Riots, Blizzards, Quakes, Strikes, War, Invasion, Tsunami – None of the Following Matters if you Don’t have Water.

Part One: Choosing which Mylar and Using Oxygen Absorbers

Mylar bag food storage can give you up to 25 years of non-electric, safe, food storage.

Mylar is a strong polyester transparent film. When sandwiched around a thin layer of aluminum, mylar bags are great for long term food storage. They block light, block air, and block moisture – all elements that cause foods to spoil.

NOT ALL MYLAR IS CREATED EQUAL. You should not be able to see your hand through a side of a mylar bag intended for long term use. And you should definitely NOT be able to photograph your treeline from a camera inside your mylar bag. If you can, as I did here, you do not want to use that mylar for long term storage.

Storage-quality mylar has a very thin fragile center layer of aluminum between two sheets of mylar. These block out light, air, moisture. This is the mylar to use. However this aluminum layer can be easily damaged. Be mindful, and do not fold your mylar bags. Larger bags should be rolled if you can’t store them flat.

The mylar bags I use are 5.25 mil to 5.4 mil thick and have the aluminum lining. (Mylar can also be purchased at 7 and 7.5 mil for heavier duty applications.) From many vendors you can order individual sizes of aluminum-lined bags which I strongly recommend when you’re first starting out.

With single bags you can check out the quality of the mylar, (see treeline above…), have some fun checking out sizes, see what products fit in what size bags, see what’s comfortable for you and your situation. The prices are very reasonable, 27 cents, 31 cents, 89 cents, etc. Companies also sell bulk bag packages with or without oxygen absorbers.

On eBay I found rolls of mylar, 11 inches by 50 feet (pictured here) with packs of oxygen absorbers. You can use these to custom cut bags to your own needs. Make sure you get the 5 1/4 mil aluminum-lined mylar. Often mylar retailers sell both qualities, with or without the aluminum.

Mylar bags go from small pint-sized (6” x 8”) to large 5 gallons (20” x 30”). Most of them come in two styles: plain; or zip lock with a stand-up pleat or gusset in the bottom. However, not all zip bags have the pleat. Remember that when you order.

I seal my food in the plain bags. I just cannot bring myself to trust a pressed zip lock closure to stay airtight for two dozen years.

However, zip locks are undeniably handy for resealing whatever it is you just opened! Because of the pleat on the bottom, the zip lock bags are usually shorter than the plain bags by about two inches. Also, the opened pleat allows them to stand up. Zip lock bags need to be heat sealed above the zip lock but take care not to seal the zip lock itself.

There is also a “Tamper Evident” zip mylar bag available that comes with the top already sealed. It is filled from the bottom and then the bottom is heat sealed. Also, many mylar retail sellers are now selling vacuum seal mylar bags. Just make sure your vacuum unit is hot enough to seal through mylar. The cheaper units are not. Double sealing is an idea.

Please note, however. It is NOT necessary to vacuum seal a properly prepared mylar bag with the right-sized oxygen absorber inside. Earlier write-ups encouraged vacuum sealing but it is generally more difficult, more time consuming, gains you nothing, and increases the chances of a puncture in your mylar.


Oxygen absorbers are what make the whole system work.

Do not confuse oxygen absorbers with desiccants. Desiccants absorb moisture. Oxygen absorbers absorb oxygen. Some people recommend that you NOT seal both in a mylar bag. Others say if you are going to use both, put the desiccant at the bottom, fill your bag, then put the oxygen absorber on the top. To date, I have not used desiccants in my food bags.

Oxygen is about 21% of air. Oxygen causes your food to spoil. Your oxygen absorber (size chart at the end) will absorb that oxygen. This will result in a dimpling of the mylar bag. It will not look totally vacuum-sealed because 80% of the “air” is still in the bag. But all the oxygen should be gone.

My absorbers have iron dust inside. This dust attracts the oxygen which turns the iron to inert rust. My absorbers are covered in food grade tyvek. The oxygen goes in but the rust does not come out. I have had no leaks.

The “CC” designation on your oxygen absorbers refers to “cubic centimeters”. It is simply a size designator. The more cc’s your absorber has, the more cc’s of oxygen it can absorb.

