Boiled water & cooked food--how hot is hot enough?

Does anyone know for sure at what temperature Giardia, Cryptosporidium, and other water-borne nasties kick the bucket? I've always brought my water to a rolling boil before either using it or letting it cool down to drink, but is that really necessary? I can see a scenario where a person might have to conserve fuel, and if bringing it to, say, 200 degrees farenheit would serve as well, then I can see some advantages to not going all the way to full boil.

On a slightly different vein, suppose you are in a survival scenario and your food is spoiling/has spoiled. For example, all your cans of Spam and Del Monte green beans have bulges in them. Would cooking this food ever make it safe enough to eat? Are there common bacteria that can survive at 400 degrees for 6 hours and return to exact their revenge on you? (Palatibility is a subject for another day.)

Please note, I am well aware of the dictum "better safe than sorry." I would never dream of not coming to a full boil or eating spoiled food unless there was simply no other alternative than death by thirst or starvation. I'm just wondering if anyone knows the facts.

Regards, Vince

In general 180F will kill most non-spore forming bacteria. Most of the time, when an organism (bacteria or parasite) can form a cyst, boiling will be your only option. Even then there are heat resistant organisms that will survive boiling. Although, many or most of the pathogenic (disease causing) organisms, will be destroyed by boiling.

As to food that has spoiled, keep in mind that some bacterial toxins are heat stable and even if you heat the food, the toxins will still be present and can cause illness. That is why you should keep hot foods hot and cold foods cold, to prevent bacteria from growing in the first place. Some bacteria produce exotoxins, in that, while the organism is living, it will produce and eliminate these toxins, these toxins may or may not be heat stable. The other situation is where an organism will produce endotoxins, these are generally release when the organism dies, lyses (pops open) and releases these toxins. Again, they may be heat stable.

Cans that have bulges, would indicate the possible presence of anaerobic bacteria (bacteria that grow without oxygen being present), such as Clostridium botulinum. Food from these cans should not be consumed under any conditions, as you may develop botulism, a life threatening illness.

Pete

Here are the CDC links on food and water borne diseases:

Food Borne Diseases

Water Borne Diseases

Pete

That's exactly the information I was looking for. If I understand you correctly, then even though the bacteria in the food might be killed by the cooking, the toxins they had already produced will still be there and could be harmful.

I found it interesting that the link you provided does recommend boiling for one full minute, or three minutes at altitude.

Many thanks, Vince

Yes, it is possible for foods that have been cooked to contain heat stable toxins. If uncooked food were allowed to sit around for a period of time prior to cooking and the bacteria significantly multiplied producing heat stable endo or exotoxins you could still develop food poisoning.

Pete

norad,

Remember too that for every 1,000 ft. above 6,000 ft. the boiling point temperature raises 2 degrees. So you should keep that in mind if you are going to be cooking at higher altitudes.

If your going to take food into the wilds with you, I suggest that you take freeze dried or dehygrated and re-hydrate and cook it.

I carry cup of soups and the like while outdoors. I was asking about canned because that's what I keep in my home and truck. I hope to eventually have a years supply in my basement. Now I know what to do if I ever encounter the dreaded bulged can.

Regards, Vince

Twice, while grocery shopping, I have found bulging cans in the store. Both of them had dents on their sealing rims. I don't know if that had anything to do with it, but at today's prices, I inspect every every container I buy.

It's bad enough to be sick when everything is going smoothly, but under the stress of trying to survive, too... I'll pass if I can.

Sue

Also the bubbles will start forming on the bottom of the pan well below the boiling point, maybe around 170 degrees (at low altitude), so this is not a good indicator of "near boiling" temperature.