In a world of increasing food prices, supply chain disruptions, and growing interest in self-sufficiency, long-term food storage has moved from the fringes into the mainstream. What was once the domain of doomsday preppers and military logistics is now practiced by suburban families, outdoor enthusiasts, emergency management agencies, and food brands selling bulk staples online.
At the heart of this movement is a material most consumers interact with daily without knowing its name: Mylar.
Mylar food storage bags have become the gold standard for long-term food preservation — and understanding why requires a quick dive into material science, food chemistry, and practical packaging design.
What Is Mylar, Exactly?
Mylar is a brand name (owned by DuPont) for BoPET — biaxially-oriented polyethylene terephthalate. In simpler terms, it’s a polyester film that’s been stretched in two directions during manufacturing, creating an extraordinarily strong, flexible, and barrier-resistant material.
Mylar was originally developed in the 1950s for industrial and aerospace applications. NASA uses it in spacecraft insulation. Emergency blankets (those shiny “space blankets”) are Mylar. Helium balloons are Mylar. And — most relevant to this discussion — some of the most effective food packaging on earth is Mylar.
Why Mylar Outperforms Other Food Storage Materials
To understand why mylar food storage bags are superior for long-term preservation, compare them against the alternatives:
| Property | Mylar Bags | Plastic Zip Bags | Vacuum Seal Bags | Glass Jars |
|---|---|---|---|---|
| Oxygen Barrier | Excellent | Poor | Moderate | Excellent |
| Moisture Barrier | Excellent | Moderate | Good | Excellent |
| Light Barrier | Excellent (opaque/metallic) | None | None | Partial |
| Puncture Resistance | High | Low | Moderate | N/A (rigid) |
| Weight | Very light | Light | Light | Heavy |
| Stackability | Excellent | Poor | Moderate | Poor |
| Cost Per Unit | Low | Very low | Moderate | High |
| Shelf Life Extension | 10–25+ years | 6–12 months | 1–3 years | 5–15 years |
| Space Efficiency | Excellent | Good | Good | Poor |
The numbers tell the story. For shelf life, barrier protection, and cost-effectiveness, mylar food storage bags outperform every alternative in long-term storage applications.
The Three Enemies of Stored Food
Food deteriorates through three primary mechanisms, and mylar food storage bags address all three:
1. Oxygen
Oxygen drives oxidation — the chemical process that causes fats to go rancid, vitamins to degrade, and flavors to deteriorate. Standard food-grade Mylar (typically 5–7 mil thickness) has an oxygen transmission rate (OTR) near zero when properly heat-sealed. Combined with oxygen absorber packets, Mylar bags can reduce oxygen levels inside the bag to below 0.01% — essentially creating an anaerobic environment.
2. Moisture
Moisture enables microbial growth (mold, bacteria, yeast) and accelerates chemical degradation. Mylar’s moisture vapor transmission rate (MVTR) is extremely low, keeping dry goods at their original moisture content for years. This is critical for storing items like grains, beans, rice, powdered milk, and dehydrated vegetables.
3. Light
UV and visible light degrade nutrients (particularly vitamins A, C, and riboflavin) and can cause off-flavors in fats and oils. The metallic (aluminized) layer in standard mylar food storage bags blocks virtually 100% of light — an advantage that clear plastic and vacuum bags can’t match.
What Foods Are Best Stored in Mylar Bags?
Mylar food storage bags are ideal for dry, low-fat, low-moisture foods:
- ✅ White rice (25+ year shelf life in Mylar with O2 absorbers)
- ✅ Hard wheat and other whole grains
- ✅ Dried beans, lentils, and legumes
- ✅ Rolled oats and steel-cut oats
- ✅ Pasta (dry)
- ✅ Powdered milk and whey protein
- ✅ Freeze-dried fruits and vegetables
- ✅ Dehydrated meals
- ✅ Sugar, salt, and baking staples
- ✅ Coffee (whole bean and ground)
- ✅ Tea leaves
- ✅ Spices and dried herbs
- ✅ Flour (with proper O2 absorption)
- ✅ Cornmeal and corn starch
- ✅ Emergency food rations
Foods NOT recommended for Mylar storage:
- ❌ High-fat items (nuts, nut butters) — fats go rancid even without oxygen over very long periods
- ❌ Fresh or wet foods — moisture trapped inside creates dangerous bacterial conditions
- ❌ Brown rice — higher oil content limits shelf life even in Mylar
- ❌ Any food with moisture content above 10%
Mylar Bag Specifications That Matter
Not all mylar food storage bags are created equal. Key specifications to evaluate:
Thickness (Mil)
- 3.5 mil — Light duty, suitable for shorter-term storage (1–3 years) or secondary packaging
- 5 mil — Standard food storage thickness, appropriate for most long-term applications
- 7 mil — Heavy duty, maximum puncture resistance, ideal for rough handling or sharp-edged foods (pasta, sugar crystals)
- 7.5+ mil — Industrial grade, used by commercial food packagers and military suppliers
Metallization
Standard food-grade Mylar bags feature an aluminum or aluminized layer bonded between polyester films. This metallic layer is what provides the light and oxygen barrier. Some bags use actual aluminum foil laminate (higher barrier) while others use vacuum-deposited aluminum (thinner, slightly lower barrier but more flexible).
Heat-Seal Compatibility
Mylar bags must be heat-sealable to create an airtight closure. The inner layer (typically polyethylene) melts and bonds when compressed between heated jaws. Proper seal temperature varies by bag thickness — usually 300–400°F with 2–5 seconds of dwell time.
Food-Safe Certification
All mylar food storage bags intended for direct food contact should be FDA-compliant and free from BPA, phthalates, and other harmful chemicals. Reputable suppliers provide material safety data sheets (MSDS) and food-contact certifications upon request.
How to Properly Pack Mylar Food Storage Bags
The bag itself is only half the equation. Proper packing technique determines actual shelf life:
- Choose the right bag size for the quantity of food (minimize headspace)
- Fill the bag, leaving 2–3 inches at the top for sealing
- Insert an oxygen absorber of appropriate capacity (typically 300cc per gallon of food volume)
- Squeeze out excess air gently
- Heat-seal the opening using a flat iron, impulse sealer, or clamshell heat sealer
- Label the bag with contents, date, and quantity
- Store in a cool, dark, temperature-stable location (ideal: 60–70°F)
- Optionally store sealed Mylar bags inside 5-gallon food-grade buckets for additional protection against rodents and crushing
The Growing Commercial Market for Mylar Food Bags
Beyond individual preppers and homesteaders, the commercial market for mylar food storage bags is expanding rapidly:
- Emergency preparedness companies selling pre-packed food kits
- Freeze-dried food brands (both DTC and retail)
- Pet food and treat manufacturers seeking extended shelf life
- Coffee roasters packaging whole bean and ground coffee
- Supplement and superfood brands packaging powders and dried products
- Meal kit companies packaging dry components
- Food banks and humanitarian organizations assembling long-term food supplies
Source Your Mylar Food Storage Bags from a Trusted Partner
Whether you’re a food brand packaging products for retail, an emergency preparedness company building survival kits, or a commercial operation requiring bulk food-grade Mylar bags, quality and consistency are non-negotiable. Custom Product Packaging supplies premium mylar food storage bags in a full range of sizes, thicknesses, and configurations — from stand-up pouches with resealable zippers to flat bags for heat-seal closure. All bags are FDA-compliant, food-grade certified, and manufactured with consistent barrier properties you can trust. Custom printing, private labeling, and bulk pricing are available. Protect your food, protect your brand — request your free sample pack from Custom Product Packaging today.
