Preparedness blog

What is the Shelf-Life of an Open Can?

By Marc from Ready Store
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One of the most common questions that we're are asked is "What is the shelf life of a #10 can once it is opened?"

General tips
With all kinds of food, the shelf-life will be decreased by three things:

1. How long it has been opened
2. How much it is exposed to oxygen and moisture
3. How much heat the food has been exposed to

The higher temperature that a food is stored at, the faster it looses nutrients and taste. Oxygen and moisture will also lower the shelf-life of a food item.

Try and store your food after opening in a cool, dark place and preferably in an airtight container. Usually, the plastic lid that comes with a #10 can will be sufficient.

Freeze-dried food
Most people know that freeze-dried food has a 25 - 30 year shelf-life but does that change after it's opened? The quick and easy answer is yes, the shelf-life does change once you open the can.

open can shelf life freeze dried foodThe in-depth answer depends on how the freeze-dried food is prepared. The freeze-drying process slowly lowers the temperature and pressure in a chamber and removes the oxygen and water from the food. Once the oxygen and moisture are extracted, it allows the food to have an extended shelf-life free of spoilage. Add oxygen absorbers on top of that and you have a can of food with a long shelf-life of 25 - 30 years.

Once you open your can of freeze-dried food, it is automatically exposed to two things - oxygen and moisture in the air. That's why it's important to use the plastic lid and lock out the moisture as much as possible from an open can of food.

You'll be able to open the can and eat the contents for 6 to 12 months. When you open the can of freeze-dried food, you won't have to refrigerate it either. It won't spoil that quickly. However, if you do prepare a dish with water, you should treat that food like any other perishable item and refrigerate it.

If you're wondering if your freeze-dried food has gone bad look for signs of exposure. If the food is chewy and gummy, usually that's a sign of overexposure.

Dehydrated food
Dehydrated food is prepared in a similar way to freeze-dried. However, the moisture is taken out more quickly which doesn't allow for easy rehydration.

Dehydrated food, if stored correctly, can last for 3-12 months in an open can.

Dried food
Items like dried grains, beans, rices, etc. will last for years in an open can. As long as you keep them covered and stored correctly, they won't spoil very fast.

14 years ago
NameDave T
9 years ago at 11:27 AM
We've got a years supply for 2 of dehydrated #10 cans from Sam Andy & Perma-Pak that is over 35 years old.It has been stored in a lower level room that was built to use as a food storage pantry, with lower heat levels in all seasons.Is any of this still good, i.e. nutritious and useable? If not any good except for the sugar and salt, what can we do with it? Would Feed lots or farmers be able to use it to feed hogs or cattle? Thanks for taking the time to answer this question.
8 years ago at 2:52 PM
If you put the opened contents in a mylar bag with an oxygen obsorber and seal it will it be good for longer and about how much longer?
8 years ago at 3:31 PM
For a smaller family/group of 2 or 3, wouldn't it be better to seal your food items in smaller mylar bags and THEN seal them into the #10 containers? That way, folks like us (smaller groups), could enjoy a greater variety of foods and menu changes, without having to worry about spoilage of the remaining contents of the #10 can. Also, it could help to insure against insects and pests contaminating the entire remaining amount of food left in the container if the lid was not properly replaced. Dry goods, (oatmeal, cereals, grits, beans and especially flowers and cornmeal), seem to be the most suseptable to insects, moisture and oxygen. The chances of loosing the bulk of a larger storage container of these food items, including freeze dried and dehydrated items, could be remedied if individual smaller packaging (mylar?), within a #10 container, was available from the supplier and environmentally sealed before selling to the buyers. Your thoughts (and any other thoughts and comments from others) about this would be appreciated.