Throw Out Your Cubes

[black_labb]

Should be able to work it out with info provided here

http://en.wikipedia.org/wiki/Water_activity

going by the wikipedia based info Clostridium botulinum is inhibited from 0.97, not the 0.93 RobW stated. Where did you get that figure from RobW? was it a typo or was it some other (possibly better) source. It didn't have a SW rating for wort but fruit juice is 0.97. If my memory is correct fruit juices have around 8-20% sugar. wort is usually atleast 10% sugar I'd assume. Not sure how to use the formula but with some more research I'm sure it wouldn't be too hard.

It sounds like the Combination of hops, acidity, sugary solution (related to the water activity), presence of some oxygen and heat should work together to keep things under control even if you chuck a bit of dirt into your mash for some earthy flavours.


edit: beatn'

 

[bradsbrew]

@ Darren are you able to, within your work environment, get the CB to grow, or test levels if introduced, in a cube that is filled with hot wort in a simulated Hbrewer environment? If so that would be a great experiment.

Please forgive my stupidness if this is not possible. I am a construction training manager not a scientist. This thread has turned into a good read.


Cheers

 

[donburke]

@ Darren are you able to, within your work environment, get the CB to grow, or test levels if introduced, in a cube that is filled with hot wort in a simulated Hbrewer environment? If so that would be a great experiment.

Please forgive my stupidness if this is not possible. I am a construction training manager not a scientist. This thread has turned into a good read.


Cheers

bags not being in the case swap

 

[kieran]

http://www.vitis-vea.de/admin/volltext/e045205.pdf

Yeasts were more resistant than bacteria. Most yeasts grow at Aw between 0.96 and 0.88.

.. yeah, so if yeast won't ferment below 0.88, then we know that a ready-to-brew wort must be a minimum of 0.88.

 

[kieran]

not the 0.93 RobW stated. Where did you get that figure from RobW?

The article says 0.93 right here.

 

[Feldon]

My understanding is that the single-celled organism Clostridium botulinum that causes botulism poisoning is itself harmless. It is the toxic chemical this bug produces that is dangerous (have seen it described as "the most lethal toxin known to man"). The toxin is a waste product that is produced by Clostridium botulinum during its normal functioning in oxygen-deprived (anaerobic) environments - much like a yeast cell happily produces CO2 and alcohol as waste product in the normal coursse of its life.

According to a referenced article in Wikipedia, Clostridium botulinum is commonly found about the home. If ingested by a non-infant the acidic conditions of the gut prevent the bug from functioning - so no toxins are produced. However, kids under 1 year old have not yet developed their full digestive juices so they can die if they ingest the bug).

The botulism toxin is destroyed above 60 degrees C, but the spores of Clostridium botulinum can survive boiling, and if they do and they later arive in conditions (such as temp. pH, etc.) that are favorable, they can start growing and reproducing and in doing so will produce more of the toxin as a waste product.

I thought this picture might help show where in the brewing proccess the likilhood of botulism contamination would occur in the No Chill method (if it is likely at all). Remember the wort might be free of Clostridium botulinum and its spores coming out of the wort boil, but if spores exists in a dirty cube container they might survive (?) to grow and reproduce as the wort slowly cools to morre ideal temperatures).



(Pic sourced from G. Menz. P. Aldred, & F. Vrieskroop, 'Pathogens in Beer', in V.R. Preedy (ed.), Beer in Health and Disease Prevention, Academic Press (London, 2009), p.407 - the coloured graphical additions are mine. Book is available by online by searching Google Books).

 

[Batz]

OK worst case scenario, clostridium botulinum does take a hold in my cube.

Now will the cube swell up like other infections? and how long that would take?

Thanks to all the informed for the positive posts.

Batz

 

[kieran]

I'd like to see the same pic, but drawn for Endospores. They just jump over all those hurdles like Steve Hooker.

 

[Feldon]

@ Darren are you able to, within your work environment, get the CB to grow, or test levels if introduced, in a cube that is filled with hot wort in a simulated Hbrewer environment? If so that would be a great experiment.

Good idea but need to be careful. Some authorities might look on cultivating lethal toxins outside of approved programs as something linked to bio-terrorism .

 

[Thirsty Boy]

I'd like to see the same pic, but drawn for Endospores. They just jump over all those hurdles like Steve Hooker.

yep, but endospores dont produce any toxin - they have to germinate and grow first. Thats when the hurdles count.

