Do full boils make that much of a difference over partial boils?

[LVBen]

Well, no. IBU are "International Bittering Units" and one IBU
is 1 part per million of isomerized hop oils. Typically this is
measured with a UV spectrophotometer (the stronger the
absorbance, the more oil). One part per million is equivalent
to one milligram in one liter. 100 milligrams would be somewhat
more than 5 drops, assuming 20 microliters per drop and a
density 10% less than that of water. I would expect the solubility
limit in water to be more like 1 weight percent, or 10 grams
(10,000 IBU) in one liter. I say one weight percent because
that's typically the solubility of oily solvents like toluene in
water, and the hop oils are actually more polar.

Ray

No, you are wrong about an IBU being 1 part per million of isomerized hop oils! Though, I was also wrong about the light absorption. It is actually light reflection that is used to determine IBUs.

http://en.wikipedia.org/wiki/International_Bitterness_Units_scale#By_bitterness

In reference to the IBU scale:
"This technique was adopted at the same time as another method based on measuring the concentration (in milligrams per liter; parts per million w/v) of isomerized α acids in a beer, causing some confusion among small-scale brewers.[12] The American Society of Brewing Chemists, in the introduction to its methods on measuring bitterness, points out some differences between the results of the two methods:"

I believe that you are one of the confused homebrewers referenced in the Wikipedia entry.

 

[Sardoman]

If you put aside your choice to do full boils so as to BIAB, do you really notice an improvement in the quality of your beer with full boil since moving from partials?

I wouldn't categorically say that my beer is "better" because I am doing full boils now, but it is different. Take BM's Centennial Blonde recipe for example. That has certainly changed in a good way. (I have only done the extract + grains version) It has a lighter color, more like I expect a blonde to look. The toasty flavors (melanoidins) are greatly reduced now, leaving a cleaner, more well-rounded flavor that allows the hops to have more presence. On the other hand, I actually enjoyed my Oktoberfast ale (partial mash) more when I had made it with a partial boil. The color was very close this year to last year, not that I care so much about color on darker ales, but I missed some of the additional melanoidin character from this brew. Next year I will do a full boil on this again but I will add a touch of melanoidin malt to the partial mash.

In short, I think the full boil has improved some of my brews, and I think I can adjust the recipes to compensate for those brews that were not as tasty when done as a full boil.

I also feel more confident about the sanitary transfer of my cooled wort from the spigot of my BK into my sanitized fermenter via a length of sanitized tubing. Much safer than pouring from a height and topping off with additional water.

 

[el_caro]

Thanks for that info Sardoman

 

[rayg]

No, you are wrong about an IBU being 1 part per million of isomerized hop oils! Though, I was also wrong about the light absorption. It is actually light reflection that is used to determine IBUs.

http://en.wikipedia.org/wiki/International_Bitterness_Units_scale#By_bitterness

In reference to the IBU scale:
"This technique was adopted at the same time as another method based on measuring the concentration (in milligrams per liter; parts per million w/v) of isomerized α acids in a beer, causing some confusion among small-scale brewers.[12] The American Society of Brewing Chemists, in the introduction to its methods on measuring bitterness, points out some differences between the results of the two methods:"

I believe that you are one of the confused homebrewers referenced in the Wikipedia entry.

You have thoroughly confused yourself by taking
a quote out of context from the wikipedia entry.

From "Malting and Brewing Science" vol 2 by Briggs, Stevens and Young
p491:
"In the internationally agreed upon method, degassed,
acidified beer (10mL) is extracted with isooctane
(2,2,4-trimethylpentane) (20mL) and after centrifugation,
the absorbance of the isooctane layer is read at 275 nm
in a 1 cm cell against a blank of pure isooctane when
Bitterness Units (BU) = 50 x absorbance."

and p789:
"In beers brewed from fresh hops bitterness units are
approximately equal to mg iso-alpha-acids per liter."

and p790:
"By TLC the cis and trans iso-alpha-acids were resolved
and shown to account for 88-100% of the light absorption
of iso-octane extracts of beer."

No reflectance involved. These methods have been known
for quite a long time and there really is no point in debating
their existence.

Ray

 

[LVBen]

Are you even reading what you are posting?

