*image from Amazon

Mylar food storage bags are an important component of any food storage system.

So what is a Mylar Bag?
Mylar bags are made of a polyester film laminated to aluminum foil. Food grade metalized mylar bags are used for lining food storage pails. The advantage of storing bulk food in Mylar Bags is that instead of having to open a 50 pound bag of rice, wheat, beans or whatever, you’re able to open a more manageable and usable amounts.

How do they keep food fresh?
I think all plastics breath or let pass a small amount oxygen but Mylar bags cut this air transfer down to very very little I mean almost nothing measurable without scientific equipment. Usually used for food storage are 4 mil thick bags which are light, air, and water proof.
These bags are strong enough to hold vacuum if you use oxygen absorbers. This is because as the oxygen absorbers absorb the oxygen in the container, as well as what little passes through creating a vacuum .

How Can you store them once filled?
Mylar bags are not very puncture resistant or rodent proof so you have to use containers like a 5 gal pail to keep them in for protection and support.

How do you create a seal to keep food in and air out?
You can seal them closed with an Iron but you want to get the temperature of the iron set right so after the bag is ironed closed you can’t pull the bag open. I suggest cutting 1 bag into strips for you to do some trial and error until getting it right because with the iron too hot you will melt the bag instead of seal it. To seal the bag shut, place a smooth item like a board across the opening of the bucket, lay the bag across it, and iron the bag shut. Once you have it sealed you can either stick a label on the outside to identify whats in it or just take a black marker and write on it.
I’ll post a video shortly.