Friday, January 1, 2016

Oxygen Absorber, How Do You Know if it’s Working?

Two days ago, I stored some more Elbow Pasta in 1 gallon amounts using Mylar Bags and Oxygen Absorbers. For those not familiar with using them here are a couple photo’s showing fairly well what to expect if you have done the procedures correctly.

Remember that the air we breath is 80% nitrogen and 20% Oxygen. Nitrogen is good for food preservation but the oxygen must be removed which is the purpose of the Oxygen Absorber.

So, how do you know if you’ve done the procedure correctly? See below.

This photo shows the newly bagged pasta with an oxygen absorber heat sealed inside. The bag has a typical amount of excess air inside right now. You just can’t squeeze it all out at the bag sealing time. The pasta in this photo is loose inside and can be easily sloshed around inside the heat sealed Mylar bag.

In this photo taken of the same Mylar bag 1 day after sealing shows the excess air (oxygen) has been removed or absorbed by the absorber and a tight vacuum has been pulled squeezing the pasta tightly and imprinting it into the Mylar bag. So tightly the bag has become a rigid brick of food. It’s so stiff you can pick the entire bag up by grasping one corner and extending the bag horizontally like a house brick.
If over time the bag relaxes or loses this vacuum it means the bag has leaked air inside from a poor heat seal or the bag has been damaged maybe with a small pin hole from rough handling and the food inside may be compromised.


  1. Thanks Sandy.
    Your blog has been pretty quiet lately, everything OK?

  2. Neat, Mike! How is it accomplishing it? Binding the free oxygen into a tighter molecule (within the o2 Absorber) to reduce the volume of gas/atmosphere within the bag?

    1. O2 absorbers contain iron particles, almost a dust. Iron rusts very quickly. To make any steel rust it takes oxygen and moisture hence the reason you never use desiccants with absorbers. When sealed inside a Mylar bag the iron particles begin collecting the O2 and moisture then begins to rust. This rusting action 'consumes' the O2 thereby reducing the atmosphere inside the bag by up to 20%. (the air we breath is 80% nitrogen and 20% O2).
      Here's more on it: