Define "BOIL"

[Chairman Cheyco]

What kind of isomerizations are we talking about here? I can understand needing mechanical assistance to emulsify the oils in the water, for instance, but isomerization is a chemical reaction. I'm not knowledgeable of the mechanism of these reactions, but isomerization is usually intramolecular, although I can certainly acknowledge the possibility that these molecules are helping each other isomerize, in which case agitation may help bring them together at a higher rate.

As far as I know, it is the actual collision which speeds the process.

 

[andylegate]

Just wondering here after reading this thread ------ how many of us here actually took chemistry in high school at least? I started busting out laughing as I was reading because homebrewing (at least to those of us that catch the addiction of it) seems to have a way of making all of us become amature/experts in chemistry!

Seriously though, I work with electronics everyday where I work, repairing equipment for cable companies. Over 20 years of experience and I know I can sit here and spout of many things that would confuse your average man.
I never took chemistry, yet at the same time, while learning this hobby, I've learned more and more in this field, to the point that I was able to actually FOLLOW and UNDERSTAND what was being said in this thread!!
If I'd read this several months ago I would have been VERY confused!

 

[marshman]

So, regardless of fast boil, slow boil, nuclear physics and brewmeister chemistry, merely being reeeeeal hot wort is NOT the same as boiling wort.

Thanks, guys.

 

[andylegate]

So, regardless of fast boil, slow boil, nuclear physics and brewmeister chemistry, merely being reeeeeal hot wort is NOT the same as boiling wort.

Thanks, guys.

ROFLMAO!!!!!
Yah, Some of my questions have made answers like this! But it's always better to get all sides of the story......well.....sometimes it is!!

I do most of the cooking and all my cook books say "Rolling Boil" and all they mean is that by getting the "mixture" whatever your mixture might be to a "Rolling Boil" is so that things in the mixture mix well and infuse.
But listen to the guys on here, they've all been doing this awhile and know what they are talking about........MOST of the time anyways......heheheheh ....

 

[MattD]

Just wondering here after reading this thread ------ how many of us here actually took chemistry in high school at least? I started busting out laughing as I was reading because homebrewing (at least to those of us that catch the addiction of it) seems to have a way of making all of us become amature/experts in chemistry!

Seriously though, I work with electronics everyday where I work, repairing equipment for cable companies. Over 20 years of experience and I know I can sit here and spout of many things that would confuse your average man.
I never took chemistry, yet at the same time, while learning this hobby, I've learned more and more in this field, to the point that I was able to actually FOLLOW and UNDERSTAND what was being said in this thread!!
If I'd read this several months ago I would have been VERY confused!

Hah, I just reread my earlier post and realized that I was assuming a fair bit of familiarity with the subjects I was talking about. Not that it's particularly complicated, but I guess I know very little about brewing, and plenty about chemistry and heat transfer, so I jumped on the chance to talk about something I know It's an interesting question though, I'm new on these boards so I don't know anything about anyone's background. Here's mine, I'm currently in 1st year of med school, did a B.S. in mechanical engineering, and worked for a brief period in the nuclear power industry. I've been homebrewing for almost a whole week now, and look forward to bottling a batch someday soon! So there, now you know what to believe when I talk about it and what to take with a grain of salt What about the rest of yall?

 

[dougjones31]

I am sorry you guys are confused. The "Hot Break" starts forming when you notice the foam start to rise on top of the wort before the boil. The foam is the proteins that are coagulating after absorbing energy from the steam that is in suspension in the hot wort. These proteins hang around until the rolling action of the boiling wort allow all the proteins to clump together.....then the "Hot break" ends when the foam breaks.


So some of the things posted in this thread are correct but most are wrong when you are talking about this process.

The hot break begins at the begining of the boil,
anyone unclear on this should bring an all grain
(extracts have small hot breaks) beer just to
boiling and then turn the burner down to observe
the floculation of proteins. IMHO no hops should
be added untill a hot break occurs as hop introduce
nucleation sites that would otherwise be started
by the larger proteins. This will give a brighter
beer. By the way the hot break happens when the
larger protiens come in contact with the interphase
between steam and wort cooking them just as blood
will form a solid when heated. I've seen flocs
the size of dollar bills in my 40-gal brew system
allways at the begining of the boil.


Now you have to grasp the concept of Hot Break only being half of the battle. The rest of the proteins and tannins, that never clumped together in the hot break, come out of suspension during the "Cold Break". The "Cold Break" is best acheived by dropping the temp of the wort really fast. This dropping of the temperature robs the wort of energy. When this happens the proteins and tannins that were being suspended by the energized hot wort are allowed to precipitate out of suspension.

 

[dougjones31]

So....a boil is a boil. Once the surface tension of the liquid is low enough, steam starts to rise up out of and through the liquid. That is a boil.

Once steam starts forming, the Hot Break starts happening. It really does not matter how hard your boil is....the hot break will happen.

