Within the last ten years the advent of oxygen absorbers has brought a revolution to the food storage industry. Their use has increased the storage life of foods and has made the job of putting away food for long term storage much simpler. There are two types of oxygen absorbers used for the storage of Food, "B" absorbers and "D" absorbers. The "B" absorbers require moisture from the food they are packed with to perform their action. A good example would be beef jerky or dehydrated fruit that hasn't been dried until it is brittle. The "D" absorbers contain their own moisture and are better suited for dry pack canning because there isn't enough moisture in correctly dried food to activate the "D" absorbers. The "B" absorbers will last a year after they are manufactured but the "D" absorbers only last 6 months. This is important for you to know so you won't buy a bunch of absorbers, pack them away for two years, and expect them to do their thing when you finally open them. The "B" absorbers also work much slower as they must first absorb moisture from the food they are packed in before they will absorb any oxygen. You can generally leave them out for 2 hours before they reach their advertised minimum absorbing capacity. Because the "D" absorbers have their own moisture built into them, they start absorbing oxygen immediately when opened and reach their advertised minimum much quicker, generally within 20 minutes.

Oxygen absorbers perform their action through a chemical reaction. They contain iron powder which reacts with the oxygen in the air causing the iron powder to rust. When all the iron powder has oxidized, the oxygen absorbers are "loaded" and the absorbing action stops. Remove the oxygen from an active absorber and the chemical reaction stops. Put them back in the air and the reaction starts again until the iron is gone.

Number of oxygen absorbers needed: We sell 500cc absorbers and 300cc. The large ones will absorb 500+ cc of oxygen. A #10 can holds 13 cups or very roughly 3300cc. Air is 21% oxygen. So that empty 3300cc #10 can actually has about 683cc of oxygen in it. If you take a full cup of beans it takes about 0.375 cups of water to bring the water level up to the top of the cup. I've found this to be true with most of the whole seeds I've measured including wheat and rice. This figure is important because it also tells you how much air is in the can when it is full of seeds - 37.5%. With a #10 can full of these products, you now have about 256cc of oxygen left in the can. If you are canning a powder you probably have less air than this but foods like macaroni would have more. Already you can see that one 750cc absorber should do the job nicely, in fact it's a bit of overkill. A 300cc absorber would also do the trick. We use one 500cc absorber in each of our #10 cans as we'd rather have a bit of overkill than a little oxygen left in the can should the absorber become loaded. Actually, on the cans, this is a lot of overkill as the absorbers we use now actually have more than twice as much oxygen absorbing capacity as what they are rated for.

A 6 gal bucket holds 22,740cc. Going through the above calculations, a full 6 gal bucket of grain or beans has about 1791cc oxygen left in the container at sea level. You will need four of our absorbers if you are packing up your food at lower elevations. Our packing house facility is at 6,000 feet and at this altitude there is only an equivalent of 1484 cc of oxygen in the thinner air. Again, because of the oxygen absorber's significant under rating, we only use two 500cc absorbers in the buckets as they will absorb more than twice their rated capacity

Oxygen absorbers are over rated to give you a fudge factor, if you should leave them out in the air too long. Generally, you have about 20 minutes before they reach this advertised minimum. There are variables that determine how fast the oxygen absorbers work, so you shouldn't leave them out any longer than you absolutely have to. But why not get every bit of absorption you can out of them? May I suggest you leave only enough out in the air to take care of maybe 1 or 2 minutes of operation?

 

---

 

Setting Up:
First, don't open the oxygen absorber bag until you are ready to preserve your food. After you open the bag the oxygen absorbers immediately start to absorb oxygen out of the air. So you have to work fast. If you are not planning on using all the absorbers the day you open them up, may I suggest you have a small jam jar set aside. This jar shouldn't be any larger than what you need to hold the excess absorbers. It takes a large mouthed quart jar to hold 50 absorbers. Just like if you were canning produce, get a new lid and boil it in water to soften the rubber seal. Open the oxygen absorber bag and place the absorbers you don't plan on using during the day in it. Put the newly boiled lid on top of the jar and tightly screw down the ring. The absorbers will absorb the oxygen in the bottle then stop working. As this happens the lid on the bottle will pop down, reflecting the partial vacuum that is now inside the jar.

You could also iron the oxygen absorber bag shut with the unused oxygen absorbers inside. This is probably the better solution if you will be using all of them the next time you open it up. For the oxygen absorbers you plan on using during the next hour or two, have a zip log bag set aside to put them in. After they are in the zip lock bag, push out all the air and zip it closed. This will work for you temporarily, but is not a good solution for long term storage of the oxygen absorbers. Use the bottle, or iron the original bag closed for that. At this time you should also be ready to do your packing operation. Be sure all the food you want to preserve, the cans or buckets, mylar bags, heated clothes iron or Eurosealer and board are on hand.

The absorbers you are about to use should be laid out side by side so they are not touching each other. The reason for this is because as they work they generate heat and the hotter they are the faster they will absorb oxygen. (No, I don't suggest you keep them in the refrigerator.) The goal is for them not to absorb any more oxygen than is necessary before they are sealed into the storage container where you want them to do their thing.

 

Pull the bag over the top of a 1 inch board and then... Iron it closed. Now pack the bag down inside the bucket and seal the lid.

The operation:
Open up the mylar bag and put it into the plastic bucket. Then pour the food you are planning on preserving into the bag. Be careful you don't over fill the bag. If you get it too full after the operation is complete you won't be able to get the lid on the bucket. With the bag full of food, throw the necessary number of oxygen absorbers in the bag on top of the food.

Now, lay a board across the top of the bucket so one edge of the board is half way across the top of the opening of the bucket. Lay the bag over the top of the bucket and using the clothes iron or Eurosealer, iron the bag shut. Now that the bag is sealed closed, you can put the lid on the bucket and seal the lid down. It's as easy as that, your finished with that bucket. If you are filling lots of buckets at the same time, you might consider filling ten or more buckets at once. Have all ten of the buckets at the stage where the oxygen absorbers are to be thrown in. Then quickly add the absorbers to each bucket and quickly iron the bag shut. This would save your oxygen absorbers from having to be out in the air any longer than necessary. Before you started sealing your first bucket, you'd pull the absorbers out, lay them side by side, and complete the process on each of the ten buckets as quickly as possible. With a little practice, you should be able to easily seal the ten bags in 5 minutes or less. With all the bags ironed shut, install the ten lids on the buckets, and you are done. If you are so lucky as to have access to a canning machine, the job is even simpler. Just toss an oxygen absorber on top of the food before you seal the lid on the can. It's as easy as that. If the oxygen absorbers are working they will create a vacuum. After a few hours the lids on the cans will pop down or the mylar bags will pull in around the food in the buckets.

---