The airtight, light-blocking barrier that does the real preservation work in long-term dry storage. Sealed with an oxygen absorber and tucked inside a bucket, mylar is what turns a five year staple into a twenty-five year one.
- Thickness matters. Five mil is the practical minimum for food storage, and seven mil or thicker resists the punctures that rice edges and rough handling cause.
- Buy heat-seal bags, not zip-top. Resealable mylar does not hold a true airtight seal, which defeats the entire point of using mylar at all.
- Look for a true foil layer. Clear or lightly metallized bags pass oxygen slowly over years.
- Size to your working supply. Several one gallon bags inside a five gallon bucket beat one five gallon bag, because opening the big one exposes everything at once.
- Remember that mylar alone is chewable. Rodents go through it without slowing down, which is why it belongs inside a bucket rather than sitting on a shelf.
