Rice and Beans. Franks and Beans. Beans and Beef. And spam!

That's just one of many. Search on "Food grade mylar bags" and you'll find lots of other sources. One that I like are the ziplock style 1 gallon bags. You fill, add your extras (Dessicant, O2 absorber, etc.) and then heat seal closed. Now in the future if you need to open it you can cut the top above the ziplock, use some and ziplock it back up between uses. You could also re heat seal it below the ziplock if you decide to use, say, half the contents but want to save the other half. I would never rely on the ziplock alone for long term however.