I guess, if anything......the harder the boil, the less effective the hot break is. If you consider the energy that is introduced to the wort, I think that maybe some of the protein may stay suspended because of the extra energy that is introduced in a fast boil. That would make the Cold Break more important in that batch.

Hot Break and Cold Break are teammates. When one works real hard the other can be lazy. And when one is lazy the other has to work real hard to make up for it.

 

[boo boo]

Well for a start hot break continues all the while you are boiling your wort, not only at the begining.
I do agree that you should hold off on adding hops until you have a good hot break formed, although some say to add a tad just to break the surface tension of the wort to minimumize a boilover. I don't do this as I add foam control to keep my less-than-optimum-size pot from boiling over.

I think the harder the boil the better the hop ultization of AA's for bittering.

OT As for people who don't seperate the trub when it goes to the fermenter.....what is the point of making sure you get cold break in the first place?

To me, a good rolling boil is what I do.

 

[Desert_Sky]

OT As for people who don't seperate the trub when it goes to the fermenter.....what is the point of making sure you get cold break in the first place?

Isnt a small amount of cold break desirable in your fermentor? Ive read somewhere about amino acids that provide some nutrients for the yeast or something.

 

[dougjones31]

The proteins from the Hot Break or Cold Break do not have to be seperated out when you tranfer to the fermenter. They will settle out in the primary. Once they "break" they will come out of suspension and will settle out on their own. But they have to break or they will remain in suspension.

I am also a believer in the yeast benefits of this protein/amino acids being in the fermenter.

 

[boo boo]

I agree that some is needed for healthy yeast to eat, but the majority isn't needed and enough will make it into my fermenter without me adding all of it.
Break material AFAIK will reabsorb into the wort if not removed before the primary.

Now I could be all wrong on this but to the best of my knowledge this is so.

 

[AdIn]

I read somewhere that too much break material in primary represent easy food for bacteria which you want to avoid.

 

[dougjones31]

"Hot trub is that part of the break that occurs during the boil and is mostly proteinaceous; cold trub, which consists of proteins and protein-tannin complexes, is formed as the wort cools and the beer settles (1). Although most amino acids are assimilated by the yeast, remaining proteins should be removed because they later react with polyphenols, resulting in colloidal instability (haze). The elimination of all non-amino acid proteins is not warranted or even desirable, however, because they are essential for giving the beer full body and head retention."


A little quote from Ron Barchet. And NO, the hot break and cold break protein will not absorb back into the beer if you leave them in the fermenter. As you can read, the amino acids are used up by the yeast. The Proteins which do not settle out, do not settle out because they are very small and float easily. These small proteins would not strain out even if you tried. These very small proteins are the cause of Haze. We all know that that is not a death sentance for beer.


Now there is a huge difference in all-grain and extract brewing when Hot Break and Cold Break is concerned. Extracts already have a large percentage of the proteins removed during manufacturing. All Grain brewer must take time to skim the brew pot and try to remove as much hot trub as possible. It has been shown that quicker, less-intensive mashing routines yield worts containing more trub. Conversely, triple and double decoction mashing produce worts with considerably less trub, because the mash boiling process and the extended protein rests of such mashes maximize the breakdown of proteins and the removal of trub before the kettle boil. But... There will always be some that makes it into the fermenter because the proteins are usually 10-50 microns in size and a strainer or grain bed will not get them all.

What do we do to get rid of the left over hot break material that is in our wort? Well that is what a cold break is for. All the cold break is is the step for removing the smaller floating proteins. Cooling the wort quickly causes them to fall to the bottom of the pot, where you can siphon or pump from above the trub leaving most of it behind.


But then again there are always going to be leftover proteins that make it into the fermenter.


What do we do to make these leftover hot break and cold break proteins precipitate to the bottom of the fermenter?

That is where we use Hop Backs or whirlpools to get the rest. Or is it worth the trouble? I don't think it is worth the trouble. I prefer to use Irish moss or chillproof to help the proteins precipitate out.

If you are really anal you could use a 1 micron filter when you transfer from the brewpot to the primary....that will remove the protein. The thing is that most people filter after fermentation. Why? I feel that they want to leave the amino acids to help the yeast. I have done it both ways and I cannot tell the difference. I brewed 2 identical batches and purposely left all the break material in one and omitted any haze removers. One ended up hazed and one was clear. In a blindfolded taste test, I concluded that there was no difference in taste. I was looking for bitterness caused by the proteins. Some experts say that they can cause bitterness and poor head retention and other say absence of them will cause poor head retention. I did not see it either way.

I weigh the amount of effort required with the results. I see no need to go through a bunch of trouble to try to remove all the hot and cold break.


Now as a side note. I left the hazed beer in the keg and refridgerated for 2 months and then tapped it. The beer had cleared. And a second unblind taste test between the 2 beers was unable to tell the difference. I concluded that the hot and cold break proteins only affect the beer by adding haze. Which can be overcome with additives and time. No affect on the taste was seen. Now I will admit that this test was limited, there may be styles of beer whos taste is affected. The verdict is still out. But for my house brew....A Brown Ale, there is not difference.