Mylar Bags & Oxygen Absorbers: Complete Long-Term Food Storage Guide
Mylar bags with oxygen absorbers are the single most cost-effective upgrade you can make to your emergency food storage. White rice stored in a paper bag lasts 1–2 years. The same rice sealed in a mylar bag with an oxygen absorber lasts 25–30 years. For roughly $1–2 per bucket, you transform cheap bulk staples into a quarter-century food reserve. This guide covers exactly how the system works, what foods benefit most, step-by-step sealing instructions, and the best products to buy.
How the Mylar + Oxygen Absorber System Works
Two mechanisms work together to extend food shelf life dramatically:
Mylar Bags: Barrier Against Moisture, Light, and Pests
Mylar is a type of polyester film with an aluminium layer: it creates a nearly impermeable barrier against:
- Moisture: The #1 cause of food spoilage: mylar keeps water vapour out
- Light: UV light degrades fats, vitamins, and flavours: the aluminium layer blocks all light
- Pests: Insects cannot chew through mylar (though rodents can: always use inside a hard container)
- Oxygen transmission: Far lower oxygen permeability than standard plastic bags
Oxygen Absorbers: Remove the Remaining Oxygen
Even after heat-sealing a mylar bag, residual oxygen inside causes oxidation, fat rancidity, and insect egg hatching. Oxygen absorbers contain iron powder that reacts with oxygen: “absorbing” it within 2–4 hours until the bag atmosphere reaches less than 0.01% oxygen. At this oxygen level:
- Insects and insect eggs die (all stages require oxygen)
- Oxidation of fats stops: prevents rancidity
- Aerobic bacteria cannot survive
- Vitamin degradation slows dramatically
Which Foods Benefit from Mylar Storage
Excellent Candidates (25–30 Year Shelf Life)
- White rice (brown rice contains oils that go rancid even without oxygen)
- Hard winter wheat berries
- Dried pinto, black, kidney, and navy beans
- Rolled oats
- All-purpose flour (white; not whole wheat which goes rancid)
- Cornmeal (degermed / degerminated only)
- Powdered whole milk
- Freeze-dried vegetables (if repackaging from bulk)
- Hard candy (low moisture)
- Pasta (white, dried)
Do NOT Use Oxygen Absorbers With
- Sugar: Creates a solid brick when oxygen is removed: use silica desiccant only, not O2 absorbers
- Salt: Doesn’t need O2 absorbers; salt is self-preserving
- Brown rice: High oil content goes rancid regardless; doesn’t benefit from O2 absorption
- Whole wheat flour: Same issue: oils go rancid; 6-month shelf life maximum even sealed
- Foods above 10% moisture: High moisture + no oxygen = anaerobic bacteria (botulism risk); dried foods only
Step-by-Step Sealing Instructions
- Gather equipment: Mylar bags, oxygen absorbers (appropriate size for bag), food-grade 5-gallon buckets with lids, hair straightener or clothes iron, scissors, and a permanent marker
- Work quickly once O2 absorbers are opened: Oxygen absorbers begin activating immediately on exposure to air: seal them within 15–20 minutes of opening the package
- Fill the bag: Pour your dried food into the mylar bag, leaving 3–4 inches of headspace for sealing
- Drop in the oxygen absorber: Place the correct number of absorbers on top of the food (see sizing guide below)
- Remove excess air: Squeeze the bag gently to remove as much air as possible before sealing
- Heat seal the bag: Fold the top of the bag over 2–3 times, then run a hair straightener or iron across the fold for 3–4 seconds with firm pressure. Seal across the full width of the bag in one smooth pass. Check for complete seal by trying to pull the fold open.
- Label immediately: Write contents and date on the bag with permanent marker
- Place bag in bucket and seal: Store mylar bags inside a 5-gallon bucket for rodent protection and stackability
- Check bags within 24 hours: A properly sealed bag with oxygen absorbers will be noticeably vacuum-tight (the bag will compress around the food). If the bag is still puffy, reseal.
