Long Term Food Storage with Mylar

Canning, Drying, Smoking, Packaging, etc.
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Long Term Food Storage with Mylar

Post by Blackthorn-USA » Thu May 02, 2013 6:15 pm

I wanted to do a quick tutorial on how to package dry goods for long term storage using Mylar bags and oxygen absorbers. Storing foods in Mylar can extend the self life on many products to 20 or even 30 years. Mylar in its basic form is made from polyester resin and is transparent. Mylar bags used for food storage are made by laminating a layer of aluminum between two sheets of Mylar. The aluminum/Mylar sheet is a very effective barrier to oxygen, moisture and light, all enemies of stored food.

Mylar bags come in many different sizes and thicknesses. I have used bags made for 5 gallon buckets, one gallon and one quart sizes. I use the 5 mil thick bags and wouldn’t recommend using anything below 4.5 mil for food storage. Mylar bags have a high tensile strength but are susceptible to puncture damage if handled carelessly.

Oxygen absorbers eliminate the need for gas flooding with CO2, Nitrogen etc. These cool little packets are made of a chemical compound, the active ingredient of which is a powdered iron oxide. While they are not edible, they are not toxic. When used with proper packaging and sealing, the oxygen in the packaging is greatly reduced.

Oxygen absorbers are completely safe. No harmful gases are created and the oxygen does not remove the fresh smell and taste of the product. The oxygen absorbers I use bring the oxygen level down reliably to .01% or less. The absence of oxygen in the bag extends shelf life, prevents growth of mold and other aerobic pathogens and spoilage organisms. It also eliminates the need for additives such as BHA, BHT, sulfur dioxide, sorbates, benzoates, etc.

The only other tool you will need is a common clothes iron to seal the bags. I have heard of people using electric hair straighteners with success and of course you can buy factory sealers made for the task. I find the clothes iron works just fine.

On this day I was sealing up 100 pounds of flour, 50 pounds of white wheat and 80 pounds of white rice. These had all spent the last week in the deep freeze to kill off any insects that may have been in the bags. I generally remove them from the deep freeze and let them come up to room temperature overnight before bagging them. I’m using 1 gallon bags here and will get three to a bucket.


First off you want to fill as many bags with food as you have oxygen absorbers for. I fill them about 2/3 full leaving room for them to be sealed easily and remain malleable enough to fit into a bucket.


Once you have your bags full and lined up, open your oxygen absorbers and drop one into each bag. No need to bury them, just toss them in.


Oxygen absorbers start working immediately once exposed to air so you now need to work quickly. Don’t panic, just seal up the bags as quickly as you can. If you have more oxygen absorbers than you are going to use you can store them in a small jar or vacuum seal them so they stay fresh. A fresh and good oxygen absorber will be flexible when you bend it with your fingers. An old used one will be quite hard.

To seal the bag set your iron on cotton or wool setting. With your hands press the top of the bag shut pushing out as much excess air as is easy. The oxygen absorber will get the rest out, no need to worry about pushing it all out by hand. Flatten and align the edges of the bag and run the iron across a couple times to seal it. It’s quite easy to see the bag sealing together. I found I could set the bag on the second drawer down and the counter was the perfect height. Some people will seal all but an inch or so of the bag and then press out any other air they can before sealing the last inch. I don’t do this but do what works for you.


Once sealed I will press on the bag just to make sure it holds air and to even out the food inside. I do this right after sealing because the oxygen absorber will remove that air fairly quickly.


Once my bags are sealed I write the date and contents on each bag and put them in buckets. The buckets do NOT need to be food grade. They are only to protect the bags and make storage and transport easier. I find that laying the bags in on their side easiest as the food doesn’t want to settle to the bottom of the bag.


Here you can see the bags are already shrinking down from lack of oxygen.


Set your bags in the buckets and then set the bucket upright.


As the oxygen absorbers remove all the oxygen left in the bag they become rigid and won’t be easy to move around in the bucket. As you can see in this picture they have a vacuum packed appearance. You’ve probably seen vacuum packed foods that are rock hard until you break the seal, that’s how these get. This is why I lay them in on their sides to keep them from locking each other into the bucket as they harden.


Other size bags, with the exception of the 5 gallon size, are done the same way. I like to put in three gallon bags of flour or wheat and then a couple quart bags of salt, baking soda or something in the space beside the gallon bags. Just makes more sense to me than having a 5 gallon bucket of salt and those products are used with the flour. Label your buckets for contents and snap on the lid. No need to seal the bucket lid beyond it’s built in seal.

Once you open the buckets for use, the snap on lid can be replaced with a Gamma Seal lid for easy re-sealable access while you are using the food.

That’s really all there is to it. It’s a simple process once you have your food, bags and equipment laid out. Working with oxygen absorbers requires you to move quickly but again, that doesn’t mean you have to race the clock. The absorbers I use have a greater capacity than they list and that also gives you a little extra leeway. Anyhow, slow is smooth and smooth is fast. I generally won’t do more than 20 at a time.

Oxygen absorbers are required as follows:
• 5 Gallon bags use a 2000cc oxygen absorber
• 1 Gallon bags use a 300cc oxygen absorber
• 1 Quart bags use a 100cc oxygen absorber
For less dense food like pasta, you should double the quantity of oxygen absorbers.

Good luck and be sure to post your experiences here
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Re: Long Term Food Storage with Mylar

Post by kaithmilton » Mon Aug 26, 2013 6:27 am

Your idea about the Mylar bags id very good. They are very good source to keep food store very long time even in fresh way. Mylar bags come in many different sizes and thicknesses.

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