JesBelle wrote:
Isn't confit usually cooked though? As I understand it, the botulinum toxin is fairly delicate. It's the spore that thinks it's Rasputin.
Spores can exist pre-cooking, and can survive light cooking. Typically confit is cooked hot enough and long enough (6-12 hours in most traditional recipes I've seen) to do the trick, but that is IF you follow instructions, just like SV.
On the earlier question of oxygen:
...O’Mahony et al. (2004) found that the majority of pouches after vacuum packaging had high levels of residual oxygen, this doesn’t imply that the Clostridium species – which require the absence of oxygen to grow – aren’t a problem since the interior of the food often has an absence of oxygen. This is true for traditional cooking as well. In that vein, people are often confused because they think if they heat a food (eg. garlic in oil) up to a sufficient temperature, then they will kill pathogens. Of course, you can heat your garlic in oil to 150 C, but the interior of the garlic stays at 100 C until it dries out (unless pressure cooked), at which point you won't have much edible.
Modernist Cuisine also has a long and thoroughly researched section of food safety that generally concludes that SV is about as dangerous as most cooking, which is pretty rife with danger. Things cooked at high temperature (say >60) for long periods are probably safer. The biggest difference on the Internet is that SV has some well written, accessible, articles like Baldwin which discuss the dangers, but very little to discuss the dangers of salad (which is wildly dangerous), at least at the cook's level.