New BYO Aussi brewing article

[Fatgodzilla]

Sorry to drag you all back to the botulism argument, but you are all missing one really important fact: the cubes used to store the wort are made of polyethylene, and polyethylene allows a lot of oxygen through it. So, once the wort is cooled, oxygen will to permeate the wall of the cube, dissolve in the wort, and the wort will become oxygen-saturated in a matter of days.

I did some math based on the oxygen transmission rates posted here - http://www.flextank.com.au/PDF_Files/2-Year-Update.pdf and came up with a transmission rate of about 2 ppm per day based on a full 20 liter cube, 27 cm on a side. So, in 4 days, enough oxygen could get in to saturate the wort. Voila, no spore growth since an anerobic environment is needed. I suspect the rate limiting factor is the diffusion of oxygen through the wort, not the permeation through the cube wall.

By the way, my calculations were based on a 1 mm (40 mil) wall thickness, and I suspect the cubes are less than half that, which increases the amount of oxygen that can permeate in 24 hours.

I surmise that no Aussie homebrewers have botulinized themselves for several reasons, none of which have to do with their robust immune systems... Presence of oxygen, sterilization of the wort by boiling, followed by natural pasteurization as the wort slow cools, and competition by yeast when a true anaerobic environment is created during the first phase of yeast growth.

I'm not sure why the cube use directions suggest minimizing air space, unless it is the originators of the idea didn't know about polyethylene's ability to transmit oxygen. Anyone know why? Fatgodzilla?

Here I am, dragged screaming back to the thread. Gone back to my sources on AHB for some REAL SIMPLE ANSWERS (cos we are homebrewers not scientists or chemists etc)


On the matter of oxygen satuation, the rates calculated may well be true for empty containers, but full containers of wort can't possibly allow that rate. While the container may allow the oxygen flow, what makes you think the wort will absorb it.

Australian reasoning .. fermenters are made with the same material as cubes. If this much oxygen was absorbable through the walls of a fermenter, why oxygenate prior to pitching yeast. Or the New Zealand reasoning .. you can lead a sheep to water, you can't make it drink.

The minimalisation of airspace is a "just in case" attitude. The less air in the cube, the less chance that there is anything in air that can harm you. I have done and others have done a no chill with a largish air head space with no problems - though in these cases I have brewed them asap. Aussie reasoning - you put a hot wort in a fermenter that is too hot to pitch the yeast, you close the lid and wait till the wort is cool enough. As a rule, nothing bad happens tp the wort, but the longer you don't pitch, the odds of problems happening increases. Particularly if you keep opening the lid.

I'm not sure why the cube use directions suggest minimizing air space, unless it is the originators of the idea didn't know about polyethylene's ability to transmit oxygen.

I won't tell them they can't be right if you don't !

More good old fashioned wisdom guys ..

Don't make mountains out of mole hills

If it walks like a duck, and quacks like a duck and has feathers like a duck, its probably a duck.

If it works, good. If it aint broke, don't fix it.

I'll let you blokes rabbit on about botulisma and oxygen permeability - no one has died of botullism due to no chilling and our worts stay fresh in the cube without going off for months. Why, I don't care ! It just does.

Go No Chill !!

Good brewing brothers !

 

[Austin_]

I'm going with the Pol on this. I'm going to try it. I probably won't ferment in the container, but I will definitely go no-chill. Baby steps at this point.

 

[peas_and_corn]

I just got back into no chilling after a while using a CFWC. I had a few reasons for doing so-

1: Australia is in its worst drought in recorded history. Chilling uses a lot of water, and since South Australia (my state) is the driest state in the country... well, I thought that I'd obey the water restrictions for this part of brewing

2: I'm a really lazy man and it's just so simple to no chill then aerate in the morning. No buggering around making sure that the chiller was at maximum efficiency. Additionally, on a 30C+ day, the tap water was inevitably quite warm and didn't really bring the wort down to a very cool temperature anyway and I had to quasi-no chill.

3: I no-chilled before getting the chiller with no problems. My LHBS actually recommends it to starting AG brewers since it is an easy method.

 

[effectrammstein]

I'm from Adelaide, South Australia, like peas and corn.

