Fewer hops for a full boil?

[belsonc]

Ok, I think my mind's just not functioning here, but can someone explain something to me? I'm making my Saison tonight with a kit from Northern Brewer - and it says that if you're doing a full boil, to cut your bittering addition in half. Why would that be? Wouldn't you need more bittering hops for a greater amount of wort? Thanks in advance...

-CB

[beerking]

You do not need hops by the amount of wort you boil, you need them based on the amount you end up with, and more importantly, the amount of malt in the wort.
If you boil 2.5 gallons down to 2 gal, then add 3 gal cold water, you end up with 5 gal wort ready to ferment.
Likewise, if you start the boil with 6 gal, and boil down to 5 gal, you have 5 gal of wort ready to boil. Same amount.
More importantly, you add the IBUs to balance the gravity points, or amount of sugars in the wort, NOT the amount of wort.
The reason for adding less hops to a full wort boil is your alpha acid utilization is greater. Higher gravity wort does not isomerize as much alpha acid as lower gravity in the boil.
All that being said, I would not cut back the hops by 50%. 15%, maybe as much as 25%, but not 50%.
Then again, a Saison does not have much hop character. You would not want to over do the hops in this style.
Take a gander at some recipes online, and compare how much IBU they are using to what you have. (Or, even easier, compare the AAUs, alpha acids times ounces of hops).

[gestyr]

Well the less dense the wort, the more efficiently it causes the reaction needed to utilize the bittering acids in the hops. If you are not doing a full boil then the wort is much denser until you bring it up to volume after the boil.

[belsonc]

Well the less dense the wort, the more efficiently it causes the reaction needed to utilize the bittering acids in the hops. If you are not doing a full boil then the wort is much denser until you bring it up to volume after the boil.


Ok, I think I got it now. Beerking, I got the general idea from your post, but I think gestyr drove it home. So now I understand moreso why it should be done - once again, realbeer.com succeeds! :-)

[gestyr]

We are here to help. We all had questions starting out. Maybe I shouldn't tell you this, but the questions increase as you go on. The more you know, the more you realize that you need to know more. :)

[belsonc]

You know, gestyr, there's a little piece of my brain that tells me I shouldn't ask so many stupid questions on this board.


Then the rest of my brain kicks that small part of my brain's figurative rear end for just the reason you just mentioned. a, they're not stupid questions (the only stupid one is the one not asked), and b, you guys all had to learn this stuff somehow, somewhere, sometime. Now you get to pass on your knowledge and teach others.



Man, I feel like I'm giving a graduation speech or something... ;-)

[paulcgi]

oh man.. beat me to it. I saw your post but was on my wife's computer and couldn't remember my RB password.. oh well.
the only thing I'll post is that if you go and look at the formulas that are used to calculate IBU for a given hop addition. there are 2 major factors involved in figuring for a given hop alpha %. those are 1) gravity and 2) time
the first (gravity) is inverse, IE: the higher the gravity the lower the utilization while time is one to one (not the term I want, but can't think of it now.. opposite of inverse) up to a certain point. I think that most of what I read is that you can't ever get more than like 35% utilization (or some number close to that)
because of point numbah wun above, a partial boil has a really high gravity (compared to full wort boil) therefore your utilization is much lower (50% lower based on the recipe from NB)

[belsonc]

So the boil is going on as we speak - and I screwed it up a little. as in instead of cutting it by 50 as NB suggested, or 20 as beerking suggested, I only cut it by about 10.

Oh well.



Looks like I'll have a hoppy saison.


But if you think about it, any time of year you brew is a hoppy saison...


/me hides from the impending assault of rotten produce ;-)

[beerking]

I have had some commercial Saison-style beers (brewed in the good ol' USA), that had more hops than is normally accepted for style. They were quite good.

[Dangerous Beans]

Well the less dense the wort, the more efficiently it causes the reaction needed to utilize the bittering acids in the hops. If you are not doing a full boil then the wort is much denser until you bring it up to volume after the boil.
I'm not sure this is right. I think the lower utilisation is due to the water being less able to dissolve things when it has large amounts of stuff dissolved in it.
When something is dissolved in water a network of water molecules forms around it, and as more stuff (sugar, isomerised hop oils) is added these networks start to interfere with each other. So as the wort becomes denser the isomerised bittering acids become less able to dissolve, and are more likely to be boiled off.
The chemical reaction that converts the bittering acids happens due to heat, you have to boil hops rather than soak them, so boiling wort of any gravity should do it.
That's my guess anyway.
Mmm, tasty chemistry :p

[gestyr]

We are sort of both correct. The isomerizing has to take place first to make the oils soluble in water. The density of the wort determines the amount of oils that are dissolved but the boil causes the oils to become isomers.

And yes, chemistry is fun. :)

[Mad Scientist]

I'm not sure this is right. I think the lower utilisation is due to the water being less able to dissolve things when it has large amounts of stuff dissolved in it.
When something is dissolved in water a network of water molecules forms around it, and as more stuff (sugar, isomerised hop oils) is added these networks start to interfere with each other. So as the wort becomes denser the isomerised bittering acids become less able to dissolve, and are more likely to be boiled off.
The chemical reaction that converts the bittering acids happens due to heat, you have to boil hops rather than soak them, so boiling wort of any gravity should do it.
That's my guess anyway.
Mmm, tasty chemistry :p

You got it right, don't worry. :)

[belsonc]

So in other words, then, denser wort = less "room" for the alpha acids = more of the AA being boiled off = more hops needed to actually get all the AA/IBU into the wort?

[gestyr]

So in other words, then, denser wort = less "room" for the alpha acids = more of the AA being boiled off = more hops needed to actually get all the AA/IBU into the wort?


Bingo! You get a cookie. :)

[beerking]

Bingo! You get a cookie. :)

I think he'd rather have a beer! :D
(or at least a pretzel)

[gestyr]

I think he'd rather have a beer! :D
(or at least a pretzel)


Hmmmm....IPA cookies....or maybe oatmeal cookies made with 80/.....that gives me an idea....or chocolate chip made with porter....

[belsonc]

Well, there's that recipe floating around on here for spent grain bread... why not cookies? :-) And I really need to get around to making pretzel dough - looks like it can't be that difficult...


(Also, for any soups I make in my slow cooker, instead of using something like beef broth, I just use a bottle of beer. Less salt. Yeah, that's it, less salt.) ;-)

[gestyr]

I have made beef stew in a crockpot with IPA instead of water. It is awesome