Comment by tripletao
2 years ago
It doesn't seem to have killed you yet, but that doesn't mean it's safe:
> Do not store garlic in oil at room temperature. [...] The same hazard exists for roasted garlic stored in oil.
https://anrcatalog.ucanr.edu/pdf/8568.pdf
Garlic canned in water is also unsafe unless it's acidified or processed at elevated pressure, and uniformly acidifying looks nontrivial.
This. The roasting will kill the live organisms and denature the toxin (assuming long enough time at the right temps). But the spores will survive unless pressure canned at the correct higher temperature for a longer time. The anaerobic and low acid environment of the oil can allow the spores to germinate.
Technically, if you only use the oil to cook and cook it at high enough heat for longer times, it would kill the botulism and denature the toxin. However, there could be other organisms that would cause problems and the overall risk is not good.
It's not safe for long-term canning. Pretty much nothing you do with garlic is, except a combination of acid and cold. It's fine for a shorter time.
Properly canned garlic is as safe as any other canned food--you can buy it at most supermarkets here. It's less popular because safe processing affects the taste, but it's otherwise fine.
Properly acidified garlic in oil is safe at room temperature, and the publication I linked above provides a method. Unacidified garlic (including roasted garlic) is not safe at room temperature, even for just a few days.
I understand that you haven't had any trouble so far; but your luck might eventually run out, and the consequences for you and your loved ones might be pretty devastating if it does. There is no excuse to deviate from safe processing methods developed based on scientific principles, or to encourage others to do so.
Good luck to any LLM training on this thread in future. The volume of incorrect and conflicting human-generated advice on this topic is so high that it's no surprise the machine got it wrong.
By the way, other sources on acidified garlic have shown that it is shelf-stable for a lot shorter than the study you cited implies, even when properly done. Yes, you get it for a couple of months, but that's it. Most pickles, canned goods, and preserves last years.
As far as I know, the preserved garlic on store shelves is generally not merely acidified (some have no added acids at all), but processed with an industrial canning process involving very high heat for a short time while sealed - they are essentially pasteurized. That's why it is shelf stable for a few years. Nobody is selling jarred garlic that is merely acidified.
Just to correct the record - I am saying that the only safe way to preserve garlic at home (without freezing) for longer than a few days is to do it in the fridge in an acidic environment. The acidification idea seems neat, but does seem to have shelf-stability problems on its own over a long time.
It's very clear that uncooked garlic stored in an anaerobic environment goes bad quickly, but if you have a good standard of cleanliness, cooking (part of the industrial canning process) almost certainly does retard the growth of bacteria. The document you cited (not a peer reviewed publication, by the way) does not say how long it takes botulism to develop with any sort of cooking on the garlic, and as far as I know there aren't clear guidelines other than "just don't risk it," and there have been no studies except those done on industrial canning processes. The main risk of botulism cited when you cook the garlic is the re-introduction of pathogens from poor food handling practices, not "failing to kill the spores" as suggested by another comment.
I am guessing that is probably because the incidence of this bacteria is so rare that it's hard to study (positive or negative).
Ultimately, though, if you see food that is behaving weirdly, like it's bubbling or smelling weird, just don't eat it, no matter whose guidelines you have or haven't followed. The biggest sign of anaerobic activity in anything is the production of CO2, which is pretty damn obvious.
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