I no chill whenever I don't have any late hop additions, because I am one of the australians that isn't totally on board with no chill (solely because of the aroma) - I find that because of the longer time the wort is at a higher temperature it slightly changes my late addition hops into bittering hops.

The amount of water that is used for my counterflow chiller is excessive compared to the amount of beer I get from brewing. All my neighbours that are putting buckets in their showers (its a drought and they use the water on their garden) get quite upset when they see all that water going to waste (even though I am putting it onto the garden).

We can actually buy fresh wort kits in australia, where the wort is pre-boiled and hopped so all we need to do is aerate and pitch some yeast. Not one case of botulism has been recorded. In fact I don't even know why botulism rears its ugly head with regards to no-chill. It takes a good year or two for it to happen...it would puff the whole no-chill container up - and we all know not to use it...but no homebrewer leaves their no-chill for more than 6 months. We like to drink our beer - not store it unfermented. There are so many products that you buy in america with the same packaging, but no alarm bells for botulism are gong off - think about the marked down cans of food at your supermarkets.

Give it a go - I would try it with german malts though (only because I have only done no chill with both australian and german malts - no amercian)

Cheers

 

[remilard]

We can actually buy fresh wort kits in australia, where the wort is pre-boiled and hopped so all we need to do is aerate and pitch some yeast. Not one case of botulism has been recorded.

We have no idea how these are processed.

In fact I don't even know why botulism rears its ugly head with regards to no-chill. It takes a good year or two for it to happen...it would puff the whole no-chill container up - and we all know not to use it...but no homebrewer leaves their no-chill for more than 6 months. We like to drink our beer - not store it unfermented. There are so many products that you buy in america with the same packaging, but no alarm bells for botulism are gong off - think about the marked down cans of food at your supermarkets.

Commercial packaged foods have a targeted 12 log(10) reduction in C. Botulinum spores meaning for every 1,000,000,000,000 spores at the beginning of processing, one remains at the end. As you are aware, even with this standard the elimination of C. Botulinum has failed in practice.

75 minute wort boils achieve a 3 log(10) reduction in C. Botulinum spores meaning that for every 1,000 spores at the beginning of the boil, 1 is alive at the end. Clearly this is a phenomenally lower standard rendering any comparison between no chill home brewing and commercial food processing worthless.

Clearly many people believe that there is no danger inherent in no chill and that may be the case. It is my observation, however, that nobody posting here understands why or can refer me to anyone who understands why.

If you want me to just shut up and share in your beliefs without questioning them, then that is why HBT should have a separate forum for scientific discussions because that is precisely the opposite of the aim of science.

 

[Kaiser]

Fatgodilla, Effectrammstein, Peas_and_corn,

We are not out to show that you are totally nuts and that you don’t know what you are doing, I for myself find the no chill concept a great idea to save water and it is likely to work with many brewer’s schedules. I also don’t think that there is a botulism problem if you cool the wort overnight or even store it for a day or two just because C.B. needs some time to grow. My only concern was with the idea of longer storage.

And if we can find someone who is sufficiently knowledgeable and sufficiently unbiased to give us an answer whether or not there is a risk of botulism and how that risk changes depending on the length of storage it can only help the adoption of this process. Even if we shut up about this here, it will pop up somewhere else and many brewers reading it and not seeing a definitive answer won’t even give it a try b/c just the thought of getting botulism will scare them away.

That’s why I feel we need to get to the root of this and find an answer. This answer will also apply to canned starter wort. Up to this point we have been told to pressure can starter wort.

And I can’t help reading your posts with an Australian accent

Kai

 

[bakins]

I generally ferment in HDPE buckets and my beer isn't oxidized. I'm not sure why a few days stored in an HDPE "cube" would matter. But, I willing admit I don't know anything about oxygen absorption or botulism...

 

[The Pol]

I FWH most of my beers, so it will be interesting to see what happens to my bitterness. Since, of course, FHW'ing generally moves your late edition hops, forward to FWH.

This experiment will be in full effect next week! Oh darn, an excuse to brew.

 

[AiredAle]

fatgodzilla,

I am a homebrewer, and I’m a chemist as well, so part of the fun of homebrewing for me is trying to sort out why stuff works from a chemical point of view.