 

[kieran]

Now will the cube swell up like other infections? and how long that would take?

The nail on the head question.... it is actually killed by CO2, so it isn't producing that. Cant

... BUT it does this to pasterised milk seeded with Clostridium botulinum:
Milk stored at 21 degrees C curdled and exhibited a yogurt-like odor at 2 days and was putrid at 4 days.

 

[kieran]

yep, but endospores dont produce any toxin - they have to germinate and grow first. Thats when the hurdles count.

Not sure if you've missed it. Germination will not happen unless there's an anaerobic environment that's sensed by the spore (the bacterium with a capsule around it). Now if the spore isn't killed by boiling, by sanitisation, by pH, by those hurdles... and that spore ends up in your oxygen-deprived, non-fermenting NC wort. Then the Go switch flicks on, and its off to infectionland we go, and toxins are produced. 500g of which can kill half the human population.
Anyway, from the discussion here, it seems that Aw and maybe Hops are the two things that might have a nullifying effect in a NC "anaerobic" environment, they're in the NC wort, and perhaps the only things that'd stop said spore going postal.

 

[Nick JD]

Good idea but need to be careful. Some authorities might look on cultivating lethal toxins outside of approved programs as something linked to bio-terrorism .

Nicole Kidman's forehead is a bioterrorism zone? People get botulinum toxin injected into their face.

 

[stux]

going by the wikipedia based info Clostridium botulinum is inhibited from 0.97, not the 0.93 RobW stated. Where did you get that figure from RobW? was it a typo or was it some other (possibly better) source. It didn't have a SW rating for wort but fruit juice is 0.97. If my memory is correct fruit juices have around 8-20% sugar. wort is usually atleast 10% sugar I'd assume. Not sure how to use the formula but with some more research I'm sure it wouldn't be too hard.

It sounds like the Combination of hops, acidity, sugary solution (related to the water activity), presence of some oxygen and heat should work together to keep things under control even if you chuck a bit of dirt into your mash for some earthy flavours.


edit: beatn'

My hydrometer says that Apple Juice was about 1.060 iirc


according to the wiki article,

Juice 0.97

Wort would certainly be around there... unless its a barley wine!

 

[Feldon]

Nicole Kidman's forehead is a bioterrorism zone? People get botulinum toxin injected into their face.

Using the toxin is a completely different thing to producing it.

 

[the_new_darren]

@ Darren are you able to, within your work environment, get the CB to grow, or test levels if introduced, in a cube that is filled with hot wort in a simulated Hbrewer environment? If so that would be a great experiment.

Please forgive my stupidness if this is not possible. I am a construction training manager not a scientist. This thread has turned into a good read.


Cheers

Bradsbrew,

Just need to find some time and jump all the ethical hoops but you read my dreams (well thoughts before sleep).

I just need to check the containment requirements (anyone have the microbiological standards on hand?? PC1, PC2?

d

 

[Nick JD]

Using the toxin is a completely different thing to producing it.

So detonating a dirty bomb is okay, but refining uranium isn't?

 

[Feldon]

So detonating a dirty bomb is okay, but refining uranium isn't?

You're right you know. Must be heaps of labs around the world growing the botulism bug for use in cosmetic applications. Who are they? And what controls are there?

Sorry everyone, but this is :icon_offtopic:

 

[Nick JD]

You're right you know. Must be heaps of labs around the world growing the botulism bug for use in cosmetic applications. Who are they? And what controls are there?

Sorry everyone, but this is :icon_offtopic:

Not really off topic. I'm really interested to see if anyone can culture up some botulinum toxin in wort.

Can't see it being a big issue. And if it is - Darren won't be posting anymore unless they have internet access in Guantanamo.

 

[kieran]

I just need to check the containment requirements (anyone have the microbiological standards on hand?? PC1, PC2?

d

PC2 to be sure. You'll also need special approvals as it's a restricted Tier2 biosafety agent on the "Security Sensitive Biological Agents" list here.

Looks like the hoops you've got to jump through are pretty significant.. although your dept might be able to deal with any requirements if you've got existing licensed dealings for other bugs other groups are using.

Including a $101 fee for a background check to prove you're not a terrorist.

This amendement is to incorporate recently announced fee increases by AusChecks checking partners ASIO and CrimTrac.

Terrorists have a lot to answer for.. .. bastards.

http://www.microbiol.unimelb.edu.au/staff/...calegenetic.pdf {this is waaay old with references to the old GMAC, but still gives an idea for containment}