What Size Oxygen Absorber for a 1 Gallon Mylar Bag?

The recommended oxygen absorber size for a 1 gallon Mylar bag is 300cc to 600cc. This amount safely removes the remaining oxygen after the bag is filled, helping dry foods stay fresh for long term storage.

Finding the correct size of Oxygen absorber to use when sealing a one gallon Mylar bag is critical for long term food storage. Choosing the wrong size of Oxygen Absorber can result in spoilage, mold, bugs, loss of flavor, and waste of your product. Choosing the right size of Oxygen Absorber will allow your food to last for many years and even decades.

This article will show you the difference of each size of Oxygen Absorber and why it matters.

The Quick Answer

For a standard 1 gallon Mylar bag, you typically need:

300cc to 600cc oxygen absorber

Most food storage experts recommend 500cc as the safest choice because it accounts for air trapped between food particles.

Why Oxygen Absorber Size Matters

Oxygen Absorbers do not completely remove all of the air from the Mylar Bag. They only absorb the Oxygen which is approximately 21% of the air in the Mylar Bag.

A 1 gallon bag holds about 3,785 cubic centimeters of air.

21% of that is oxygen:

3,785 × 0.21 ≈ 795cc of oxygen

But here is the catch:

When the bag is filled with food, most of that air is displaced. The actual oxygen left inside depends on the food type.

"When determining oxygen absorber size, you must account for residual headspace and the oxygen trapped between product particles. Choosing a slightly larger capacity absorber provides an added safety margin to ensure oxygen levels drop below the threshold that supports oxidation or microbial growth." - Dr. Keith R. Schneider, Food Microbiology Expert

Not sure how to seal your bags properly? Read our guide on how to close Mylar bags.

How Food Type Affects Amount of Needed

Food types have an effect on how much product you need to buy.

1. Dense Foods (300cc to 400cc)

With dense foods, the space left for air in the storage container can be minimal;

Some examples of this type of food include:

• White rice
• Beans
• Wheat
• Pasta
• Oats

Usually 300cc - 400cc is sufficient for these products; however, for some people using 500cc.

2. Light or Airy Foods (500cc to 800cc)

Light or airy foods have a lot of air present in the storage container and have large air pockets that help contain oxygen.

Examples include:

• Cereal
• Freeze dried foods
• Dehydrated fruit
• Powdered mixes
• Snacks

500cc -800cc is an appropriate amount needed to store these types of foods.

The General Rule that Most Preppers Follow

When in doubt use 500cc of oxygen absorbers for every one gallon Mylar bag.

Too small = bad

Too large = good

You can’t over absorb the oxygen when it comes to damaging desiccants.

Important Things to Remember about Oxygen Absorbers

Oxygen absorbers should only be used with dry foods.

Dry Foods, such as:

• Grains
• Beans
• Flour
• Pasta
• Powdered Milk

Do not use with:

• Moist Foods
• Fresh Food
• Sugar / Brown Sugar
• Salt

Sugar and salt will turn rock hard.

Choosing the right thickness matters just as much as sealing. Learn how thick Mylar bags should be for food storage.

Signs You Used the Right Sized Absorber

Once the bag has been filled, sealed, and placed in storage the bag should:

• Tighten up around food
• Feel like it has been vacuum sealed
• Not puffy / airy

If the bag is still puffy when in storage, you either used too little of an absorber or you allowed the air into the bag before you sealed it up tightly.

Shelf-life of Dry Foods When Properly Sized

When using the proper size oxygen absorber as well as a heavy mylar bag and sealed bucket the expected shelf-life of the food will be:

•Rice, wheat, beans - 20 to 30 years
•Pasta, oats - 10 to 20 years
•Freeze-dried - 25 + years

Wondering how long your food will actually last? See how long different foods last in Mylar bags.

Typical Mistakes

• Using a thin mylar bag
• Opening the oxygen absorber pack before sealing
• Not heating sealing enough
• Storing in hot areas
• Not putting a label on the back or date of product

custom mylar bags oxygen absorbers

Why Brands Pair Oxygen Absorbers with Custom Mylar Bags

Combining an oxygen absorber with a custom Mylar bag will greatly help a company extend the life of products but will also maintain the freshness, flavor, color, and potency of products. With the removal of oxygen from the sealed pouch, brands can eliminate oxidation, stop mold from growing, prevent insects, and keep a product from degrading. This is particularly important when packaging foods, supplements, coffee, pet treats, and other products sensitive to oxygen.

Additionally, brands will be able to use fewer preservatives in their products, maintain the quality of products during transportation and storage, and provide the customer with a better experience when the product is opened. While the custom Mylar bag will provide the necessary barrier for light, moisture, and air; the oxygen absorber will remove what cannot be removed through sealing alone; therefore the Mylar bag and oxygen absorber combination create a packaging solution that is much more effective together than either individually.

Final Recommendation

For a 1 gallon Mylar bag, use a 300cc to 600cc oxygen absorber. Most people choose 500cc to ensure all oxygen is removed, especially for foods with small air pockets like rice, beans, or pasta.

If looking for one product that works, all scenarios, then use a 500cc oxygen absorber with any 1-gallon mylar bag. It is your best option for all dry food.