I am not disputing that the no chill process works, or suggesting that you are all doing something wrong by using it. In fact I was offering some evidence to this discussion that the wort was not being stored in an oxygen-free environment, and that might help explain why you weren't dropping like flies from botulism.

Regarding how much oxygen wort can absorb through the cube wall:

-Wort in contact with air (20% O2) saturates at about 7ppm (7 mg of O2 in 1 liter of wort). Pure water saturates at about 8 ppm at 25 Celsius.

-The calculation I made for the amount of O2 that could pass through the cube wall showed that a total of about 2 mg O2 per liter of wort (2 ppm) in a 20 liter cube could permeate though the entire cube surface every 24 hours.

-You are right, this will only happen if the O2 is absorbed and distributed in the wort. If the layer of wort in contact with the cube wall is saturated then no more O2 will pass into the cube. BUT, O2 will dissolve in and diffuse through the wort, and will continue to do so until the entire volume of wort is saturated with O2. If the passage of O2 through the wall was the limiting step, this would take 4 days. I doubt it goes that fast, but I don't think it takes too much longer.

-If you store your cooled wort in a HDPE cube long enough, you won't have to aerate it.

By the way, I got my data for O2 diffusion through polyethylene from an Aussie company's website (see my earlier post). That company sells HDPE tanks for aging wine because it does let O2 through, and winemakers want contact with oxygen to help age the wine. My Yank logic tells me that if O2 diffuses through the wall of a HDPE tank for wine, it will diffuse through the wall of a HDPE cube containing beer wort as well.

If, as your experience shows, you can keep wort fresh for extended times in a cube, that suggests that the presence of O2 in the wort at room temperature isn't an issue.

So, carry on with no chill, it works for you. I want to understand why it works. Since it saves water and time, if I think I can make the same quality of beer under my brewing conditions, then I might give it a try. But before I do, I need to understand what's going on so I can make my own judgement of what effect it will have on the unfermented wort.

 

[Fatgodzilla]

I am a homebrewer, and I’m a chemist as well,

We have the eternal dilemma.

I am a homebrewer, and I am an accountant as well.

I admire your examination of this matter and am a little in awe of the technical knowledge that yourself and others are putting into these arguments concerning botulism and oxygen etc.

But the accountant in me says, it works, so I don't need to worry about all this technical stuff.

The Australian in me says .. she'll be right mate !

And I can’t help reading your posts with an Australian accent

Kai

That's because I'm typing them in Australian !


Cop ya later !

 

[reviled]

FWIW, im from NZ, and ive pretty much exclusively BIAB'ed and No chilled since I got into AG brewing, done about 30ish brews so far... The most time ive left wort in a cube was 4.5 weeks, im still alive :rockin: Im not a chemist, im not a scientist, but my beer doesnt give me botulism, and it definately does not oxidise in the cube...

To me, I think the best thing about no chill which hasnt been mentioned, is, not only does it save time and precious water, but that you can do double batches, say 40litre batch, cube 2x20litres, ferment one the next day, and store one away to ferment when the first one is finished or whenever you feel like it... Same amount of time to brew, double the amount of wort. Awesome!

 

[The Pol]

My "no chill" container is also doubling as my primary fermentor.

I plan to take a little of my mid lauter wort and cool it to make a starter.

Then after the boil, drain my keggle to my HDPE "fermentor"

After 24 hours of cooling, toss my starter in and install an airlock.

It will be nice to not have to hook up a chiller, switch the bypass on my softener, run gallons of water down the drain... etc.

I plan to whirlpool and let it sit for 15 mins or so prior to running it off into my HDPE barrel. I also use leaf hops and a homemade hop stopper, so that will also filter out plenty of trub.

I also FHW, so the effect of this on my late addition hops should be minimal, since they dont exist, they have all been moved up to FWH.

EDIT: I have been reading up on Aussie brewing and I really want to get some Riwaka from NZ and try them in a brew soon!

 

[reviled]

My "no chill" container is also doubling as my primary fermentor.

I plan to take a little of my mid lauter wort and cool it to make a starter.

Then after the boil, drain my keggle to my HDPE "fermentor"

After 24 hours of cooling, toss my starter in and install an airlock.