"In beers brewed from fresh hops bitterness units are
approximately equal to mg iso-alpha-acids per liter."

IBU measurements are done with light and they are a useful tool for approximating the amount of isomerized alpha acid in beer. It does not give you the ppm of isomerized alpha acids, but it is close enough to be useful for us as homebrewers.

 

[rayg]

Are you even reading what you are posting?

"In beers brewed from fresh hops bitterness units are
approximately equal to mg iso-alpha-acids per liter."

IBU measurements are done with light and they are a useful tool for approximating the amount of isomerized alpha acid in beer. It does not give you the ppm of isomerized alpha acids, but it is close enough to be useful for us as homebrewers.

IBU's have been interpreted by both professionals and
homebrewers as mg/liter of bitter hop oils since forever.
Whether or not they are *exactly* equal is beside the
point. Everyone knows that they can't be *exactly* equal
because there are multiple hop oils involved and the absorbance
wavelength isn't specific for any one hop oil, it's just a useful
average that gets you close to the true value with a single
simple measurement. The original point I was trying to make
was that a partial boil does not prevent you from making a 90
IBU beer, and my original analysis of the amounts involved
stands.

Ray

 

[rayg]

Furthermore, there shouldn't be any problem
with color in a partial boil either, if you think
there is then just add the hops to the water
without extract at the times you normally
would, and then add the extract with 5-10 min
to go, enough to sterilize them.

Ray

 

[Zixxer10R]

I just bought a 41,000 btu turkey fryer and 30qt pot for 49.99 at Meijer. I've been looking for a while and seemed like a good deal.

Did you happen to check Academy before you bought? I got my 105,000BTU burner and a 32qt pot for $39.99. Maybe that deal doesn't exist anymore but i figured i would mention it in case you can return your purchase if Academy still has this.

 

[Zixxer10R]

No, you are wrong about an IBU being 1 part per million of isomerized hop oils! Though, I was also wrong about the light absorption. It is actually light reflection that is used to determine IBUs.

http://en.wikipedia.org/wiki/International_Bitterness_Units_scale#By_bitterness

In reference to the IBU scale:
"This technique was adopted at the same time as another method based on measuring the concentration (in milligrams per liter; parts per million w/v) of isomerized α acids in a beer, causing some confusion among small-scale brewers.[12] The American Society of Brewing Chemists, in the introduction to its methods on measuring bitterness, points out some differences between the results of the two methods:"

I believe that you are one of the confused homebrewers referenced in the Wikipedia entry.

You have thoroughly confused yourself by taking
a quote out of context from the wikipedia entry.

From "Malting and Brewing Science" vol 2 by Briggs, Stevens and Young
p491:
"In the internationally agreed upon method, degassed,
acidified beer (10mL) is extracted with isooctane
(2,2,4-trimethylpentane) (20mL) and after centrifugation,
the absorbance of the isooctane layer is read at 275 nm
in a 1 cm cell against a blank of pure isooctane when
Bitterness Units (BU) = 50 x absorbance."

and p789:
"In beers brewed from fresh hops bitterness units are
approximately equal to mg iso-alpha-acids per liter."

and p790:
"By TLC the cis and trans iso-alpha-acids were resolved
and shown to account for 88-100% of the light absorption
of iso-octane extracts of beer."

No reflectance involved. These methods have been known
for quite a long time and there really is no point in debating
their existence.

Ray

Are you even reading what you are posting?

"In beers brewed from fresh hops bitterness units are
approximately equal to mg iso-alpha-acids per liter."

IBU measurements are done with light and they are a useful tool for approximating the amount of isomerized alpha acid in beer. It does not give you the ppm of isomerized alpha acids, but it is close enough to be useful for us as homebrewers.

IBU's have been interpreted by both professionals and
homebrewers as mg/liter of bitter hop oils since forever.
Whether or not they are *exactly* equal is beside the
point. Everyone knows that they can't be *exactly* equal
because there are multiple hop oils involved and the absorbance
wavelength isn't specific for any one hop oil, it's just a useful
average that gets you close to the true value with a single
simple measurement. The original point I was trying to make
was that a partial boil does not prevent you from making a 90
IBU beer, and my original analysis of the amounts involved
stands.

