Boil Size

Hi all,

In a passing conversation with the LHBS guru, he mentioned that the size of the boil makes a difference in the amount of hops you use. I wanted to understand the difference in a 3 gallon boil and a 5 gallon boil. Is there a saturation point or somehting that makes the difference? I base most of my recipes off 3 gallon boils but end up doing 5-6 gallon boils.

Thanks!

Bigger boils = better utilization. You get more out of the hops, the more wort you boil...

http://www.howtobrew.com/section1/chapter5-5.html

You really ought to be adjusting your hops if you're taking 3-gal-boil recipes and doing a full boil. It's very easy to see the change if you stick the recipe in brewing software (such as beersmith) and change the boil size. Based on a quick check, it appears that taking a 3-gallon recipe and doing a full boil will increase bitterness (IBU's) by about 50%, which is very significant.

Soulive21 said:

Bigger boils = better utilization. You get more out of the hops, the more wort you boil...

http://www.howtobrew.com/section1/chapter5-5.html

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Sorry, but that's not true...

Right there in your reference it states: "hop utilization decreases with increasing wort gravity. The higher concentration of sugars makes it more difficult for the isomerized alpha acids to dissolve."

The important factor for bitterness extraction is the gravity.

In Charlie P's TCJOHB it states the MAXIMUM hop bitterness extraction of 30% is achieved at a gravity of 1.040.

1 lb of DME in 1 gal of water with 1 oz of hops is approximately 1.040.
Supersizing that to 5 gal and 5 lbs of DME would be the same (approximate)gravity. Adding more malt lowers the utilization.

I think by bigger boils he means "More Gallons In The Kettle" not "More Gravity In The Wort". Read the reference again. He's right.

homebrewer_99, I'm not quite sure I understand your point. At first glance it seems you are arguing the same point he was.

On closer inspection of Soulive's post, I guess there is one ambiguity - bigger boils at the same gravity do not mean increased utilization, but a bigger boil of a given recipe (with a certain amount of fermentables) would indeed increase utilization as compared to a more concentrated boil of the same recipe. Reading his response, it seems to me the "of a given recipe" was assumed, given the context of the original question, which was specifically asking about different boil sizes of a given recipe.

homebrewer is just clarifying that even a full boil might have lower hop utilization if its a really big beer...like a barley wine or something.

basically its the gravity within the volume, not the volume alone.

OK, I think you guys misunderstand my point...

His comment was: "Bigger boils = better utilization. You get more out of the hops, the more wort you boil..."

If a recipe calls for 8 lbs of DME (in 5 gals of water) the hop utilization will drop because it is a high gravity brew. Conversely, if only 4 lbs of DME is boiled in 5 gal of water with the same amount of hops the brew would seem overhopped (when infact it is really under-malted as in a good balance).

My point here is the extraction of the bitterness is maximized (at 30%) when 1 lb of malt is boiled in 1 gal of water with 1 oz of hops for a period of 60 mins (per Papazian's TCJOHB, 3rd Ed, Hop Utilization Chart, page 258), and utilization (bitterness extraction) is reduced the higher the gravity of the wort.

I am sure I'm misunderstanding "something", but this is how it is stated in the book.

As I see it the simple math would be to divide the smaller number by the larger to get the numbers you need to downsize the water/malt/hop requirements/measurements to keep the brew balanced.

I think people are saying the same thing in different ways.

GaryA said:

I think people are saying the same thing in different ways.

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Hey, anything's possible...

What you've said is correct, and what Soulive said is technically not correct, though I think he knew what he was talking about but just said it wrong. Taken in the very specific context of this thread, what he said at least sort of makes sense.

In any case, to use your own example to illustrate what I was saying - yes, if you put 8 pounds of DME in 5 gallons of water, hop utilization will be lower than if it were 5lb/5gal. But if you took the same 8lb DME and did only a 3gal boil, it'd be even lower. In the context of the original poster's question, if a recipe calls for a 3gal boil and you switch it to a 5-6 gal boil with all the same ingredients, no matter how high the gravity is (well, maybe not if it was INCREDIBLY low to begin with), the hop utilization will be higher than the recipe intended, usually significantly.

It's definitely an important thing to note - a lot of ingredient kits assume a really small boil, like 1.5 or 2 gallons. Beginners go on forums like this one, and everyone tells them it's best to do as large a boil as they can, so they go out and buy a huge stock pot and go to a 3-4 gallon boil or larger, without realizing they need to change the hop schedule - and then they end up with their beer being literally TWICE as bitter as it was supposed to be. Might lead them to wonder why people say large boils are so great. This is exactly what I did when I got started, and my first 2 or 3 batches were WAY too bitter as a result. The first one especially - if I wasn't so excited about it since it was my first batch, I probably would have given it all away to people I didn't like or something

Funkenjaeger said:

What you've said is correct, and what Soulive said is technically not correct, though I think he knew what he was talking about but just said it wrong. Taken in the very specific context of this thread, what he said at least sort of makes sense.

In any case, to use your own example to illustrate what I was saying - yes, if you put 8 pounds of DME in 5 gallons of water, hop utilization will be lower than if it were 5lb/5gal. But if you took the same 8lb DME and did only a 3gal boil, it'd be even lower. In the context of the original poster's question, if a recipe calls for a 3gal boil and you switch it to a 5-6 gal boil with all the same ingredients, no matter how high the gravity is (well, maybe not if it was INCREDIBLY low to begin with), the hop utilization will be higher than the recipe intended, usually significantly.

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Thanks, I tend to not clarify myself when posting. I guess I've been too lazy with my replies

Soulive21 said:

Thanks, I tend to not clarify myself when posting. I guess I've been too lazy with my replies

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I, too, try my best to be clear, but am not always successful...

Funkenjaeger: Right!! That's why I added that the recipe should be converted (5 gal to 3 gal) so one does not overhop.

I know I could have said it better, but what I said at the time was all I (thought) needed to be said.

OK...group hug!!!

homebrewer_99 said:

I, too, try my best to be clear, but am not always successful...

Funkenjaeger: Right!! That's why I added that the recipe should be converted (5 gal to 3 gal) so one does not overhop.

I know I could have said it better, but what I said at the time was all I (thought) needed to be said.

OK...group hug!!!

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Too many times I assume people will just know what I mean. I end up sounding like a noob brewer. Oh well

Soulive21 said:

Too many times I assume people will just know what I mean. I end up sounding like a noob brewer. Oh well

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No, that wasn't the case this time...

I think a lot of times all those experts (those who write the books) do as we do. We all have learned techniques and come up with our own...shortcuts and processes...not in the mainstream. Nothing wrong with that.

I've been doing 1.5 gl boils with 1 lb of DME using very little hops and have no plans to stop it in the future.