Sealing food in Mylar bags with oxygen absorbers is one of the best ways to store your emergency foods. A Mylar bag is a vapor barrier bag that blocks oxygen, moisture and light, the three big enemies of food storage. Think of it as a flexible metal can. Many folks get by just fine with using only food grade buckets and oxygen absorbers. Most foods will keep for years stored that way. However, the problem is that plastic is a very poor vapor barrier and over time oxygen and moisture will actually work its way right through even a 5 gallon bucket, right into your stored products. Using a Mylar bag greatly reduces this and can add years to the storage life of your emergency supply.
Mylar bags come in many different sizes, thicknesses and styles. You can get them with a zipper on the top and a gusset on the bottom, but the most popular is just the plain open top bag that is sealed with heat. The zip top bags are a handy option for when you are using the product as you can take some out and seal it back up for a short term seal. The zip top is NOT however a good option for long term storage. If you do use the zip top bags it is important to still heat seal the very top before storing away for long term.
The most popular thickness are 3.5 mil for smaller bags and 4.5 mil on 5 gallon size bags. Many folks use the smaller bags and then layer them inside of a 5 or 6 gallon bucket, that way they will not have to open and use up entire 5 gallons of one item. 3.5 mil is the thinnest bag we recommend. When using these you must be careful of what you store in them as some items can poke through the bag from the inside. We do not recommend using the 3.5 mil for vacuum sealing. The 7.5 mil Extreme bags we carry at Mylarbagsdirect.com are a much thicker bag and are a better option for vacuuming, or for storing things with edges like pasta for example. Many folks like the thicker bags for the simple reason that it is that much better of a barrier. They are less prone to pinholes and can be stored just as they are on a shelf, whereas the thinner bags should be inside of another container to protect the bag. Obviously, even the thickest bag will not protect from rodents and it is still a good idea to use a plastic container or bucket of some sort.
Sealing Mylar bags is not difficult. The best option is to use an impulse heat sealer.(like the Hot Jaw sealer we sell at Mylarbagsdirect.com) If the sealer is not long enough to go across the bag, just seal twice overlapping the seals in the center. If you own a Foodsaver or any other brand of vacuum sealer, you can use the seal bar on that to seal the bags. It will not pull a vacuum as Mylar bags do not have the air channel grooves in them like a vacuum sealer bag does, but it works great as a heat sealer. You can vacuum Mylar bags but you must have the more expensive chamber type sealer. Many folks get by quite well sealing Mylar bags with a regular household iron. If you would like to try this option, do a Google search or watch some videos on Youtube about sealing Mylar bags.
Using oxygen absorbers
Oxygen absorbers should come vacuum sealed in a pack of 10-100 depending on the size of absorber. Once the pack is opened the absorbers immediately start to work and you only have so much time before they are used up. Wait to open the absorber bag until you are ready to seal your food. Also, if you are not going to be using them all, be ready to seal the unused absorbers back up so the reaction is stopped and they will be saved to use at another time. You have several options here. If you have a vacuum sealer that is the best way to save them. Just transfer them to the vacuum bag and seal them. Another option is to use a heat sealer and reseal the bag the absorbers came in. The last option is to put them into a glass jar with an air tight lid. The lid should have a rubber seal as it must be air tight. You should not use a jar that is much bigger than needed as the absorbers will have to absorber any oxygen that is inside the jar before the reaction is stopped.
One 300cc absorber is good size for the one gallon size bags. 2000cc is plenty for the bucket size bags. If you want 2000cc it does not matter if you use four 500cc, two 1000cc or one 2000cc absorber. There is no advantage or disadvantage to using one absorber or ten, as long as they add up to the cc you are looking for.
There is a way to tell if absorbers are used up or if they will still absorb oxygen. An oxygen absorber that is still fresh will feel like it is filled with soft powder. (Somewhat like flour) Absorbers that are used up become brittle inside and feel more like they are filled with corse sand. Leave one out for a day then handle it and you will notice the difference.
One common misconception about absorbers is that you can tell how well they worked by if the Mylar bag is vacuumed in on the sides. While it is not unusual for the bag to pull in some, it is important to remember that absorbers will only remove oxygen from the air... not all air. Air is composed of much more than just oxygen, but it is the oxygen you want to get rid of. Also, absorbers added in with a very dry product can take much longer to work (days instead of hours) than if there is a tiny bit of moisture in the air. Don't expect your absorbers to vacuum pack your mylar bags.
A Note on Dessicants:
Dessicants have their place in food storage, especially when storing things like sugar or salt. Sugar and salt does not go bad but it can turn into one hard block in storage. A dessicant or two sealed inside with those items can help keep it loose and usable. Dessicants can keep oxygen absorbers from working properly and is is not usally recommended to use both dessicant and oxygen absrobers in the same Mylar bag. In 5 gallon buckets you may put a dessicant on the bottom of the food item and an oxygen absorber on the top before sealing the bag if you wish. Just do not put them side by side.
What foods to store?
The best food items to put up for long term storage are whole grains like wheat, rice, oats etc. As a rule the more a food item is processed the shorter itís storage life will be. For example, whole wheat will store two or three time as long as ground flour. You are better to put up whole wheat, then stash away a good grinder with it, than you are to store 5 gallon buckets of flour. Be carful in storing things with oils and fats that can go rancid. For example, white rice will store very well, but brown may only store for a few years as is will go rancid. Just because food is sealed in a Mylar bag does not mean it will never go bad. Much has to do with how it is stored. Heat is big enemy. Food stored in your attic will not keep nearly as long as food stored in your cellar.