Ray

Furthermore, there shouldn't be any problem
with color in a partial boil either, if you think
there is then just add the hops to the water
without extract at the times you normally
would, and then add the extract with 5-10 min
to go, enough to sterilize them.

Ray

So tell me fellas, your bickering above has helped the OP with his question in what way?

OP, for what it's worth, i think my beers have improved going to full boils only because i feel like i carmalize the sugars in solution much less so my flavors come out the way I intended them to. The problem with this question is that generally the upgrade question isn't a single upgrade at a time. Most people will get a kit when they buy a turkey fryer because that's how most retailers sell a turkey fryer. Also consider that people who are thinking about full boils probably are looking because they want to make better beer and a full boil is ingrained in this generation's homebrew segment as a surefire way to accomplish that (i won't go into whether or not thats fact or fiction). Hope that helps.

 

[windbreaker123]

I can think of one that's indisputable: bittering potential. You can't make a 90 IBU IIPA with a partial boil. Do you have the equipment to measure actual ibus for bittering? Or is it hear say?

 

[windbreaker123]

would you like to taste my ibus on a partial boil ?

 

[rayg]

So tell me fellas, your bickering above has helped the OP with his question in what way?

I wasn't bickering, I was pointing out the facts. And it
helps the op because one poster said you can't make
90 IBU beers unless you do a full boil, and that's not
true. I doubt very much that partial boils cause more
darkening, but even if it does, all you have to do is not
boil the extract for too long. The only reason to do a full boil
is because you are doing all grain (excluding biab), it's not
because full boils somehow give you better beer.

Ray

 

[Yooper]

I wasn't bickering, I was pointing out the facts. And it
helps the op because one poster said you can't make
90 IBU beers unless you do a full boil, and that's not
true. I doubt very much that partial boils cause more
darkening, but even if it does, all you have to do is not
boil the extract for too long. The only reason to do a full boil
is because you are doing all grain (excluding biab), it's not
because full boils somehow give you better beer.

Ray

But, your "facts" are incorrect as well as out of place in the "beginner's brewing forum".

If you can only isomerize 100 IBUs in a liquid (as the liquid is "saturated" with the oils at that point), and the liquid is 2.5 gallons, and you add 2.5 gallons of water, the limit of IBUs in a partial boil of 2.5 gallons is 50 IBUs.

Still, that's off-topic for this thread and another thread should be started with the new topic.

And I would argue that full boils DO and WILL make better beer over a partial boil, all other factors being equal. Less maillard reactions, less "thickening" and darkening of the wort, and closer to the hops utilization of the corresponding AG batch.

 

[rayg]

But, your "facts" are incorrect as well as out of place in the "beginner's brewing forum".

If you can only isomerize 100 IBUs in a liquid (as the liquid is "saturated" with the oils at that point), and the liquid is 2.5 gallons, and you add 2.5 gallons of water, the limit of IBUs in a partial boil of 2.5 gallons is 50 IBUs.

Still, that's off-topic for this thread and another thread should be started with the new topic.

And I would argue that full boils DO and WILL make better beer over a partial boil, all other factors being equal. Less maillard reactions, less "thickening" and darkening of the wort, and closer to the hops utilization of the corresponding AG batch.

No, you are incorrect, and I don't see how facts can be out of place
anywhere. Are newbies going to implode if I bring up "milligrams" or
"isomerization"?

The solubility of unisomerized alpha acids is ~80mg/L (~80 IBU), but it's
the isomerized alpha acids that end up in beer, and their solubility is
astronomical compared with the unisomerized acids (put it this way:
the molecular structure is similar to ascorbic acid, and ascorbic acid
has a solubility of 330 GRAMS (not milligrams) per liter. The pKa of
ascorbic acid is about 4, similar to acetic acid, but isomerized hop alpha
acids have a pKa of 3, ten times more acidic so even more soluble). The
only limit to IBU's is how much hops you can throw in the beer. The TASTE
limit may be at about ~100 IBU, but the solubility is far far higher.

Ray

 

[Zixxer10R]

No, you are incorrect, and I don't see how facts can be out of place
anywhere. Are newbies going to implode if I bring up "milligrams" or
"isomerization"?

