Usa's New Fascination With No Chill

[Fatgodzilla]

I go to the US site HomeBrewTalk for a different look at how the other mob does things. The recent BYO feature on Australian brewing opened a thread about No Chill which I got into. Two major concerns the Yanks have which I have never thought of is botulism and now why a cube doesn't allow too much oxygen in. Below is a post that someone here will have an idea of what this guy is asking me. All sane and not Off Topic comments would be considered.

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?

 

[reviled]

A few things, I know that cubes do let in a small amount of oxygen over a long amount of time, but come on, enough to completely saturate the wort?? I doubt it, specially seeing as when you completely squeeze oxygen out of the cube the shape changes, if oxygen was getting back in there surely the cube would return to a 'cube' shape??

And botulism, I know nothing about, I think we need to come down to what causes botulism? And how this would be directly related to no-chilling?? I mean, what is it that causes botulism from no chilling that wouldnt occur in a normal chilling brew. Ive no chilled about 30 batches and i dont think I have botulism?? :huh: I dunno, maybe I do :lol:

 

[reviled]

Taken from wikipedia

"Normal symptoms include dry mouth, double and/or blurred vision, difficulty swallowing, muscle weakness, drooping eyelids, difficult breathing, slurred speech, vomiting, urinary incontinence and sometimes diarrhea"

Isnt it funny how alot of those symptoms seem to be normal symptoms of drinking alcohol (ok maybe not as intense but still)

 

[fraser_john]

The oxygen is dissolved, so not sure whether that would make a difference to the cube shape??? Dunno enough about chemistry to properly comment.

May Dr.Smurto can help.....

 

[white.grant]

I thought squeezing the cube to limit the headspace was to reduce the possibility of infected wort from airborne yeasts or other nasties.

cheers

grant

 

[reviled]

The oxygen is dissolved, so not sure whether that would make a difference to the cube shape??? Dunno enough about chemistry to properly comment.

May Dr.Smurto can help.....

Im not a scientist either so im probably wrong

But anyways, a PET bottle when carbed up, wont lose co2 untill about 9-12 months, and it happens slowly... So why, would Co2 escape mega slow, yet oxygen can get in over a period of days??

Just a thought..

 

[braufrau]

Oh no! Not botulism and no chill again! again! again!
It was done *to death* (no pun intended) on the original no chill thread.
Please don't start Darren up again.

Although .. no one mentioned permeability of the cube to oxygen, that's novel, I'll admit.

 

[mika]

Botulism thing been done to death on this forum before. Darren (IIRC) was/is the driving force behind that argument. Whatever the argument, it doesn't happen. Enough people on here no-chilling to de-bunk that.

My understanding was that the oxygen was excluded so that the hot wort was in contact with the walls for sanitisation as well as preservation.
People have argued about the permeability of plastics and their suitability for fermenting in for ages, I thought the cubes were made from the same plastic the fermenters were and there's a lot of people making good beer in plastic fermenters.
Not a very scientific answer, but still valid I believe.

 

[Adamt]

Well... to answer the question... the headspace will contain air and anything else in the air (that probably wouldn't survive the pasteurisation anyway). Very little headspace = very little air = very little chance anything else in the atmosphere is in there. There's nothing wrong with oxygen in the wort if there's nothing there (alive) to grow in it!

As for those calculations regarding oxygen uptake... sounds a little fishy to me. Those numbers only take into account permeability through the plastic, it does not include the added resistance of absorption, and other factors (pressure differences, etc). The best way would be to test for DO in cubed worts.

 

[Adamt]

Im not a scientist either so im probably wrong

But anyways, a PET bottle when carbed up, wont lose co2 untill about 9-12 months, and it happens slowly... So why, would Co2 escape mega slow, yet oxygen can get in over a period of days??

Just a thought..

The CO2 molecule is larger than the O2 molecule so O2 can get through the gaps easier... it's a little more complex than that but that basically explains it.

 

[Fatgodzilla]

Oh no! Not botulism and no chill again! again! again!
It was done *to death* (no pun intended) on the original no chill thread.
Please don't start Darren up again.

Although .. no one mentioned permeability of the cube to oxygen, that's novel, I'll admit.

Thankfully I missed the botulism argument first time around. There I was thinking "dumb Yanks" what would make them think like that.

I tried to use the argument that it works, why worry about the maths. Common sense.

