Mylar Bags do not ‘breath’ where as even vacuum saver bags eventually allow oxygen in. I neither vacuum or purge with CO2 my Mylar bags I simply pack them as tight as I can then squeeze as much air and throw in oxygen absorbers to take out the remainder of the oxygen in the bag. What's left is just inert gases basically the nitrogen and CO2 gasses that are often used when sealing long term food. As I said all #10 cans I have purchase come with a plastic lid to reseal the can and infact most sellers of these cans offer extra lids for sell.
Mylar Bags do not ‘breath’ where as even vacuum saver bags eventually allow oxygen in. I've read that but haven't found it to be a problem. I rotate out beans/rice/cornmeal/peas/instant potatoes/powdered milk/etc. What I use for cooking now, I vacuum packed 2-3 years ago. They're still holding their vacuum and I haven't noticed the slightest decrease in freshness, quality, cooking length or taste. I hope to build up to a five year supply/rotation.
These items (cornmeal, black-eye peas, elbow macaroni) below were vacuum packed in august of '09 and are still holding the same vacuum as when packed.