The solubility of unisomerized alpha acids is ~80mg/L (~80 IBU), but it's
the isomerized alpha acids that end up in beer, and their solubility is
astronomical compared with the unisomerized acids (put it this way:
the molecular structure is similar to ascorbic acid, and ascorbic acid
has a solubility of 330 GRAMS (not milligrams) per liter. The pKa of
ascorbic acid is about 4, similar to acetic acid, but isomerized hop alpha
acids have a pKa of 3, ten times more acidic so even more soluble). The
only limit to IBU's is how much hops you can throw in the beer. The TASTE
limit may be at about ~100 IBU, but the solubility is far far higher.

Ray

Ray, you are bickering. Definition here:
Noun 1. bickering - a quarrel about petty points.
1

: to engage in a petulant or petty quarrel

Now, by definition, you have bickered along with most of the other responses in this thread. Quite frankly, i haven't seen the OP respond back with a "thanks" or anything of the sort and it's because some one got set off with the famous IBU ceiling argument and we began a swift downward spiral.

Yooper's right, the OP doesn't really need to be concerned with the IBU ceiling at this point unless he/she speaks up and says that's the major concern with their original question (it's not, in case you're wondering). At this point i'm glad i'm not a moderator because i would have shut this thread down in a hurry, as petty arguments are SO no helpful to anyone. All you do is come off sounding like an a$$hole, but yet somehow, still lack any significan't contribution to the conversation.

Can we please get back on topic here? We can have the IBU ceiling discussion in the Brew Science forum if you still feel like you need to get something off your chest Ray.

 

[jkarp]

Disagree. No matter how many alphas you pump into your partial boil, you can't exceed ~50 IBU if you dilute it with an equal volume of water. A full boil can potentially achieve a theoretical doubling of utilization over a half-volume boil.

Not true and there's hard data to prove it. Basic Brewing did partial / full boil experiments and sent the finished beer out for lab testing. They saw no difference in IBUs between their partial and full boil beers.

That said, IBUs are damn complicated and there are many factors involved, most of which home brewers blindly ignore and take their brewing software IBU calculation as gospel.

 

[jkarp]

Sorry Zixxer10R and yooper but you're both way off target here.

When the OP asks if there's any difference between full and partial boils, and by the 3rd and 4th reply things are running off track from known IBU science, rayg's response was perfectly on topic and reasonable.

There's no point in leading OldBrewPhotography into thinking he can't make an IPA with a partial boil. We all know better than that.

 

[Rev2010]

All you do is come off sounding like an a$$hole, but yet somehow, still lack any significan't contribution to the conversation.

Wow, just read through this whole thread and I can't see anywhere that Ray comes off as an "a$$hole". Look at the situation here, YOU are the one insulting him! He has responded extremely intelligently and so far it seems that people that just aren't up to understanding his points are getting angry.

Man, some people get waaay too worked up in some threads.


Rev.

 

[cadarnell]

I do about an 85% boil I guess .. I usually start the boil with the amount of finished beer I want to make, and then top off with bottled water post boil .. I'm actually not sure I'll ever change, as the beers I have made this way taste just as good as the few I haven't topped off.

Doing it this way lets me get it boiling faster, and chilled faster. Also, I can do a pre boil gravity check and then make some boil length and hop addition adjustment to help hit my numbers, if needed. Good Luck.

 

[ncbrewer]

I've found the hop utilization debate very interesting and educational. Maybe a cross-reference thread could be put in another forum so folks interested in the subject would know to look in this thread.

 

[rayg]

If you can only isomerize 100 IBUs in a liquid (as the liquid is "saturated" with the oils at that point), and the liquid is 2.5 gallons, and you add 2.5 gallons of water, the limit of IBUs in a partial boil of 2.5 gallons is 50 IBUs.

