Food storage

Buckets, Mylar Bags, and Oxygen Absorbers: DIY Long-Term Food Packing

The cheapest long-term food storage is the kind you pack yourself: bulk rice, beans, oats, and wheat sealed in Mylar bags with oxygen absorbers, inside food-grade buckets. Done right, dry staples packed this way keep for 20 years or more. Done wrong, they mold, hatch insects, or absorb off-flavors within a season.

This guide covers the materials, the absorber math, the packing process step by step, and the four mistakes that account for nearly every failed bucket.

Why oxygen is the enemy

Oxygen feeds the three things that ruin stored food: oxidation (rancid fats, lost nutrients), insects (eggs in grain hatch when oxygen is present), and aerobic microbes. Remove the oxygen and seal it out, and dry food essentially goes dormant. Mylar film is the barrier, the oxygen absorber does the removing, and the bucket is just armor against rodents, light, and bumps.

Freezing flour and grains for 72 hours before packing is a common extra step to kill insect eggs. It helps, but a properly sized oxygen absorber in a sealed bag does the same job by suffocation, and it does it inside the sealed package where it counts.

Sizing oxygen absorbers without guessing

Absorbers are rated in cubic centimeters (cc) of oxygen they can absorb. A gallon of empty air space holds roughly 800 cc of oxygen, and dense food displaces most of the air in a full bag, so the working rule is 300 to 500 cc per gallon of container for well-filled bags. For a full 5-gallon Mylar bag, 2,000 cc total is the common recommendation; use more rather than less, since leftover capacity does no harm.

Absorbers start working the moment their package opens and exhaust themselves in open air within about an hour. Work in batches: open the absorber pack, seal what you need into each bag quickly, and vacuum-seal or jar the unused absorbers immediately.

What NOT to pack this way

• Brown rice: the bran oil goes rancid in 6-12 months even sealed. Store white rice instead.
• Anything moist: dried fruit with high moisture, brown sugar, or home-dried food that is leathery instead of brittle can mold inside a sealed bag.
• Ground spices and mixes with oils or dairy: shorter lives; store in jars with small absorbers instead.
• Baking soda, baking powder, and salt need no absorber at all; salt and sugar keep indefinitely in a sealed bucket on their own (sugar should never get an absorber, it turns to a brick).

Storing the finished buckets

Stack no more than three high, off the floor, in the coolest dark place you have. Write the contents and pack date on the bucket and on the bag inside. Keep one 'open' bucket per staple in the pantry and eat from it, so the sealed stock stays sealed and the food is always familiar.

Step-by-step: put it into practice

Tick each step off as you complete it. Your progress is saved on this device.

• Buy food-grade 5-gallon buckets with gasket lids and 5-gallon Mylar bags (4-7 mil)
• Open one staple at a time; check it is dry, clean, and pest-free
• Line the bucket with the Mylar bag and fill, settling the food to reduce air space
• Drop in 2,000 cc of oxygen absorbers per full 5-gallon bag
• Heat-seal the bag, leaving a small gap; press out extra air, then seal the gap
• Close the bucket, label contents and date on bag and bucket
• Store cool, dark, off the floor; check one bucket per season on rotation

Reset checklist

Sources

• USDA, food storage and shelf life guidance
• Utah State University Extension, food storage resources

Facts checked against the sources above. Last verified: November 11, 2026. If a figure here ever conflicts with an official source, the official source wins, and we want to hear about it via the contact page.