Most of the information below comes from PrimalSurvivor.com. There are hundreds of reputable preppier sites out there to do your own research. This just happens to be a site I’ve used several times.

First, about mylar bags

“Mylar bags are made from a metal-like material which is impervious to moisture and oxygen.  By sealing flour in Mylar bags with oxygen absorbers, the flour is completely safe from light, moisture and oxygen.  Even insect eggs can’t hatch because there isn’t oxygen in the packaging.

“When stored this way, white flour can last 10-15 years.  Whole-wheat flour can last approximately 10 years this way.” – PrimalSurvivor.com

At first this all seems overwhelming. I felt that way when I first considered storing dried foods in mylar bags. I read advice from a variety of sites and soon realized it’s not that complicated. You do need to familiarize yourself with the needed items and process.

• Choose your size of mylar bag – I use ones with a zipper but still heat seal them.
• Know the size of oxygen absorbers needed for your food item (There are charts out there for you to use, but I usually use two 300cc packs for each one gallon bag and one 300cc pack for a quart. Please do the research. I’m by no means an expert.) I found a chart here.
• Seal the bag with a heat source. I use a cheap flat iron, one used for straightening hair.

I have used the following items with no problems:

50 one gallon bags
100 quart bags
100 Oxygen absorbers (10 packs of 10 is what you need, or you have to pack 100 bags at a time.)