Shelf life of sealed food

Most freeze dried food in plastic and foil packs should be good for 2-4 years, but maybe not much longer.

I have some freeze dried food in a #10 metal can, and I purchased several in the summer of 1980. I might try them sometime, but I suspect they will be good (enough).

–B.G.–

I just checked some Packit meals and they say 1 year from the date on the packet, I would have no issues using them past the year though.

When sorting out my food for a trip last week I noticed I had two deserts which I had taken the extra bits and desiccant out of in order to save weight but they never got used, I put them to inside and will try them a home to see of they taste ok.

OK…here is my take. The items you have came out of a large can and were resealed. With FD food it is obvious it isn't good once you open it – it will be soft (it should be crisp) and if soft, that means it got moisture in it over time. I have had FD foods go bad in storage and they always were soft and smelled really off (sour, rancid, that kind of odor).

Meat? I am not so sure I'd keep it. Veggies more likely.

If they are air dried veggies and are hard with no off smell? You can eat those for year.

This is of course off the record advice ;-)

Well, Packit responded by saying that about 2 years is the limit for food stored in that fashion. I think I'll probably toss the chicken and maybe try the veggies.

My question is, then, What is the best way to store food for long periods of time? I recently bought a heat sealer and would like to pick up some mylar bags and oxygen absorbers. I read that this combo is even better than vacuum sealing. What I like about the heat sealing / O2 absorber method is that you can always reseal, add another O2 absorber if necessary, and you are good to go again.

Google "preppers" + food storage.

Pretty serious folks when it comes to "long term".

Want my 2 cents? Get a food vac and use the set up for mason jars:
http://gazingin.com/2013/05/07/how-my-garden-grows-preserving-seed-packets/
(That is my personal blog). I have both sizes and use it to seal everything I keep in my pantry – dried veggies, rice, pasta, fruit, etc. It works GREAT for long-term dry storage where canning isn't needed.

I work in food packaging research so can provide some input. I suspect it could either be OK or taste bad, but not kill you. If it tastes/smells bad, don't eat it. That being said…I disavow any responsibility.

– If the food stayed dried (and not exposed to the environment) it will not have problems with mold, yeast, or bacteria growth (see plot below). You can feel if the food is dry and crumbly.
– Sachets with ground iron particles are used along with the foil or metallized packaging to keep the oxygen low and prevent rancidity.
– If there are leaks in the package and the sachet has lost its effectiveness, the food could be rancid. That means that it will taste and smell like paint, but it won't kill you, so you can test that with your nose.
– The food could also change chemically, causing flavor or color changes, but you will also be able to detect that, and it won't harm you.

This (busy) plot shows how quickly the various reactions occur at different levels of water activity, which is the x-axis. High water activity is equivalent to high moisture content. Most cookies, crackers, cereals are between 0.1 and 0.4 water activity.

Hope that helps,
Tom