The very last thing you do before your final seal on your bag is to put your oxygen absorber into your filled mylar bag, because as soon as that absorber packet hits any air, it starts absorbing oxygen. What you want is for it to absorb the oxygen inside your bag. So, you unwrap the absorber, stuff it into your filled mylar bag, carefully push out any extra air, and then do the final seal on the bag.

NOTE: Oxygen absorbers have little shelf life. Most are sold in bags of 50. What a waste! Unless you are heavy-duty into doing a regular production line of mylar bagging, a bunch of these will lose their effectiveness before you ever get them near a mylar bag.

Yes, you can use some and then vacuum seal the remaining ones. That’ll work for a while. Some people store them in covered mason jars. (Of course, shortly there will be no oxygen in that mason jar.)

And there are vacuum sealed mason jars, too. Your time. Your preference.

One way to test the oxygen packet is to feel it. A fresh packet will feel like it is filled with fine flour. An old packet will feel more like it’s filled with hard sand, sort of brittle. (Of course, if your 50 absorbers are vacuum sealed in plastic, the whole package feels hard…..) Most packages now come with a pink oxygen indicator. It turns blue when exposed to oxygen.

THE GOOD NEWS. Someone finally figured this out! Available online and likely elsewhere are smaller packages of oxygen absorbers! The 2,000 cc packets come individually wrapped. 100 cc and 300 cc packets come in 5-to-a-sealed-pack.

So, you set up five small-to-medium-sized mylar bags, fill them, and seal them part way. Then you open your 5-in-a-pack, put in one oxygen absorber, push out the air, and do the final seal. You keep the other absorbers covered in their package plastic while you do this. Then you move to Bag Two-put in an absorber, push out the air, do the final seal. Then Bag Three-put in an absorber,…..

And so you will have good oxygen absorption and little waste.

A Practical Note: Mylar bags are uniquely built to withstand the partial vacuum that the oxygen absorbers create. It is why they dimple. Five gallon food buckets are NOT created to withstand vacuums. If you put one or two 2,000 cc absorbers just loose in the bucket and seal it tight and then try to stack it you may find a disaster on your hands. It is probable that at least one of the buckets will crumple and with it your food supply. Putting the absorbers into the mylar bags prevents this.

A Second Practical Note: Sealing up a five gallon bag of beans sounds real good from this end of “the event”. But what happens when you need to open that 5 gallon bag? Where is the water going to come from to soak and then cook those beans? How do you reseal a 5 gallon bag full of beans? For that matter, who’s going to carry that 5 gallon pail full of beans?

It might be good right here to remember to include in your supplies some kind of clips to close the mylar bags once you’ve opened them.

More practicality… Mylar (aluminum-lined mylar that is) blocks light, air, and moisture. However it is subject to punctures. This would introduce oxygen and moisture and pretty much guarantee the ruination of all your work. Follow me here.

All of the long term food sales sites I’ve visited recommend storing their mylar sealed long term foods in plastic buckets, and many of them supply the bucket. This is a problem on several levels.

One, some of their mylar is see-through (no aluminum). Two, light goes through most plastic bins and buckets. Three, odors can permeate plastic. Four, air can penetrate plastic, or lids can leak.

Now, have you ever seen what a rodent can do to a plastic bucket………? They love eating plastic! Have you ever seen what a bear can do to plastic? Imagine what a bear can do to a mylar bag – especially if he’s been trained to think it has potato chips inside! And do we all know how clever those cute little raccoons are?

And for those of you who are currently rodent-free: What will some of our areas look like after three weeks of no garbage pickup?

The best long term storage answer I have is metal garbage cans, spray painted outside with XO black matte (most Rustoleum spray paint cannot be used on galvanized metal), the lids secured with a strong bungee cord strap. Locking the can to a tree is good also.

In addition to four-legged critters you may also have two-legged food marauders. Be guarded in discussing your food and water preparedness.

Mylar bags also available for special equipment. Usable length is 44”.

Coming soon in Part Two….. SEALING MYLAR and OXYGEN ABSORBERS

Taking your future into your own hands………

© 2016 Ronnie Herne – All Rights Reserved

Print Friendly, PDF & Email