I'm happy with the air space argument. But this permeability issue threw me. I'm an accountant, not a scientist or engineer. I like suck it and see type solutions, not complicated. What do they say on Mythbusters - "I'll take your reality and substitute it for one of my own " , it may not be right, but I like that idea !

 

[Swinging Beef]

The CO2 molecule is larger than the O2 molecule so O2 can get through the gaps easier... it's a little more complex than that but that basically explains it.

Isnt it an "O" molecule, not an "O2"

 

[mika]

Oxygen is always paired up, it's just how it rolls.

 

[RetsamHsam]

Isnt it an "O" molecule, not an "O2"

lol

I thought they were talking about a certain telco :lol:

 

[SJW]

botulism botulism botulism
Where's Darren?
:lol:

 

[Fents]

Its not all about botulism and oxygen.

If i had an unlimited amount of water to play with i would probably chill too but its Australia and here in VIC we are ina SERIOUS drought.

no ones died yet from no chilling.... and a few of brewers have lost a cube to infection via air getting sucked in....i'll take my chances and keep no chilling and leave some water for my kids to hopefully drink unless all our catchments get filled pronto.

 

[jonocarroll]

But anyways, a PET bottle when carbed up, wont lose co2 untill about 9-12 months, and it happens slowly... So why, would Co2 escape mega slow, yet oxygen can get in over a period of days??

I'm not home right now, so I can't check my cubes, but according to that article, the cubes are made of polyethylene, which (for those that can read these) looks like this

whereas PET bottles (Polyethylene terephthalate) is a different substance, which looks like this

Entirely different beasts if I understand correctly - and likely PET could be more resistant to O₂ and CO₂ permeation.

As with most of these discussions, a complete lack of evidence that you can get botulism from no-chilling seems to suggest that it's not really a problem. I would also agree that those calculations mentioned probably don't account for the pressure of the fluid inside the cube. Besides, if the wort was fully oxygen saturated after a few days, shouldn't yeast in the fermenter revert to the aerobic reproductive phase? I shall gladly continue to no-chill.

 

[Ronin]

And botulism, I know nothing about, I think we need to come down to what causes botulism? And how this would be directly related to no-chilling?? I mean, what is it that causes botulism from no chilling that wouldnt occur in a normal chilling brew. Ive no chilled about 30 batches and i dont think I have botulism?? :huh: I dunno, maybe I do :lol:

Botulism is caused by a toin from Clostridium botulinum, an obligate anaerobe (can't tolerate oxygen) that is normally found in soil. It's in the same family as clostridium perfringens (gas gangrene) and clostridium tetanai (tetanus). Which is why you get a tetanus shot after stepping on a nail in the garden.

I'm not a food microbiologist (I'm medical), but I do know that clostridium botulinum can cause the build up of toxins in foods.

I think that the increase in the 'chance' of a botulinum infection is because of the prolonged time the beer is anaerobic after the boil. If you chill straight away then you are also probably aerating and pitching straight away, which means the clostridium can't grow. Again I'm a medical microbiologist (more of an immunologist really but that's OT).

I'm of the opinion that if the organism hasn't infected a lambic,which I know supports the growth E. coli and Klebsiella pneumoniae in the early phases of fermentation, then the chances of it infected a non-spontaneously fermented beer is not worth worrying about. A lambic sits in the coolship, without oxygen introduced overnight, exposed to who knows what (E. coli and Klebsiella are known). After seeing the condition of some lambic breweries in beer hunter, I'd be more worried about organisms in lambics than Clostridium in no chilled wort.

James

 

[Ronin]

Its not all about botulism and oxygen.

If i had an unlimited amount of water to play with i would probably chill too but its Australia and here in VIC we are ina SERIOUS drought.

no ones died yet from no chilling.... and a few of brewers have lost a cube to infection via air getting sucked in....i'll take my chances and keep no chilling and leave some water for my kids to hopefully drink unless all our catchments get filled pronto.

I can't agree more.

I'd love to get a plate chiller, but I simply can't justify the use of water to cool my beer when we are on stage 4 water restrictions (Geelong) and the beer is perfectly fine being no chilled.

More people should consider this when using chillers IMO.

James

 

[buttersd70]

To quote an expert on botulism; the man himself, the Grim Reaper:

Shut up! Shut up you American. You always talk, you Americans, you talk and you talk and say 'Let me tell you something' and 'I just wanna say this', Well you're dead now, so shut up.

:lol: