Interesting!
They offered me the cans at 70% off and said if I had any issues with any of them they would reimburse me. At $1.80 a can, I’m not sure that it’s worth bothering them about it.
I was told that a constant problem with treacle deliveries is that the can lids do leak. Brand new batches come out of the box sticky and she has to wash them before putting them on the shelves. Don’t be surprised if your can has some treacle that leaked out, it’s not necessarily a sign that it has started fermenting. I bought an extra can in case anyone has issues with theirs. Just be sure to open it up when you get it so I have enough time to get a new can to you.
I updated the price in the group buy sheet.
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Hi, my only concern about those treacle cans would be low risk of botulism spores if they are way past the expiry date. A quick review of the scientific literature was reassuring for me, but personnally, discounts on foods is not worth the risk of food poisoning (spores are heat resistant).
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They expired in July.
And like I said the date is not there to say that the food inside is expired, it’s to warn you that the lid might come flying off. That’s why it says “dispose of on expiry” and not “best before”. The last FAQ on the Lyle’s site says:
Lyle’s Golden Syrup has a best before end (BBE) date - does it go off?
It is recommended all Lyle’s products be consumed within three months of opening. Over time pressure can build up in the tin in the space between the syrup and the lid, therefore it is not advisable to use these products if they are past their best before date. FAQs | Lyle's Golden Syrup
Je comprends ta crainte. La situation est exactement la même qu’avec du miel non-pasteurisé. Cependant, nous ne consommerons pas le treacle directement. Et bien que ces spores peuvent survivre l’étape d’ébullition du moût, les bactéries qui en émergent ne pourront survivre dans un milieu acide telle que la bière.
C. botulinum will not grow in acidic conditions (pH less than 4.6), and therefore the toxin will not be formed in acidic foods (however, a low pH will not degrade any pre-formed toxin). Combinations of low storage temperature and salt contents and/or pH are also used to prevent the growth of the bacteria or the formation of the toxin.
Et au niveau des neurotoxines produites par C. botulinum en anaérobie, ces neurotoxines sont sensibles à la chaleur et un traitement de chaleur dénaturera celle-ci.
Though spores of C. botulinum are heat-resistant, the toxin produced by bacteria growing out of the spores under anaerobic conditions is destroyed by boiling (for example, at internal temperature greater than 85 °C for 5 minutes or longer).
Référence: WHO
Salut, comme je suis microbiologiste de profession, tu peux comprendre mes réserves par rapport à la situation. On ne parle pas vraiment de milieu acide plus bas que 2 disons comme dans une solution vinaigrée. Les spores de botulisme sont extrêmement résistants aux intempéries de la vie, et n’en faut pas beaucoup pour causer un problème de santé (je ne suis pas un fanatique de miel non pasteurisé non plus…Pasteur n’est pas aussi connu pour rien!). Perso, je ne veux juste pas me compliquer la vie avec un produit ‘périmé’, bien que je n’ai jamais travaillé avec le treacle. Comme le dicton le dit, better safe than sorry!
Je vous mets aussi le document du USDA concernant le cannage d’aliments (par le site du CDC américain)
chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://nchfp.uga.edu/publications/usda/GUIDE01_HomeCan_rev0715.pdf
Vous pourrez constater dans le guide qu’un produit comme une bière avec PH disons 4.2, n’est pas un aliment considéré très acide. De plus,
Botulinum spores are very hard to destroy at boiling-water temperatures; the higher the canner temperature, the more easily they are destroyed. Therefore, all low-acid foods should be sterilized at temperatures of 240° to 250°F, attainable with pressure canners operated at 10 to 15 PSIG. PSIG means pounds per square inch of pressure as measured by gauge. The more familiar “PSI” designation is used hereafter in this publication. At temperatures of 240° to 250°F, the time needed to destroy bacteria in low-acid canned food ranges from 20 to 100 minutes. The exact time depends on the kind of food being canned, the way it is packed into jars, and the size of jars. The time needed to safely process low-acid foods in a boiling-water canner ranges from 7 to 11 hours; the time needed to process acid foods in boiling water varies from 5 to 85 minutes.
Disons que ca complique pas mal la brasse de s’assurer d’un boil assez long pour neutraliser le moût, s’assurer que la bière finale a pH < 4.2, etc…
Je voulais juste vous soumettre ces questionnements et observations.
Je ne veux pas en faire un débat d’experts (j’ai étudié en sciences et chimie des aliments), et tu as tout à fait le droit d’y aller better safe than sorry. Ce que je dis, c’est que la principale source de problèmes dans les cas de botulisme vient de la production de neurotoxines par la bactérie dans le produit (le treacle dans notre cas). Puisqu’un traitement thermique dénaturera les toxines potentiellement présentes, je ne vois pas il est où le danger.
Quant au problème provenant de la résistance à la chaleur des spores, comme tu l’écris, bien sûr que les low-acid foods devraient être stérilisés dans un autoclave. Mais on parle ici de bière qui est plutôt un high-acid food (pH < 4.6 selon la définition dans ta référence). Le pH d’un moût de bière descend rapidement au début de la fermentation, lorsqu’il y a encore de l’oxygène dissout. Lorsque le milieu devient anaérobique, les conditions ne sont plus propices à la croissance de bactéries produisant les toxines causant le botulisme.
Là où je serais plus prudent serait dans une situation de fermentation spontanée (dans un coolship par exemple) ou si le moût oxygéné n’est pas refroidi rapidement suivant l’ébullition (méthode no chill). Dans ces cas, il est important de diminuer le pH du moût à la fin de l’ébullition pour prévenir la croissance de bactéries pathogènes (et pas juste C. botulinum d’ailleurs).
Bryan Heit donne aussi d’excellentes explications dans son blogue au sujet des risques de botulisme dans la bière.
Bref, personnellement, je ne m’en ferai pas.
Salut, en effet n’en faisons pas un débat d’expert (c’est super comme formation en chimie des aliments!), mais comme médecin j’ai juste un certain malaise avec l’utilisation du treacle dans ces circonstances (je suis disons biaisé de voir des infections très sévères comme microbiologiste, j’en conviens…mais je me verrais mal être associé à une éclosion de botulisme 
). Si le groupe préfère poursuivre et utiliser ces produits pour ce Barrel fill, je préfère me retirer de cette brasse pour cette fois-ci. L’autre alternative serait d’utiliser en remplacement la bonne vieille black strap molasse non-périmée (je sais que ce serait moins dans le style parcontre), mais le treacle non-périmé n’est pas si dispendieux.
Désolé pour les désagréments que peuvent amener mon opinion sur le sujet
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Pas de problème. C’est sain d’en discuter ouvertement.
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Je n’ai aucun problème à payer le plein prix pour que tout le monde puisse participer!
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This discussion is interesting but I’m a bit confused. Aren’t botulism spores everywhere, and therefore the treacle is no different from the malt and hops people normally add to beer? Or is the concern that there could be botulism toxin in the expired treacle that somehow manages to survive the boil?
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Hi Marc, Clostridium botulinum is quite a great bug and it’s lifecycle and physiology is quite complicated (fascinating subject). Here is part of an article written on Uptodate (used by physicians for a plethora of medical subjects).
MICROBIOLOGY AND PATHOGENESIS
●The causative organism – C. botulinum is a gram-positive, rod-shaped, spore-forming, obligate anaerobic bacterium. It is ubiquitous and easily isolated from the surfaces of vegetables, fruits, and seafood, and exists in soil and marine sediment worldwide [2]. C. botulinum is divided into four distinct phenotypic groups (I to IV); it is more commonly classified into seven serotypes (A to G) based on the antigenicity of toxin production. A single strain usually produces only one toxin, but some strains may produce multiple toxins [3]. Clostridium butyricum and Clostridium baratii are two other distinct Clostridia species that are known to have produced botulinum toxin (types E and F) [4].
C. botulinum spores are heat resistant and can survive 100°C at one atmosphere for five or more hours. However, spores can be destroyed by heating to 120°C for five minutes [5]. When appropriate environmental conditions are present, the spores will germinate and grow into toxin-producing bacilli. These environmental parameters include:
•Restricted oxygen exposure (either an anaerobic or semi-anaerobic environment).
•pH near 7.0 or greater. Growth is inhibited when the pH is <4.6; however, a low pH will not degrade existing toxin.
•A temperature of 25 to 37°C. Some strains may grow in temperatures as low as 4°C.
Contamination of food cannot reliably be suspected on the basis of appearance, odor, or taste. Some strains (A and B) produce proteolytic enzymes that denature and “spoil” food, producing an unpleasant appearance, taste, or smell. However, other strains do not have this effect.