Choosing the Right Bag Size
| Bag Size | Container | Use |
|---|---|---|
| 1-gallon (10×14″) | 1-gallon jar or container | Single-use packages; individual meal sizes; small amounts of specialty items |
| 5-gallon (18×28″) | Standard 5-gallon bucket | Standard choice for bulk staples: rice, oats, beans; one bag fills one bucket |
| 6-gallon (20×30″) | 6-gallon bucket | Extra capacity for the same labour; slightly more efficient per pound |
Choosing Oxygen Absorbers
Oxygen absorbers are rated in cc (cubic centimetres of oxygen they absorb). Match the absorber to your bag size:
| Bag/Container Size | Absorber Size Needed | Qty per Container |
|---|---|---|
| 1-quart jar | 100cc | 1 |
| 1-gallon bag | 300cc | 1 |
| 5-gallon bucket | 2000cc | 1 (or 2× 1000cc) |
| 6-gallon bucket | 2500cc | 1 (or multiple smaller) |
Product Recommendations
Mylar Bags 5-Gallon (50-Pack) + 2000cc Oxygen Absorbers (50-Pack) Bundle
The most cost-efficient way to buy mylar bags and oxygen absorbers is as a bundle with matching quantities. A 50-bag, 50-absorber kit gives you everything needed to seal a complete 90-day food supply for 1–2 adults across multiple buckets. The 5-gallon mylar bags fit standard food-grade buckets perfectly. 2000cc absorbers are correctly sized for 5-gallon containers. All food-grade certified. This purchase turns $35 into 25+ years of storage for hundreds of dollars worth of bulk food.
- 50 bags + 50 absorbers: complete 90-day supply kit
- Food-grade mylar; 2000cc absorbers for 5-gallon buckets
- ~$0.70 per bucket in sealing materials
Food-Grade 5-Gallon HDPE Buckets with Lids (6-Pack)
Food-grade HDPE (#2) buckets are the outer container that protects your mylar bags from rodents, physical damage, and UV light. Always store mylar bags inside hard buckets: mylar alone doesn’t stop mice. A 6-pack covers six 25-lb rice/bean portions: enough for one adult’s 3–4 month supply of bulk grains. The included standard snap lids work for permanent sealed storage; upgrade to gamma seal lids for buckets you open regularly.
- Food-grade HDPE #2: safe for long-term food storage
- 6-pack: enough for a complete 90-day grain supply
- Rodent-proof hard container for mylar bags
Mylar Storage FAQ
Do I need a vacuum sealer to use mylar bags?
No: a hair straightener or clothes iron works perfectly to heat-seal mylar bags. A vacuum sealer can be used but is not necessary or even preferable: oxygen absorbers remove oxygen more completely than vacuum sealing, and vacuuming can compact fragile foods. The correct process is: fill, add O2 absorber, manually squeeze out excess air, then heat-seal. The oxygen absorber does the final oxygen removal that makes the bag vacuum-tight within hours.
How do I know if my oxygen absorbers are still good?
Fresh oxygen absorbers feel soft and granular. Spent absorbers feel hard and solid (the iron has fully oxidised). Test before use: if an absorber feels completely hardened before you open the bag, it has already absorbed its capacity and is useless. Buy oxygen absorbers from reputable suppliers in sealed packaging, use within the package shortly after opening, and return unused absorbers quickly to a sealed jar between sessions. Oxygen absorbers stored in an airtight jar after opening remain viable for months.
Is mylar food storage safe? Any health concerns?
Yes: food-grade mylar bags are safe for long-term food contact. Mylar is a trade name for BoPET (biaxially-oriented polyethylene terephthalate) with a food-grade aluminium laminate. It does not leach chemicals into food and has been used for food packaging for decades. Oxygen absorbers are also food-safe: they contain iron powder, salt, and activated carbon, which are benign even if accidentally consumed in small quantities. Always use food-grade certified mylar bags (not craft/hobby mylar) for food storage.