It will be nice to not have to hook up a chiller, switch the bypass on my softener, run gallons of water down the drain... etc.

I plan to whirlpool and let it sit for 15 mins or so prior to running it off into my HDPE barrel. I also use leaf hops and a homemade hop stopper, so that will also filter out plenty of trub.

I also FHW, so the effect of this on my late addition hops should be minimal, since they dont exist, they have all been moved up to FWH.

EDIT: I have been reading up on Aussie brewing and I really want to get some Riwaka from NZ and try them in a brew soon!

Hey mate, good for you for taking the plunge!! All the lagers I do I ferment in my no chill cubes, simply because I cant fit a full size fermenter in my temp controlled fridge, I dont even fit an airlock, just vent the gas every now and then and when its at full fermentation just crack the lid a little.. Never had a problem with this..

 

[carnevoodoo]

So you're filling up your "cube" to the very top so there's no air, and then you're going to ferment in it? Won't krausen be an issue?

 

[reviled]

So you're filling up your "cube" to the very top so there's no air, and then you're going to ferment in it? Won't krausen be an issue?

I only do 20 litre batches, and most of the cubes are actually 20-25 litres, so I normally have headspace but just before I seal up the no chill cube I force all the excess air out and screw the lid on...

Then when fermentation gets active, all the co2 forces the cube back into its normal shape, leaving me with about 3-5 litres of headspace, and I only use em for Lagers which ive never really had a big krausen on..

 

[The Pol]

No, it is a 6 gallon HDPE barrel. Plenty of space.

 

[effectrammstein]

Fatgodilla, Effectrammstein, Peas_and_corn,

We are not out to show that you are totally nuts and that you don’t know what you are doing, I for myself find the no chill concept a great idea to save water and it is likely to work with many brewer’s schedules. I also don’t think that there is a botulism problem if you cool the wort overnight or even store it for a day or two just because C.B. needs some time to grow. My only concern was with the idea of longer storage.

And if we can find someone who is sufficiently knowledgeable and sufficiently unbiased to give us an answer whether or not there is a risk of botulism and how that risk changes depending on the length of storage it can only help the adoption of this process. Even if we shut up about this here, it will pop up somewhere else and many brewers reading it and not seeing a definitive answer won’t even give it a try b/c just the thought of getting botulism will scare them away.

That’s why I feel we need to get to the root of this and find an answer. This answer will also apply to canned starter wort. Up to this point we have been told to pressure can starter wort.

And I can’t help reading your posts with an Australian accent

Kai

I know what you mean, I read all your wikis and posts with your german accent

 

[MacBruver]

That company sells HDPE tanks for aging wine because it does let O2 through, and winemakers want contact with oxygen to help age the wine. My Yank logic tells me that if O2 diffuses through the wall of a HDPE tank for wine, it will diffuse through the wall of a HDPE cube containing beer wort as well.

If, as your experience shows, you can keep wort fresh for extended times in a cube, that suggests that the presence of O2 in the wort at room temperature isn't an issue.

This makes a whole lot of sense. From what I've been reading, purely the presence of oxygen in the wort is not enough to cause oxidation, even over long time frames. From how to brew:

The generally accepted temperature cutoff for preventing hot wort oxidation is 80°F.

Now the wort IS going to be exposed to some oxygen when it's above 80F, but it's not much at all- and it's naturally at a state where it is adverse to absorbing oxygen due to its higher temperature. It would take some concerted effort to aerate it WHILE it's above 80F to cause this oxidation to happen, is what I'm thinking. Carefully racking it into a cube and sealing the sucker up is not going to be enough for it to be a real problem.

So, in the end, you will have a cube of wort that is completely saturated with oxygen, and NOT oxidized. And when you think about it, those are exactly the conditions that you look for when you are pitching yeast into it. I'd say if you were to wait to use "cubed" beer, 4+ days would be preferable due to this.

One thing you would want to ensure though is that the wort is stored somewhere where the temperature is not going to be above 80F... but I think that would be a good idea anyway.

 

[The Pol]

Mine will be stored in a temp controlled environment at 65F, well for 24 hours.

