Recently I've seen uncooked, prewrapped-in-foil potatoes at the store, meant for baking. But I've always read that keeping potatoes wrapped tightly in foil at room temperature is one of the ways that botulism can occur. Is this a safe product? Is it only after cooking that botulism can grow?
From what I understand about this, it's not so much about the raw potatoes being foil wrapped as it is about the baking and storing afterward.
Though rare, most foodborne botulism in the U.S. is from improper home canning. But according to a report from the Centers for Disease Control and Prevention, potatoes baked in aluminum foil and left at room temperature can also cause botulism. Here's why.
As a common soil-dwelling organism, C. botulinum can easily contaminate potatoes or any other crop that comes in direct contact with soil. Thorough cooking usually kills the organism's spores, the source of the deadly toxin. But a foil-wrapped potato holds in moisture, sometimes preventing its surface from reaching a high enough temperature to kill spores. Paradoxically, the heat kills off competing bacteria, making it easier for C. botulinum to grow. Moreover, at room temperature, foil-wrapped potatoes provide the oxygen-free environment needed for toxins to form.
Advice? If you bake potatoes in foil, do not leave them out for any significant period of time, even unwrapped. As with any food, eat it soon after cooking or refrigerate it promptly. The Journal of Infectious Diseases, July 1998.
Many others sources also recommend that, after baking, potatoes should be immediately removed from the foil and not allowed to remain in the danger zone. Translate that to unwrap and serve or refrigerate right away.
One downside I can think of to the pre-wrapped potatoes would be if they are not kept at proper storage temperatures, moisture/condensate could accumulate inside the foil. And you can't see inside the foil to determine the overall appearance and quality of the potato.
One of the nicer things about botulism (there are not many) is that heat does neutralize the toxin. So unless you are licking the raw potatoes, not likely to be a problem.
The odds of the foil-wrapping being actually airtight are also about zero, so it's unlikely that you'd actually get botulism, as that requires an anaerobic environment.
Now, why you'd buy foil-wrapped potatoes in the first place is beyond me, but I'm not seeing a safety issue here.