 |
| Oxygen
absorbers come in a plastic bag. Each absorber packet has a special barrier
to prevent it's contents from making contact with your food. |
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.
Each
bag of oxygen absorbers contains a light pink capsule. This capsule turns to
a light blue color when the bag is opened. It's there to tell you if an unopened
bag has been compromised. It doesn't automatically mean that all the oxygen
absorbers inside are bad as it will change color soon after the bag is opened.
Number
of oxygen absorbers needed: We sell 750cc absorbers. They will absorb 750+
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 the 750cc absorbers in the
#10 cans as we'd rather have a bit of overkill than a little oxygen left in
the can should the absorber become loaded.)
Checking
the same thing with a full 6 gallon bucket of grain or beans, you will have
1890cc oxygen left in the container at sea level. You will need three absorbers.
We can get away with using two absorbers because our facility is at 6,000 feet
and at this altitude there is only an equivalent of 1484 cc of oxygen in the
thinner air.
Be
aware that absorbers are over rated a little bit to give you a fudge factor
if you should leave them out in the air a bit too long. Generally, you have
about 20 minutes before you 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 5 minutes of operation. 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.