 

[MacBruver]

Mine will be stored in a temp controlled environment at 65F, well for 24 hours.

If all my wild-ass speculation is correct, you should probably aerate before you pitch, if you're only waiting 24hrs... are you planning to?

 

[Danek]

If there is a mass outbreak of botulism poisoning in Australia, please let it be before the Ashes. We need all the help we can get.

 

[reviled]

Also - On the botulism thing, not my links but still interesting none the less, 1ppm equals about 1IBU,

botulism hates hops.

"The present invention relates to the discovery that hop extract is useful as an antibacterial agent against the dangerous pathogens Clostridium botulinum, Clostridium difficile, and Helicobacter pylori at levels below that at which a flavor from the acids contained therein is objectionable. More specifically, a process and associated product is described herein, comprising applying a solution of hop extract to a food, beverage or other medium so that the final concentration of hop ingredients is about 1 ppm or higher in order to inhibit the growth of Clostridium botulinum, Clostridium difficile, and/or Helicobacter pylori.
"

Treating or preventing illness growth of Clostridium difficile - Patent Review 6623775
Antimicrobial activity of hops extract against Clostridium botulinum, Clostridium difficile and Helicobacter pylori - US Patent 6251461 Claims

 

[The Pol]

If all my wild-ass speculation is correct, you should probably aerate before you pitch, if you're only waiting 24hrs... are you planning to?

Yes... I am letting it chill for 24 hours in a 65F environment. THEN, I am beating it the hell up. Tossing in a starter. Watching it bubble. Drinking it. Posting my findings here.

I am treating it like any other brew, just no chilling it.

 

[remilard]

Also - On the botulism thing, not my links but still interesting none the less, 1ppm equals about 1IBU,

I'm interested in how you equate ppm of beta acids to bitterness in beer.

It is known that beta acids are not particularly soluble in wort, this is why the are ignored in every calculation of bitterness I have seen. What I can't find in the resources I have is exact figures on how soluble beta acids are, just references to the fact that they are so poorly soluble as to be ignorable in calculating bitterness.

If you can justify your claim above then I will gladly agree that C. Botulinum will not grow in hopped wort, assuming the claim in the patent application is correct. However, I suspect you are making some unrealistic assumptions about the solubility of beta acids in wort or perhaps confusing alpha acids for beta acids.

 

[MacBruver]

Yeah, the problem with those patents is this:

6. The method of claim 1, and including the step of adding a surface active agent to a solution in order to solubilize said hop extract prior to adding said hop extract to said food or beverage product.

They add some type of surfactant to get the beta acids in solution.

 

[reviled]

I'm interested in how you equate ppm of beta acids to bitterness in beer.

It is known that beta acids are not particularly soluble in wort, this is why the are ignored in every calculation of bitterness I have seen. What I can't find in the resources I have is exact figures on how soluble beta acids are, just references to the fact that they are so poorly soluble as to be ignorable in calculating bitterness.

If you can justify your claim above then I will gladly agree that C. Botulinum will not grow in hopped wort, assuming the claim in the patent application is correct. However, I suspect you are making some unrealistic assumptions about the solubility of beta acids in wort or perhaps confusing alpha acids for beta acids.

To be honest mate im not too sure, I got that info from the AHB website and thought some people on here might find it usefull..

 

[The Pol]

If I die, I die, then yall can stop speculating. Everyone wins!

 

[remilard]

If C. Botulinum can not grow in no chill wort, then beer drinkers will not get botulism and die.

implies

If beer drinkers do not get botulism and die, C. Botulinum can not grow in no chill wort.

Which logical fallacy did I commit?

 

[The Pol]

If C. Botulinum can not grow in no chill wort, then beer drinkers will not get botulism and die.

implies

If beer drinkers do not get botulism and die, C. Botulinum can not grow in no chill wort.

Which logical fallacy did I commit?

I dont feel comfortable talking about fallacio here...

 

[peas_and_corn]

It's the same logic that says

All dogs have four legs
My cat has four legs
Therefore my cat is a dog

 

[The Pol]

Where can I get some Riwaka??

 

[PoMo]

Yes... I am letting it chill for 24 hours in a 65F environment. THEN, I am beating it the hell up. Tossing in a starter. Watching it bubble. Drinking it. Posting my findings here.