●Botulinum toxin – Eight distinct C. botulinum toxin types have been described: A through H. Of these eight, types A, B, E, and rarely F, G, and H, cause human disease; C and D cause disease in animals such as cattle, ducks, and chickens. C. botulinum toxin type H was first reported in 2014 and was the first new botulinum toxin type to be recognized in over four decades [6,7]. In contrast with the spores, the toxin is a heat-labile polypeptide readily denatured by heating above 80°C. The polypeptide toxin is composed of a light and heavy chain with a combined molecular weight of 150 to 165 kDa.
Botulinum toxin is released as a single precursor polypeptide chain that is then cleaved by bacterial proteases into a fully active neurotoxin composed of a 50-kDa light chain and a 100-kDa heavy chain [8]. Although the precise molecular mechanism of botulinum neurotoxin action is not fully understood, evidence supports a multistep process that includes binding of the neurotoxin to specific receptors at the presynaptic nerve terminal, toxin internalization into the nerve cell with translocation across the endosomal membrane, and intracellular endopeptidase cleavage of proteins necessary for neurotransmitter release.
Botulinum toxin can affect both excitatory and inhibitory synapses but is more active in excitatory neurons. It inhibits the release of multiple compounds, including dopamine, serotonin, somatostatin, noradrenaline, and gamma aminobutyric acid. Because of its large size, the toxin is thought unlikely to be able to pass through the blood-brain barrier; however, evidence is mounting that it could reach the central nervous system through either systemic spread or axonal retrograde or anterograde transport.
Botulinum toxin is the most potent bacterial toxin and perhaps the most potent known poison. The minimum lethal dose in experimental mice of botulinum toxin is 0.0003 mcg/kg. By comparison, the MLDs for curare and sodium cyanide are 500 and 10,000 mcg/kg, respectively [9]. It is estimated that 1 gram of aerosolized botulism toxin could kill at least 1.5 million people [10].
The toxin itself has no smell or taste. If ingested, the toxin is primarily absorbed by the stomach and small intestine, although the large intestine can absorb the toxin as well. The toxin is resistant to degradation by gastric acidity and human alimentary enzymes. However, botulinum toxin is inactivated in chlorinated water after only 20 minutes of exposure and in fresh water after three to six days [11]
As you can see, it is a complicated subject and there are quite a few situations where we have to be careful about it when home-cooking/brewing.
Thanks for that info but it doesn’t answer my question.
It does answer the second part of your statement (already formed spores from anaerobic conditions in the treacle can, that would survive the boil…)
Those spores that survived the boil can then lead to the Clostridium bacterium to propagate in the beer during fermentation (perfect temp at 20C or so…), secreting the toxin, and so on…
But botulism spores are “ubiquitous and easily isolated from the surfaces of vegetables, fruits, [etc]”. How are the spores in the treacle different from the spores on the malt or hops?
I would say, it is the possible bacterial/spore/toxin concentrations that will be different between both situations. In a spoiled can (I’m not saying our cans are spoiled, it’s an example), it creates a perfect anaerobic environment for Clostridium proliferation, spore formation and toxin production. In nature, environmental conditions are extremely not favorable for clostridial proliferation and spore formation on hops and malt. Clostridium is also mostly present in soil as well, not so much on grain and plants. In those conditions, it would be very surprising to find spore quantities (I don’t have data on that) as high as in a spoiled can. So I’m not so worried about Clostridium spore to get into my beers from malt and/or hops. Using a spoiled product in a beer is another story in my opinion (again, I’m not insinuating that the treacle cans are spoiled whatsoever)
Ok so because “the toxin is a heat-labile polypeptide readily denatured by heating above 80°C” then you are concerned about the quantity of spores that could be present in the can, is that right? According to the CDC “For almost all children and adults who are healthy, ingesting botulism spores is not dangerous and will not cause botulism (it’s the toxin that is dangerous). For reasons we do not understand, some infants get botulism when the spores get into their digestive tracts, grow, and produce the toxin.” (link)
To be clear: I am not trying to convince you to consume something you are not comfortable consuming! I’m just interested in what is true, and I also recognize that the CDC is not perfect, I’m open to other sources.
(Sorry if this is boring for most people). I forgot what you had said earlier about spores making it into the fermenter and creating the toxin there. So the idea is that there could be an unusually large quantity of spores in the can, spores are not killed by a standard boil, and then the spores create the toxin in post-boil environment. I think that Norm addressed the post-boil science well, but there’s also the fact that the treacle is 60% sugar which is not a very hospitable environment for Botulism, and I’ve written to Lyle’s to confirm whether or not the product is actually “canned” and highly anaerobic but I suspect it is not based on Kurt’s description of the leaking issue.