related to wort gravity.” I personally feel that I can taste the additional bitterness when using late extract addition.

Weird, because he told me that "it could be related to break material" instead of wort gravity. Palmer told me the same thing.

The interesting thing is, I still use Tinseth's IBU calculators because it is the best that is available. It works quite well in full boil AG batches, and I'm happy with it.

The thing that I've found is that in lower IBU beers, a difference of even a few IBUs is noticeable (say, in a 12 IBU beer for example). But in a beer with IBUs of 40+, it's almost impossible to tell even a 10 IBU difference.

 

[NordeastBrewer77]

Was that a typo? Quart, or gallon?

1.25-1.5 QT/LB of grain

 

[billl]

"[Pardon the science to all of the opinionated folks out there]"

That graph certainly doesn't show anything about utilization being independent of gravity. All that shows is a saturation effect. ie the more hops you add, the less of an impact the next addition will have.

 

[ludomonster]

The interesting thing is, I still use Tinseth's IBU calculators because it is the best that is available. It works quite well in full boil AG batches, and I'm happy with it.

I think in the same podcast, they talk about the validity of the Tinseth & Rager formula's. They said that both formulas don't calculate the bitterness of your beer correctly. However, they've been used for quite some time to reliably make good beer.

Because they are both estimates, they can't take into account how much of the alpha acids have isomerized. There are a lot of factors that can contribute to the actual values, including the amount of solids in the wort, the vegetative matter, the wort volume, the vigor of the boil, and so on.

The bitterness also depends on the malt character of the beer, as stouts and porters can high high IBU, but be very balanced.

What Jamil recommended was to pick a formula and stick with it. If you have a process that doesn't change much, two beers with similar IBU's and malt profiles should be similarly bitter. If you and a friend brew the same beer on different systems, don't expect them to be exactly the same.

 

[kevinb]

1.25-1.5 QT/LB of grain

I am a little confused (OK a lot confused). My recipe only has 2# of grains, the rest is all extract. Does that mean I should only steep the grains in 3 Qt of water?

Would I then add the extra water when I start the boil?

The instructions that I have say to steep in 1.5 gallons, add the LME and then bring to a boil.

 

[Yooper]

I am a little confused (OK a lot confused). My recipe only has 2# of grains, the rest is all extract. Does that mean I should only steep the grains in 3 Qt of water?

Would I then add the extra water when I start the boil?

The instructions that I have say to steep in 1.5 gallons, add the LME and then bring to a boil.

With only 2 # of steeping grains, you can steep in a larger volume if you really want to. But I always recommend using no more than 2 quarts per pound, since you can use that amount for EVERY batch. For AG batches, partial mashes, steeping grains, etc, you can use 1.25-2 quarts of water per pound of grain and be correct. It was just easier for me to always do the same procedure and not have to wonder if I had grains that should be mashed or only crystal malts that could be steeped.

After you're done steeping your grains, you can lift them up out of the liquid and pour 170 degree water over them, up to your boil volume.

If it makes your life easier to steep 2 pounds of grains in 1.5 gallons, instead of 1 gallon, that's fine, though.