Best Mylar Bags and Oxygen Absorbers for Long-Term Food Storage

Start with thickness, because thin bags are the number one failure

Beginners obsess over the oxygen absorbers and barely look at the bag, which is backward. The bag is the barrier. If it punctures or the seal cracks, the best absorber in the world is sitting in a container that leaks, and your food oxidizes anyway.

Mylar for food storage runs from about 3.5 mil up past 15 mil. The thin stuff is cheaper and it's fine for a small pint bag you'll baby, but for anything that goes in a bucket or gets handled, owners are close to unanimous: go thicker. A heavier gauge resists the tears and pinholes that quietly end a batch, and it takes a cleaner heat seal.

I use FreshUs brand absorbers. They do their thing pretty quick and will absorb more than they are rated for (300cc will absorb maybe double that amount). Other types I have tried like wallaby work very slow and take several days just to get what they are rated for, and no more. As for mylar - the thicker the better to prevent tears and punctures.

There's a catch worth knowing before you sort an Amazon listing by price. Stated thickness isn't always honest, and a bag sold as 7 mil can measure a lot thinner in the hand:

Hey u/meat_smoker can you share the 7 mil bags you use and where you get them? On Amazon the "7 mil" bags I've seen and tried....just aren't. Would love to get a good source for genuine 7 mil (both sides). Thanks if you can!

Treat 5 mil as your floor for anything that matters, and lean toward 7 to 15 mil for bucket liners and anything you'll move around. A little extra thickness costs almost nothing per bag and takes the most common failure off the table.

Match the bag size to how you'll actually eat

The two sizes that cover most people are the 1-gallon bag and the 5-gallon bucket liner. A 1-gallon bag is the workhorse: it holds roughly six to seven pounds of rice, which is a portion you can realistically open and use before it goes stale.

What may work better for you is sealing the rice in one-gallon mylar bags with an O2 absorber. A one-gallon bag holds 6-7 pounds of rice. When needed, you can open a bag, and transfer the contents into an airtight container (like a Rubbermaid cereal container).

The 5-gallon liner is for bulk. It goes inside a food bucket and swallows twenty-five pounds or more, which is exactly why it can bite you: once you cut it open, you've committed to using all of it or watching the rest degrade in the open air.

If it's just you, go with smaller sizes. A 5 gallon bag of oatmeal is a huge amount to use once you open it. Go with 1 gallon, and buy thicker bags, it will help with possible punctures. I use 7 mil bags and have good luck. They are cheaper in the long run.

The move most experienced packers land on is to split bulk grain into several 1-gallon bags and stand those inside a bucket, rather than filling one giant liner. You open one bag at a time, and if mice ever find the bucket you lose a pound, not the whole thing. Reserve the 5-gallon liners for the staples you're truly sealing away and not touching.

The oxygen absorber math is where beginners go wrong

Oxygen absorbers are rated in cc, which is just how much oxygen one packet can swallow. The whole game is matching total cc to the air volume in the bag. Too little and some oxygen survives; more than enough is fine and doesn't hurt the food.

As a starting point: a 1-gallon bag wants roughly 300 to 500cc, and a 5-gallon bucket wants about 2000cc or more. Someone who packed food commercially for a living put real numbers to it:

When we owned and ran a mid size commercial cannery in the 90's, we used D750 CC absorbers for #10 cans and D2000 CC absorbers for superpails. Everyone told us it was overkill "you can get away with a 500cc in a #10 can and 1,000cc in pails"- We went bigger and had better results. A #10 can is roughly a gallon size. A 750CC absorber is going to work better for you.

Notice he sizes up rather than down. That's the consensus: when in doubt, use more, because absorbers stop working once the oxygen is gone and the extra capacity just sits there harmless. The other variable is how airy the food is, since a bag of pasta traps far more air than the same bag of rice:

It depends on what you're storing. If you're storing rice, 1 should work (it'll just take a bit to get all the oxygen). If you're storing something with more empty space (pastas) you'll need more. Just keep an eye on them. I'd say if they aren't vacuum sealed within a week or two, I'd redo them with another. Be sure to heat seal them.

