How To Use Mylar Bags & Oxygen Absorbers for Long Term Food Storage

how to use mylar bags

When I first started prepping, all I heard was people using mylar bags and 5 gallon buckets to store their food. I had no idea why mylar bags were so cool, didn’t know how oxygen absorbers worked and certainly didn’t understand the concept of storing the mylar bags full of food inside of a 5 gallon bucket.

As time went on, I realized that mylar bags with oxygen absorbers are pretty much amazing and even better than vacuum sealing. Though I still vacuum seal, when it comes to long term storage, I use mylar bags.

What are mylar bags?

Mylar bags are made from metalized polyester. The oxygen is removed by the addition of oxygen absorbers.

Why should I use a mylar bag?

Using Mylar bags with oxygen absorbers removes up to 99.99% of oxygen. Even the greatest vacuum sealer on the market only removes around 99.5% oxygen. Sure, that seems insignificant, but that little bit of air really can make the difference in freshness.

Mylar bags are also much ‘tougher’ and more resistant to gas permeability than vacuum sealer bags, due to their metalised nature. Mylar bags can be considered to be like a flexible aluminum can, protecting the contents from not just gas permeability, but also light, heat, pests and damage due to impact and environmental factors.

Material District

There are some misconceptions about mylar bags and oxygen absorbers, though.

Oxygen absorbers will make the bag look ‘sucked in’, kind of like a vacuum sealer.

False. Oxygen absorbers absorb oxygen which is only about 20% of air. While you may see the ‘vacuum’ effect with some things, you won’t see it with everything and that doesn’t mean it’s not working.

Thicker mylar bags are better.

False. The thickness of a mylar bag doesn’t make it better. It may feel more sturdy, but it doesn’t make the oxygen absorbers work better or differently. However, it’s a nice comfort to have mylar bags be a thickness of 5 or 7.

Oxygen absorbers can be reused.

False. You can’t reuse an oxygen absorber. Once it’s been released from it’s vacuum-sealed bag, it begins to activate immediately, you may feel it become warm to the touch, that means it’s working! Once it’s been taken out from the vacuum sealed package, it’s ready to place in your bag and will take around 4 hours to reach maximum absorption. Once they’ve fully activated, they cannot be reused. They’re fine in the sealed bag or container, but once oxygen has been re-established, you’ll need a brand new oxygen absorber before re-sealing.

If you have any unused oxygen absorbers, they need to be vacuum sealed immediately.

So how should you use mylar bags and oxygen absorbers?

What most preppers do is, they get bulk rice, bulk beans, bulk oats, whatever. Then they fill up a gallon or 5 gallon sized mylar bag. Then they’ll place the oxygen absorber inside, seal it and label it. Then place it in a 5 gallon bucket and close it up with a lid. Some will even simply line a 5 gallon bucket with mylar, place an oxygen absorber in then seal it with a lid.

What I do is fill up a gallon sized mylar bag with an oxygen absorber, then place that mylar bag into a large bin with a locking lid. This keeps them organized, plus it keeps it out of reach of critters. You can also place mylar bags inside of buckets, food grade or not.

If you plan to place contents of food directly into a bucket, make sure it’s food grade.

You can also portion out individual serving sizes into mylar bags. Mylar bags can be cut an sealed at the cut ends to make any size bag you want.

Don’t forget to label the outside!

Put the contents, if there are any instructions on how to prepare it, as well as the date that you packaged it on the outside. Write on it with a sharpie, place a blank sticker on it and write on that, whatever works best for you.

What can you place inside of mylar bags?

Here are some ideas:

  • Flour
  • Sugar (NO oxygen absorber)
  • Rice (white), Brown rice can be stored but the oils will make it go rancid quicker than white
  • Dry beans
  • Pasta
  • Dehydrated anything
  • Freeze dried anything
  • Bread crumbs
  • Powdered milk
  • Spices/herbs
  • Oats
  • Seeds
  • Coffee
  • Protein powder
  • Dry cereals

That’s just a basic list.

Even though the mylar bags are held inside of a bucket or bin, the food will still need to be kept out of direct sunlight and in as dark conditions as possible.

Download my shelf life guide to find out how long each type of food will last.

How many oxygen absorbers should I use?

Oxygen absorbers can come in sizes of 100cc-2,500cc. I normally buy the 300cc as just one of those is good for 1 gallon or fewer mylar bags. If you’re lining a 5-gallon bucket with mylar and then filling it, you’ll need a 2,000cc oxygen absorber. There’s no such thing as too many oxygen absorbers, but too little could be a problem. If in doubt, place more inside.

How to seal mylar bags?

I’ve always sealed mine with a clothes iron and it’s worked amazingly well and quickly. You can also use a hair straightener, the heat seal function on a vacuum sealer, or a dedicated heat sealer.

Where to purchase mylar bags?

I purchase my mylar bags and oxygen absorbers exclusively from Wallaby Goods. You can use my code ROGUEPREPAREDNESS for $5 off!

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Morgan is the founder of Rogue Preparedness. She has been a prepper for over a decade. She's a wife, mother of two daughters and is homesteading off grid. She teaches people how to be prepared for emergencies and disasters.

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  1. Hi! I am just learning how to use Mylar bags. Can I put my flour or rice, etc in a gallon size ziplock bag and then put it in the Mylar bag with an oxygen absorber! Also would I put the oxygen absorber inside the ziplock bag or the mylar bag? Thanks!

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