I am treating it like any other brew, just no chilling it.

I'm very interested in the results of your experiment. I'm a member of the Illawarra Brewers Union (the IBUs ) who were the club that popularised this method amongst the Aussie brewers. Most of our members (including the FatGodzilla fella posting in this thread) use no-chill almost exclusively. I have seen a copper coil or two around the place, tho most of them have been covered in oxidation since the drought started. There have been thousands of batches of no-chilled beer produced by our members, one of whom also produces "wort packs" commercially. So far none of us has died of botulism, tho this doesn't, of course, prove that C. botulinum cannot spawn in wort. Perhaps we're lucky, perhaps there is something about the pH, O2, gravity or hop content of wort that inhibits botulinum, perhaps our warm temperate climate means we have a lower incidence of botulinum in the environment?

One bit of advice, if I may, if you're using American malt in your brew, give it an extra long boil. It is my understanding that American malt contains more DMS precursors than EU or AU malts, so you don't want DMS to be forming in the cube while the wort is still hot.

 

[Kaiser]

We would need some biologists who can run these tests in a lab: Can C. Botulinum grow in hopped wort?

It wouldn't be a difficult one to run but it is not the kind of experiment I'm going to make in my kitchen mainly b/c I would need a viable culture of C. Botulinum.

I'm amazed that none of the brewing books on Google books say anything about C. Botulinum. Either an indication that it is not a problem at all or that it has so far not been considered as a problem.

Kai

 

[Fatgodzilla]

If there is a mass outbreak of botulism poisoning in Australia, please let it be before the Ashes. We need all the help we can get.

After we put this South African uprising to bed, we are coming after you Poms ...

(for you uneducated lot, of course we at talking CRICKET !)



It's amazing this little conversation on what I think is a rather trivial matter has taken legs across three continents. Next time Australians make a new popular brewing method , we aint gonna tell nobody !

 

[remilard]

We would need some biologists who can run these tests in a lab: Can C. Botulinum grow in hopped wort?

It wouldn't be a difficult one to run but it is not the kind of experiment I'm going to make in my kitchen mainly b/c I would need a viable culture of C. Botulinum.

Kai

I'm not even sure if the (US) Federal Government has an interest in amateurs performing these experiments, since botulinium is a potential biological warfare agent. On the off chance you got caught trying to produce it, they might not be interested in why.

But I agree, for a qualified biologist this should be trivial.

Don't you have access to the Journal of the ASBC and maybe German Journals? Maybe we are trying to reinvent the wheel. Unfortunately my local University Library does not carry brewing (or Food Science) Journals so I'm at a dead end.

 

[remilard]

I'm amazed that none of the brewing books on Google books say anything about C. Botulinum. Either an indication that it is not a problem at all or that it has so far not been considered as a problem.

Kai

I thought about that myself, however this would never be an issue with an commercial brewing practice I am aware of.

Saying "on the off chance that you choose to hot pack wort and leave it sitting around for a while...." in a professional brewing text would be a bit absurd.

 

[The Pol]

In reference to the boil comment... I always boil for 90 minutes, since it is essentially free.

 

[remilard]

See Fix, An Analysis of Brewing Techniques. With ale malt and an ale fermentation you can not possibly get detectable DMS in the beer regardless of how you chill the wort.

 

[PoMo]

See Fix, An Analysis of Brewing Techniques. With ale malt and an ale fermentation you can not possibly get detectable DMS in the beer regardless of how you chill the wort.

This is a beautiful thing.

On the botulism thing... I've just come across this:

"Microbiology, B.D.
Davis, R. Dulbecco, H.N. Eisen and H.S. Ginsberg, 3rd Ed. 1980."

"Most clostridia produce large amounts of gas (mainly Carbon dioxide and
Hydrogen)."


From a post here:
HOMEBREW Digest #2345 Thu 13 February 1997

So if the cube blows up like a balloon, toss it.

 

[The Pol]

I will be really pleased if I can "no chill" and use that same vessel to ferment in. It will save a lot of time and cleaning of vessels. I also like the fact that the 6 gallon HDPE container has a nice strong handle on it!

Pol