One trap to avoid: if a kit ships with tiny 100cc absorbers and you try to use them in a 5-gallon bag, you'll need twenty or more packets to hit the volume. It's cleaner to buy absorbers sized to your biggest bag and double up on the small ones than to count out a fistful per bucket.

Only pack dry, low-oil foods, and treat this as a safety rule

Mylar and oxygen absorbers are made for one narrow job: dry, low-moisture, low-oil staples. Rice, dried beans, oats, pasta, flour, and sugar are the classic candidates. Anything moist or oily does not belong in here, and this isn't a preference, it's a food-safety line.

"Products intended for longer-term storage must be dry (about 10% or less moisture content). Warning: Botulism poisoning may result if moist products are stored in packaging that reduces oxygen" you don't want to open and allow moisture in.

That warning is the reason you don't seal fresh, damp, or high-oil food in a low-oxygen bag: the low-oxygen environment is exactly where the wrong bacteria can grow. Keep it to things that are shelf-stable dry to begin with.

Two edge cases owners raise constantly. Salt and sugar don't need an oxygen absorber at all, and adding one just makes them clump into a brick you'll chip at with a spoon. And oily foods like nuts or brown rice go rancid from the oil itself no matter how little oxygen is around, so they don't get the decades that white rice does.

Sealing is easy, and a hair straightener does the job

The zipper on a resealable bag is a convenience for after you open it. It is not the long-term seal. The airtight closure comes from melting the mylar shut with heat, and you can do that with a clothes iron or, as a lot of people prefer, a cheap flat hair straightener.

I didn't read your whole post. But. Try a hair straightener for sealing the bags. I found it better than an iron. Seal up most of the bag. Then squeeze as much air as u can. Drop 1-2 pouches in. If 1 doesn't seem to brick it's enough. Add another. Whatever it takes to get desired effect. (Should be bricked the next morning). After u drop the pads in and squeeze remaining air seal Er up

The routine is the same whichever tool you use: fill the bag, drop the absorber in, press out as much air as you can by hand, then run the heat across the top to fuse it. Leave a little headspace to seal, and double-seal the strip if your iron leaves any ripples, because a wavy seal is where air sneaks back in.

Bricking is nice to see, not a pass or fail

Here's the thing that sends new packers into a spiral: they expect the bag to suck down tight like a vacuum-sealed brick, and often it doesn't. That's normal. An oxygen absorber only removes the oxygen, and oxygen is only about a fifth of the air in the bag. The rest is mostly nitrogen, and the absorber leaves it alone.

So a properly sealed bag might shrink a little or barely at all, especially with airy foods like oats or with a bag that had a lot of headspace. That doesn't mean it failed. If you hand-pressed the air out before sealing and the seal is clean, the absorber is doing its job whether or not the bag looks dramatic. Chasing a hard brick is what pushes people toward a vacuum sealer, which is a fine upgrade but not something the mylar-and-absorber method requires.

So what should you buy?

Start with the job, not the brand. For most people the default is a set of thick 1-gallon bags that comes with correctly sized absorbers, so the cc question is already answered for you. That covers rice, beans, and oats for a household without any math.

If you're lining actual buckets with bulk grain, get 5-gallon liners and 2000cc-plus absorbers, and split the overflow into gallon bags so you're never opening more than you can use. If you eat what you store and want to portion it small, a stack of quart and pint bags keeps you from cracking a whole gallon at breakfast. And if you already have bags but keep running short on absorbers, buy a box on its own and double up, because extra never hurts.

Whatever you pick, hold two rules in your head: buy the bag thick, and keep it to dry, low-oil food. Get those right and everything else about this is forgiving.