If you have a limit of 80 mg/L of UN-isomerized
hop oil, this has no effect on the final amount of ISOMERIZED
hop oils. That is because as each molecule of un-isomerized
oil is isomerized, it makes room for another molecule of
un-isomerized oil. The practical limits on IBU's are

a) how much hops you can pack into a boil volume.
Obviously you can't put 100 pounds of hops into
a 5 gal boil (or 2.5 gal). What you could do though
is remove the hops after say 30 min, and replace
them with fresh hops, rinsing the old hops and putting
the rinse back in the kettle to keep the volume up.

b) the rate at which the ISOMERIZED hop oils degrade.
If you boil long enough without adding more hops,
eventually you will convert the oils to something
else entirely. As long as you keep introducing
new hops into the wort, the rate of production
will exceed the rate of degradation, but there
is a *practical* limit to how much hops you
could put in the beer, it's not a question of
boil volume.

Yes, there is a real limit to how much isomerized hop
oil you can put into a batch, but that limit will be
more like 300,000 IBU's for a 5 gallon batch versus
150,000 IBU's for a 2.5 gallon batch, but the only
way to do that would be to add isomerized hop oils
from a bottle of hop oil.

Ray

 

[rayg]

Wow, just read through this whole thread and I can't see anywhere that Ray comes off as an "a$$hole". Look at the situation here, YOU are the one insulting him! He has responded extremely intelligently and so far it seems that people that just aren't up to understanding his points are getting angry.

Man, some people get waaay too worked up in some threads.


Rev.

Thanks and thanks to jkarp also for coming to my
defense. There seems to be an awful lot of resentment
around here whenever someone tries to prick the balloon
of some suburban brewing myth. It's funny that when
someone in the beginner's forum asks a simple question,
it's ok to respond with some nonsense, but an accurate
scientific answer is not allowed! Just how is the beginner
supposed to learn? Oh, I get it, he's supposed to
follow the myths and then find out the hard way that
they aren't true, but wouldn't that negate the purpose of the
beginner's forum? Or have I misinterpreted the beginner's
forum and is it actually the place where only beginner's
argue or offer their misinformation to each other?

The claims about me "bickering" are just too funny!
I've tried to offer factual information and others
start name calling or mischaracterizing what I say,
making it personal, and I'M the one that is claimed
to be bickering!

The op asked "Do full boils make that much of a difference
over partial boils?", the short answer to a beginner
should have been "No". But of course some posters
begin adding their 2 cents and I felt I was helping
out by correcting some of the myths. Nobody complains
about the misinformers though.

The Journal of the Institute of Brewing is making
all its papers available for free temporarily, you
can read about utilization to your heart's content.
http://www.scientificsocieties.org/jib/

Ray

 

[jkarp]

I definitely expected better from Yooper but perhaps she was having an off day. It happens.

Anyway, good stuff rayg.

 

[Yooper]

I definitely expected better from Yooper but perhaps she was having an off day. It happens.

Anyway, good stuff rayg.

An "off-day?" Seriously? Because I still believe the science behind hops oils isomerization? And standing by that belief that has been published by noted brewing scientists?

I did NOT resort to namecalling, insults, etc. I can still stand by beliefs based on the scientific papers I've read, scientists I've spoken to, and my own experiences without resorting to accusing others of having an "off day".

 

[phatrat]

You hop heads are ruining this thread. I read this thread to get info on partial vs. full boil. I had to endure 5 pages of blah blah about how much hop oils you can stuff into your brew.

My question is --> I sometimes do keggle brewing in the winter outside in Michigan. I was thinking maybe I was being stupid only making 10 gallons of extract beer when I could add another 5 gallons of cold water at the end. This would allow me to produce 15 gallons of beer. My major reason for reading this thread was to determine if adding water at the end of a extract brew makes worse beer. I don't care about sterlization techniques or how much hop oils to make some quacked out high hop Mr. Clean lemony fresh brew. I swear there are homebrewers who would rate a can of extract with 750ml of vodka poured into it one of the best beers they ever drank. Why do so many people think ultra high hops...or extra thick stouts...are what define a good beer. How about well balanced brews that define classic styles that have been served up for century's.

 

[zdenali21]

I have just ordered the NB Deluxe Starter kit. I bought a 5.5 gallon brew pot as well. The recipe ask for 2.5 gallons to be boiled for the wort. If I boil 3.5 or even 4 gallons, will it improve the taste on the beer. I am starting with the NB American Wheat (extract).