If you are managing your food storage on your own (and you really should be), then you’ll probably need oxygen absorbers (aka Oxygen Scavengers). Oxygen absorbers literally “absorb” oxygen. This is done through a chemical reaction that you’ve probably heard of: rusting. If you’ve ever seen metal rust, then you’ve seen “oxygen absorption” in action.
If you’ve seen cars up north rusting, then you’ve really seen what’s at work. Oxygen absorbers contain a fine mixture of iron and salt. When oxygen mixes with them, it causes the iron to rust. This reaction uses up the oxygen within a mylar bag or a mason jar.
Why Use Oxygen Absorbers
Oxygen absorbers have many uses, but their primary use in prepping is to remove any remaining oxygen from foods packaged in mylar bags.
Aerobic bacteria require oxygen in order to survive and an oxygen absorber starves them of that. Additionally, oils go rancid in the presence of oxygen, so oxygen absorbers help to lengthen the shelf life of foods containing oil. This is especially important for foods like brown rice.
Oxygen absorbers are a very inexpensive way to protect your preserved foods and I highly recommend them if you plan to make your own food storage, rather than buy it already done for you.
What Size Oxygen Absorber to Use
The hardest part of purchasing oxygen absorbers is understanding how many you need, or how big they should be. Oxygen absorbers are measured in cubic centimeters (cc’s). So, if you had a cube that measured 10 centimeters wide, by 10 centimeters tall by 10 centimeters deep, the cube would be:
10 x 10 x 10 = 1,000 cubic centimeters
With that little bit of information out of the way, here are the volumes of common containers used for preserving food. They are rounded up to the next quarter of a thousand cc’s to be safe.
Volume of Common Types of Containers
First, to determine how many you oxygen absorbers you need, or how large a size to purchase, we need to first figure out just how big of a container you’re trying to fill. Below is a table of common containers and their sizes in cubic centimeters.
|Container Size||Volume (in cc)|
|1/2 Pint Mason Jar||250 cc|
|1 Pint Mason Jar||500 cc|
|1 Quart Mason Jar||1,000 cc|
|1 Gallon Mason Jar||4,000 cc|
|#10 Can||4,000 cc|
|3 Gallon Pail||11,500 cc|
|5 Gallon Pail||19,000 cc|
|6 Gallon Pail||22,750 cc|
Accounting for occupied space
Now, you might be thinking “those must be huge oxygen absorbers for a 5 gallon bucket!” But you would be wrong. You have to remember that your food will occupy space. Which means oxygen will be pushed out of the bucket you’re using.
For example, if you’re packing rice into a bucket, you won’t need very large oxygen absorbers because rices is very dense and occupies most of the space in the bucket or bag. As an example, if you were packing a bucket with tennis balls, then you would need more oxygen absorbers as the tennis balls will have a lot more space between each other.
Here is a great article explaining how you can estimate how much space your food will occupy so you can purchase the right size oxygen absorbers. If you want something a little less technical, then this is a great article. Always remember: it’s better to buy oxygen absorbers that are too large and spend a little more rather than throw out a whole bucket of rancid brown rice.
Video: Using Oxygen Absorbers
How to Buy Oxygen Absorbers
I’ve compiled a list of the best places to purchase oxygen absorbers at fair prices. Beware of purchasing “kits” that come with Mylar bags and oxygen absorbers.
Often, this causes the prices to be inflated. It might be slightly more convenient, but you’re better off purchasing them separately to get the best price.
Your best bet is to buy your mylar bags and oxygen absorbers separately so you know you’re getting a good price.
Places to get oxygen absorbers: